IBM 000-8697 Manuale Utente

IBM Informix OnLineDatabase ServerAdministrator’s GuideVersion 5.xDecember 2001Part No. 000-8697

x IBM Informix OnLine Database Server Administrator’s GuideMonitor and Archive Physical Log Pages ... 4-38Write a Trailer Page ... 4

2-6 IBM Informix OnLine Database Server Administrator’s Guide

System Architecture 2-7In This ChapterIn this guide, system architecture is interpreted broadly to include OnLinedatabase server processes as well as

2-8 IBM Informix OnLine Database Server Administrator’s GuideInitialization CommandsShared-memory initialization establishes the contents of shared me

System Architecture 2-9Initialization CommandsAs tbinit executes, it reads the configuration file named by the environmentvariable TBCONFIG. Refer to pa

2-10 IBM Informix OnLine Database Server Administrator’s GuideWhat Happens During Shared-Memory InitializationDisk Space CommandsYou can direct OnLine

System Architecture 2-11What Happens During Shared-Memory InitializationShared-Memory Initialization Procedure1. The tbinit process calculates configur

2-12 IBM Informix OnLine Database Server Administrator’s GuideWhat Happens During Shared-Memory InitializationThetbinitprocessusestheconfigurationvalue

System Architecture 2-13What Happens During Shared-Memory InitializationDuringshared-memoryinitialization,diskstructuresanddisklayoutarenotaffected. E

2-14 IBM Informix OnLine Database Server Administrator’s GuideWhat Happens During Disk-Space InitializationStep 9: Document Configuration ChangesThe tb

System Architecture 2-15What Happens During Disk-Space InitializationImportant: Do notinitialize disk space without careful consideration. Aspart ofth

Table of Contents xiChapter 5 How to Improve PerformanceIn This Chapter ... 5-3Disk Layout ... 5-4Optimize Blobspace Bl

2-16 IBM Informix OnLine Database Server Administrator’s GuideWhat Happens During Disk-Space InitializationAfter tbinit finishes computing the configura

System Architecture 2-17What Happens During Disk-Space InitializationNext, tbinit reserves space in the initial chunk of the root dbspace for thephysi

2-18 IBM Informix OnLine Database Server Administrator’s GuideUNIX Kernel and Semaphore-Allocation ParametersStep 8: Change to Quiescent ModeAfterthec

System Architecture 2-19UNIX Kernel and Semaphore-Allocation Parameters The shared-memory lower-boundary address The maximum number of attached shar

2-20 IBM Informix OnLine Database Server Administrator’s GuideUNIX Kernel and Semaphore-Allocation ParametersIf this relationship does not hold, eithe

System Architecture 2-21UNIX Kernel and Semaphore-Allocation ParametersFigure 2-1Shared memorymust be attached toa user process sothat it looks likeco

2-22 IBM Informix OnLine Database Server Administrator’s GuideOnLine User ProcessesOnLine User ProcessesAn OnLine user process is any process that eve

System Architecture 2-23OnLine User ProcessesFigure 2-2illustratesthevirtualaddressspaceof a user processafterthe userprocess has attached to shared m

2-24 IBM Informix OnLine Database Server Administrator’s GuideHow User Processes Attach to Shared MemoryHow User Processes Attach to Shared MemoryOnLi

System Architecture 2-25How User Processes Attach to Shared MemoryStep 2: Calculate Shared-Memory Key ValueWhenauserprocessisreadytoattachtosharedmemo

xii IBM Informix OnLine Database Server Administrator’s GuideChapter 6 DB-Monitor ScreensIn This Chapter ... 6-3Main Menu...

2-26 IBM Informix OnLine Database Server Administrator’s GuideHow User Processes Attach to Shared MemoryThe first shared-memory segment is attached to

System Architecture 2-27How User Processes Attach to Shared MemoryThe user process lays out the first shared-memory segment, which includesthe shared-m

2-28 IBM Informix OnLine Database Server Administrator’s GuideUser Processes and Critical SectionsUser Processes and Critical SectionsA critical secti

System Architecture 2-29OnLine User Process Status and StatesOnLine User Process Status and StatesThe tbstat -u command prints a profile of user proces

2-30 IBM Informix OnLine Database Server Administrator’s GuideOnLine Database Server ProcessThe user process type flags occupy the fourth position of e

System Architecture 2-31Orphaned Database Server ProcessesThe application development tool process and the database server processcommunicate with eac

2-32 IBM Informix OnLine Database Server Administrator’s GuideOrphaned Database Server ProcessesNever kill anOnLine database serverprocesswith theUNIX

System Architecture 2-33OnLine Daemon ProcessesOnLine Daemon ProcessesDaemon processes are OnLine user processes that perform system-widetasks. Unlike

2-34 IBM Informix OnLine Database Server Administrator’s Guidetbundo Daemontbundo DaemonThe tbundo daemon is called by the tbinit daemon to perform cl

System Architecture 2-35tbpgcl DaemonWhen OnLine is initialized, allpage-cleaner daemonsarestarted andplacedin idle mode. As master daemon, tbinit dir

Table of Contents xiiitbload: Create a Database or Table ... 7-47Syntax ... 7-48Specify Tape Parameters... 7-49Cr

2-36 IBM Informix OnLine Database Server Administrator’s GuideShared Memory and Process CommunicationShared Memory and Process CommunicationShared mem

System Architecture 2-37Shared Memory and Process CommunicationFigure 2-4Multiple userprocesses cancommunicate byway of sharedmemory.Unallocated space

2-38 IBM Informix OnLine Database Server Administrator’s GuideShared Memory and Buffer LocksShared Memory and Buffer LocksA primary benefit of shared m

System Architecture 2-39Managing Shared-Memory ResourcesBuffer Exclusive LockA buffer is in exclusive mode, or has an exclusive lock, if a user proces

2-40 IBM Informix OnLine Database Server Administrator’s GuideManaging Shared-Memory ResourcesConsiderwhathappenswhentwo OnLineserverprocessesattemptt

System Architecture 2-41Managing Shared-Memory ResourcesBuffer locks ensure process isolation while user processes contend for thesame shared-memory r

2-42 IBM Informix OnLine Database Server Administrator’s GuideManaging Shared-Memory ResourcesIf an OnLine user process requires a specific latch, how

System Architecture 2-43Managing Shared-Memory ResourcesSemaphoresWhen an OnLine user process attempts to acquire a latch and finds that thelatchisunav

2-44 IBM Informix OnLine Database Server Administrator’s GuideManaging Shared-Memory ResourcesOnLine resolves thedilemma by forcing anabort. When OnLi

System Architecture 2-45Managing Shared-Memory ResourcesThe blobtimestamp onthe disk page changes each time theblob dataon thepage is overwritten. The

xiv IBM Informix OnLine Database Server Administrator’s Guidetbunload: Transfer Binary Data in Page Units ...7-107Syntax ...7-10

2-46 IBM Informix OnLine Database Server Administrator’s GuideManaging Shared-Memory ResourcesIf a program is using Committed Read isolation, the prob

System Architecture 2-47Shared-Memory HeaderOnLine compares the item key with the key value it is searching for. If thevalues match, the item is locat

2-48 IBM Informix OnLine Database Server Administrator’s GuideShared-Memory Internal TablesThe header also contains the OnLine “magic number,” which i

System Architecture 2-49Shared-Memory Internal Tables User processes waiting for the bufferEach buffer header maintains a list of the user processes

2-50 IBM Informix OnLine Database Server Administrator’s GuideShared-Memory Internal Tables The number of chunk entries (pathnames) that can fit on an

System Architecture 2-51Shared-Memory Internal TablesThe minimum value of DBSPACES is 1, representing the root dbspace.OnLine Latch TableThelatch tabl

2-52 IBM Informix OnLine Database Server Administrator’s GuideShared-Memory Internal TablesA byte lock is only generated if you are using VARCHAR data

System Architecture 2-53Shared-Memory Internal TablesEachtblspacetableentryincludesheaderinformationabout the tblspace,thetblspace name, and pointers

2-54 IBM Informix OnLine Database Server Administrator’s GuideShared-Memory Internal TablesOnLine Transaction TableThe transaction table tracks all tr

System Architecture 2-55Shared-Memory Buffer PoolThe last available entry slot in the user table is always reserved for atbmonitor process,regardless

IntroductionIntroductionIn This Introduction ... 3About This Manual... 3Organization of This Manual ... 4Dem

2-56 IBM Informix OnLine Database Server Administrator’s GuideShared-Memory Buffer PoolRegular BuffersThe regular buffers store dbspace pages read fro

System Architecture 2-57OnLine LRU QueuesOnLine LRU QueuesEach regular buffer is tracked through several linked lists of pointers to thebufferheaderta

2-58 IBM Informix OnLine Database Server Administrator’s GuideLRU Queues and Buffer Pool ManagementLRU Queues and Buffer Pool ManagementBefore process

System Architecture 2-59LRU Queues and Buffer Pool ManagementLRU_MAX_DIRTYPeriodically, the modified buffers in the MLRU queue are written (flushed)todi

2-60 IBM Informix OnLine Database Server Administrator’s GuideHow a User Process Acquires a BufferThe following example shows how the value of LRU_MIN

System Architecture 2-61How a User Process Acquires a BufferStep 1: Identify the DataOnLine user processes request a specific data row by rowid. (Refer

2-62 IBM Informix OnLine Database Server Administrator’s GuideHow a User Process Acquires a BufferStep 4: Read the Page in from DiskIf the requested p

System Architecture 2-63Physical Log BufferIf the user process intends to modify the buffer, it acquires a latch on thebuffer and changes the buffer l

2-64 IBM Informix OnLine Database Server Administrator’s GuidePhysical Log BufferRefer to page 2-151 for further information about the physical log.Do

System Architecture 2-65Physical Log BufferThe contents ofthephysical log buffermust alwaysbeflushed to diskbeforeanydatabuffers.Thisruleisrequiredforf

2 IBM Informix OnLine Database Server Administrator’s Guide

2-66 IBM Informix OnLine Database Server Administrator’s GuideLogical Log BufferFirst, the pageiswritten tothecurrentphysical log buffer, filling it.Ne

System Architecture 2-67Logical Log BufferFigure 2-9The logical logbuffer and itsrelation to thelogical log files ondiskCurrent logical logbuffer (now

2-68 IBM Informix OnLine Database Server Administrator’s GuideLogical Log BufferBuffer ContentsLogical log recordsare written continuouslyduring OnLin

System Architecture 2-69Logical Log BufferNote,however, that thiscostofunbufferedloggingisminor comparedto thebenefits of ensured data consistency. (Re

2-70 IBM Informix OnLine Database Server Administrator’s GuideOnLine CheckpointsOnLine CheckpointsThe term checkpoint refers to the point in OnLine op

System Architecture 2-71OnLine CheckpointsOnereasonanadministrator might wanttoinitiate a checkpointwould be toforcea newcheckpoint recordin thelogica

2-72 IBM Informix OnLine Database Server Administrator’s GuideWhat Happens During a CheckpointWhat Happens During a CheckpointThe checkpoint procedure

System Architecture 2-73When the Daemons Flush the Buffer PoolWhen the Daemons Flush the Buffer PoolBuffer flushing is managed by the tbinit master dae

2-74 IBM Informix OnLine Database Server Administrator’s GuideHow OnLine Synchronizes Buffer FlushingHow OnLine Synchronizes Buffer FlushingBufferflush

System Architecture 2-75Write Types Describe Flushing ActivityIfthetimestamponthepageinthebufferpoolisequaltoormorerecentthanthe timestamp for the phy

Introduction 3In This IntroductionThis introduction provides an overview of the information in this manualand describes the conventions it uses.About

2-76 IBM Informix OnLine Database Server Administrator’s GuideWrite Types Describe Flushing ActivityData is always written to the primary chunk first.

System Architecture 2-77Write Types Describe Flushing ActivityIf OnLineis configured for more thanone page-cleaner daemon process,theLRU queues are div

2-78 IBM Informix OnLine Database Server Administrator’s GuideWriting Data to a BlobspaceIn addition, since database server processes must wait for th

System Architecture 2-79Writing Data to a BlobspaceAt the time that the blob data is being transferred, the row itself maynot yetexist. During an inse

2-80 IBM Informix OnLine Database Server Administrator’s GuideWriting Data to a BlobspaceThe blobspace buffers remain until the OnLine server process

System Architecture 2-81Disk Data StructuresDisk Data StructuresOnLine achieves its high performance by managing its own I/O. Storage,search, and retr

2-82 IBM Informix OnLine Database Server Administrator’s GuideOnLine Disk Space Terms and DefinitionsOnLine maintains three additional disk space struc

System Architecture 2-83OnLine Disk Space Terms and DefinitionsFigure 2-11The logical units of OnLine disk space can be envisioned as overlaying the ph

2-84 IBM Informix OnLine Database Server Administrator’s GuideOnLine Disk Space Terms and DefinitionsBlobpageA blobpage is the unit of disk space alloc

System Architecture 2-85OnLine Disk Space Terms and DefinitionsDatabaseA database resides in the dbspace named in the SQL statement CREATEDATABASE. If

4 IBM Informix OnLine Database Server Administrator’s GuideOrganization of This ManualOrganization of This ManualThis manual includes the following ch

2-86 IBM Informix OnLine Database Server Administrator’s GuideOnLine Disk Space Terms and DefinitionsExtents for a single table can be located within d

System Architecture 2-87Structure of the Root DbspaceStructure of the Root DbspaceThe OnLine configurationfilecontains the locationofthe initialchunkof

2-88 IBM Informix OnLine Database Server Administrator’s GuideStructure of the Root DbspaceFigure 2-12Structures withinthe initial chunk ofthe root db

System Architecture 2-89Structure of a Regular DbspaceStructure of a Regular DbspaceAfter disk space initialization, you can add new dbspaces. When yo

2-90 IBM Informix OnLine Database Server Administrator’s GuideStructure of an Additional Dbspace ChunkStructure of an Additional Dbspace ChunkYou can

System Architecture 2-91Structure of a BlobspaceStructure of a BlobspaceAfter disk initialization, you can create blobspaces.When you create a blobspa

2-92 IBM Informix OnLine Database Server Administrator’s GuideStructure of a Blobspace or Dbspace Mirror ChunkFigure 2-15 illustrates the blobspace ch

System Architecture 2-93OnLine Limits for ChunksIf the primary chunk goes down and the mirror chunk becomes the primarychunk, disk space allocation re

2-94 IBM Informix OnLine Database Server Administrator’s GuideOnLine Limits for ChunksThe size of each chunk entry on the chunk-tracking page is the l

System Architecture 2-95Reserved PagesReserved PagesThe first 12 pagesof theinitial chunkof therootdbspace are reserved pages.Copies of the first two re

Introduction 5Demonstration DatabaseA Notices appendix contains information about IBM products, services, andfeatures. An index directs you to areas o

2-96 IBM Informix OnLine Database Server Administrator’s GuideReserved PagesThe reserved page checkpoint information is stored in a two-page pair,PAGE

System Architecture 2-97Reserved PagesPAGE_PZEROThe first reserved page in the root dbspace is PAGE_PZERO. Below are listedthe PAGE_PZERO fields and defi

2-98 IBM Informix OnLine Database Server Administrator’s GuideReserved PagesBelow are listedthe checkpoint andlogical log filetracking fields anddefini-t

System Architecture 2-99Reserved PagesPAGE_DBSPThefifthreservedpageintherootdbspaceisPAGE_1DBSP.Thesixthreservedpage, PAGE_2DBSP, is the second page in

2-100 IBM Informix OnLine Database Server Administrator’s GuideReserved PagesPAGE_PCHUNKTheseventhreservedpageintherootdbspaceisPAGE_1PCHUNK.Theeighth

System Architecture 2-101Reserved PagesPAGE_MCHUNKThe ninth reserved page in the root dbspace is PAGE_1MCHUNK. The tenthreserved page, PAGE_2MCHUNK, i

2-102 IBM Informix OnLine Database Server Administrator’s GuideReserved PagesPAGE_ARCHThe eleventhreserved page in theroot dbspace is PAGE_1ARCH. The

System Architecture 2-103Chunk Free-List PageChunk Free-List PageIneverychunk,thepagethatfollowsthelastPreservedpageisthefirstofoneor more chunk free-l

2-104 IBM Informix OnLine Database Server Administrator’s Guidetblspace TblspaceIfnewly freedspace is contiguouswithexistingfreespace,onlythe length o

System Architecture 2-105tblspace Tblspacetblspace Tblspace EntriesEachdata page inthetblspacetblspacedescribes one tblspaceinthedbspaceand is conside

ii IBM Informix OnLine Database Server Administrator’s GuideThis document contains proprietary information of IBM. It is provided under a license agre

6 IBM Informix OnLine Database Server Administrator’s GuideDemonstration DatabaseYou can run the dbaccessdemo5 script again whenever you want a freshd

2-106 IBM Informix OnLine Database Server Administrator’s Guidetblspace TblspaceThe hexadecimal representation of partnum is actually a composite of t

System Architecture 2-107Database Tblspacetblspace Tblspace Bit-Map PageThe first page of the tblspace tblspace, like the first page of any initial exte

2-108 IBM Informix OnLine Database Server Administrator’s GuideCreate a Database: What Happens on DiskEach database tblspace entry includes four compo

System Architecture 2-109Create a Database: What Happens on DiskAllocate Disc SpaceOnLine searches the linked list of chunk free-list maps in the dbsp

2-110 IBM Informix OnLine Database Server Administrator’s GuideOnLine Limits for DatabasesOnLine Limits for DatabasesThe size limits that apply to dat

System Architecture 2-111Create a Table: What Happens on DiskThe paragraphs that follow describe the major events that occur whenOnLine creates a tabl

2-112 IBM Informix OnLine Database Server Administrator’s GuideCreate a Table: What Happens on DiskFigure 2-22 illustrates the pointers within the dis

System Architecture 2-113Create a Temporary Table: What Happens on DiskCreate a Temporary Table: What Happens on DiskAfter the root dbspace exists, us

2-114 IBM Informix OnLine Database Server Administrator’s GuideStructure of an ExtentCleanupExplicit temporary tables are dropped when the OnLine user

System Architecture 2-115Structure of an ExtentPage TypesWithin the extent, individual pages contain different types of data. Extentpages can be separ

Introduction 7IBM Informix OnLineIBM Informix OnLineProduct OverviewThe IBM Informix OnLine database server combines high-availability, onlinetransact

2-116 IBM Informix OnLine Database Server Administrator’s GuideStructure of an ExtentFigure 2-23The initial extentsize for this table is8 pages; the n

System Architecture 2-117Next Extent AllocationNext Extent AllocationWhen an extent fills, OnLine attempts to allocate another extent ofcontiguous disk

2-118 IBM Informix OnLine Database Server Administrator’s GuideNext Extent AllocationIfthediskspaceallocatedforanextextentisphysicallycontiguouswithdi

System Architecture 2-119Next Extent AllocationFigure 2-24When one extentfills, another isautomaticallyallocated. BecauseOnLine considersseveral factor

2-120 IBM Informix OnLine Database Server Administrator’s GuideStructure of a Dbspace PageStructure of a Dbspace PageThe basic unit of OnLine I/O is a

System Architecture 2-121Structure of a Dbspace PagePage HeaderThe page header includes six components: Page identification number (address of the pag

2-122 IBM Informix OnLine Database Server Administrator’s GuideStructure of a Dbspace PageFor example, in a data page, the slot table entry would desc

System Architecture 2-123Data Row Format and RowidData Row Format and RowidOnLine canstore rows thatare longer than apage. OnLine also supports theVAR

2-124 IBM Informix OnLine Database Server Administrator’s GuideData Row Format and RowidThe rowid structure permits the length of the row and its loca

System Architecture 2-125Data Pages and Data Row StorageEventually, a row may outgrow its original storage location. If this occurs, aforward pointer

8 IBM Informix OnLine Database Server Administrator’s GuideDocumentation ConventionsDocumentation ConventionsThis section describes the conventions th

2-126 IBM Informix OnLine Database Server Administrator’s GuideData Pages and Data Row StorageSingle-Page StorageTo minimize retrieval time, rows are

System Architecture 2-127Data Pages and Data Row StorageMultipage StorageWhen OnLine receives a row that is longer than a page, the row is stored inas

2-128 IBM Informix OnLine Database Server Administrator’s GuideData Pages and Data Row StorageFigure 2-29Rows that arelonger than twopages are stored

System Architecture 2-129Data Pages and Data Row StorageStorage of Modified RowsWhen a row is modified, OnLine attempts to return the modified row to its

2-130 IBM Informix OnLine Database Server Administrator’s GuideData Pages and Data Row StorageIf the modified data row is longer than a page, OnLine fir

System Architecture 2-131Data Pages and Data Row StorageIf the leading segment cannot fit into the current location of the row on thehome page, OnLine

2-132 IBM Informix OnLine Database Server Administrator’s GuideData Pages and Data Row StorageFigure 2-31An updated rowthat is longer than afull page

System Architecture 2-133Structure of an Index PagePage CompressionOver time, the free space on a page can become fragmented. When OnLineattempts to s

2-134 IBM Informix OnLine Database Server Administrator’s GuideStructure of an Index PageFigure 2-33 through Figure 2-36 illustrate the progressive cr

System Architecture 2-135Structure of an Index PageThe byte partof the indexkey value isas long asneeded to containthe valueof the index key. If the i

Introduction 9Icon ConventionsIcon ConventionsComment icons identify three types of information, as the following tabledescribes. This information alw

2-136 IBM Informix OnLine Database Server Administrator’s GuideStructure of an Index PageFigure 2-33representsthisinitialphaseofindexstorage.(Refertop

System Architecture 2-137Structure of an Index PageFollowing is an example of some sample data from the stores5:customertable that is included in Figu

2-138 IBM Informix OnLine Database Server Administrator’s GuideStructure of an Index PageFigure 2-34 illustrates the root node page and the two leaf n

System Architecture 2-139Structure of an Index PageWhenthebytevalueisfollowedbyarowidandtwoaddresses,theindexkeyentry indicates that more than one dat

2-140 IBM Informix OnLine Database Server Administrator’s GuideStructure of an Index PageFigure 2-35To aidunderstanding, thisfigure uses lastnames andc

System Architecture 2-141Structure of an Index PageBranch Node PagesThefirstindexbranchnodeis createdaftertherootnodeandatleasttwoleafnodesexist. Regar

2-142 IBM Informix OnLine Database Server Administrator’s GuideStructure of an Index PageFigure 2-36This representationof a complete indexincludes a r

System Architecture 2-143Structure of a Dbspace Bit-Map PageStructure of a Dbspace Bit-Map PageExtentscontainoneormorebit-mappagesthattrackfreepagesin

2-144 IBM Informix OnLine Database Server Administrator’s GuideStructure of a Dbspace Bit-Map PageTwo bits are all that are needed to describe page fu

System Architecture 2-145Blob Storage and the Blob DescriptorBlob Storage and the Blob DescriptorDatarowsthatincludeblobdatadonotincludetheblobdataint

10 IBM Informix OnLine Database Server Administrator’s GuideCommand-Line ConventionsElements That Can Appear on the PathYou might encounter one or mor

2-146 IBM Informix OnLine Database Server Administrator’s GuideStructure of a Dbspace Blob PageBlobs are never modified: only inserted or deleted. When

System Architecture 2-147Structure of a Dbspace Blob PageFor more information about the role of the blob timestamps in maintainingtheconsistencyoftheb

2-148 IBM Informix OnLine Database Server Administrator’s GuideBlobspace Page TypesBlobspace Page TypesEvery blobspace chunk contains three types of p

System Architecture 2-149Structure of a Blobspace BlobpageBlobpageTheblobpagecontainstheblobdata.BlobpagesizeisspecifiedbytheOnLineadministrator who cr

2-150 IBM Informix OnLine Database Server Administrator’s GuideStructure of a Blobspace BlobpageFigure 2-38 illustrates the structure of a blobpage.Th

System Architecture 2-151Structure of a Blobspace BlobpageFigure 2-39 illustrates the different locations of the two pairs of timestampsthat appear on

2-152 IBM Informix OnLine Database Server Administrator’s GuidePhysical LogPhysical LogThe function of the physical log is to maintain a set of “befor

System Architecture 2-153Physical LogBlobspace blobpages do not appear in the physical log because blobs arelogged differently than all other data typ

2-154 IBM Informix OnLine Database Server Administrator’s GuideLogical Log FilesThis same unlikely scenario could occur during the rollback of a long

System Architecture 2-155File RotationForfurtherinformationaboutwhathappensduringa logical logbackupthatmakes this possible, refer to page 4-26. For f

Introduction 11Command-Line ConventionsHow to Read a Command-Line DiagramFigure 1 shows the elements of an OnLine utility command used to unloadOnLine

2-156 IBM Informix OnLine Database Server Administrator’s GuideFile ContentsFile ContentsThe logical log files contain five types of records: SQL data

System Architecture 2-157Number and SizeYou cannot change the size of the logical log files after OnLine disk space isinitialized. If a logical log file

2-158 IBM Informix OnLine Database Server Administrator’s GuideBlobspace LoggingThe duration of a transaction is a key variable that might be beyond y

System Architecture 2-159Long TransactionsTo free a logical log, the log must be backed up to tape and all records withthe logical log must be part of

2-160 IBM Informix OnLine Database Server Administrator’s GuideLong TransactionsThe second long-transaction high-water mark, LTXEHWM, indicates that t

System Architecture 2-161Long TransactionsIf the transactions cannot be rolled back before the logical log fills, OnLineshuts down.If this occurs, youm

3ChapterOperating OnLineIn This Chapter ... 3-5Changing Modes ... 3-6Types of OnLine Modes ... 3-6Offline

3-2 IBM Informix OnLine Database Server Administrator’s GuideLogical Log File Status ... 3-26Logical Log File ID Numbers ... 3

Operating OnLine 3-3Change Pathname of Archive Tape Device ...3-52Change Block Size of Archive Tape Device ...3-55Change Tape Size of Ar

12 IBM Informix OnLine Database Server Administrator’s GuideSample Code ConventionsTo construct a similar command, start at the top left with the comm

3-4 IBM Informix OnLine Database Server Administrator’s GuideModify OnLine Configuration ... 3-87Create a Blobspace... 3-88D

Operating OnLine 3-5In This ChapterOccasionally, administrators conceive of a shortcut that seems like a goodidea. Because of the complexity of OnLine

3-6 IBM Informix OnLine Database Server Administrator’s GuideChanging ModesInthefinalsection,“ModifyOnLineConfiguration,”configuration-changingactionsare

Operating OnLine 3-7Types of OnLine ModesYou can determine the current OnLine mode by executing tbstat. The modeisdisplayedintheheader.Themodealsoappe

3-8 IBM Informix OnLine Database Server Administrator’s GuideFrom Offline to QuiescentFrom Offline to QuiescentWhen OnLine changes from offline to quiesc

Operating OnLine 3-9From Quiescent to OnlineExecute tbinit from the command line to take OnLine from offline to onlinemode.To verifythat OnLineis runni

3-10 IBM Informix OnLine Database Server Administrator’s GuideGracefully from Online to QuiescentGracefully from Online to QuiescentTake OnLine gracef

Operating OnLine 3-11Immediately from Online to QuiescentImmediately from Online to QuiescentTake OnLine immediately from online to quiescent mode whe

3-12 IBM Informix OnLine Database Server Administrator’s GuideFrom Any Mode Immediately to OfflineFrom Any Mode Immediately to OfflineThis is the proper

Operating OnLine 3-13Logical Log AdministrationLogical Log AdministrationThis section discusses configuration and backup of logical log files.For an ove

Introduction 13Sample Code ConventionsTo use this SQL code for a specific product, you must apply the syntax rulesfor that product. For example, if you

3-14 IBM Informix OnLine Database Server Administrator’s GuideExamine Your Logical Log ConfigurationExamine Your Logical Log ConfigurationComplete the t

Operating OnLine 3-15Examine Your Logical Log ConfigurationFreeing the Logical Log FilesThe operator should monitor backed-up logical log files to ensur

3-16 IBM Informix OnLine Database Server Administrator’s GuideExamine Your Logical Log ConfigurationIf you modify the initial configuration values, you

Operating OnLine 3-17Examine Your Logical Log ConfigurationIf the LTAPEDEV and TAPEDEV values are the same, you must plan yourlogicallog file backupstol

3-18 IBM Informix OnLine Database Server Administrator’s GuideChange Pathname of Logical Log Tape DeviceLocation of Logical Log FilesWhen OnLine disk

Operating OnLine 3-19Change Pathname of Logical Log Tape DeviceIfyou are logged inasuserinformix, you canchangethe value ofLTAPEDEVfrom within DB-Moni

3-20 IBM Informix OnLine Database Server Administrator’s GuideChange Pathname of Logical Log Tape DeviceThe host machine where the tape device is atta

Operating OnLine 3-21Change Block Size of Logical Log Tape DeviceFrom the Command LineTo change the value of LTAPEDEV from the command line, use an ed

3-22 IBM Informix OnLine Database Server Administrator’s GuideChange Tape Size of Logical Log Tape DeviceFrom the Command Line1. Use an editor to edit

Operating OnLine 3-23Change Maximum Number of Logical Log FilesFrom the Command Line1. To change the value of LTAPESIZE, use an editor to edit the file

14 IBM Informix OnLine Database Server Administrator’s GuideAdditional DocumentationAdditional DocumentationFor additional information, refer to the f

3-24 IBM Informix OnLine Database Server Administrator’s GuideChange Size of Logical Log FilesFrom DB-Monitor1. From within DB-Monitor, select the Par

Operating OnLine 3-25Change Size of Logical Log FilesFrom DB-Monitor1. From within DB-Monitor, first unload all OnLine data. Refer topage 4-53.2. Selec

3-26 IBM Informix OnLine Database Server Administrator’s GuideLogical Log File StatusLogical Log File StatusYou can display the status of the logical

Operating OnLine 3-27Logical Log File ID NumbersLogical Log File ID NumbersOnLine tracks the logical log files by assigning each free log file a uniquen

3-28 IBM Informix OnLine Database Server Administrator’s GuideAdd a Logical Log FileIn general, log files becomefree after the file has been backedup to

Operating OnLine 3-29Add a Logical Log FileFrom DB-Monitor1. From within DB-Monitor, select the Parameters menu, Add-Logoption to add a logical log fil

3-30 IBM Informix OnLine Database Server Administrator’s GuideDrop a Logical Log FileDrop a Logical Log FileYou can drop a log to increase the amount

Operating OnLine 3-31Move a Logical Log File to Another DbspaceFrom the Command Line1. Fromthecommandline,executethetbparams utilitywiththe-dand-l (lo

3-32 IBM Informix OnLine Database Server Administrator’s GuideMove a Logical Log File to Another DbspaceThe following example illustrates moving six l

Operating OnLine 3-33Change the Logging Status of a DatabaseChange the Logging Status of a DatabaseYou can make any one of the following changes to a

Introduction 15Error Message Files The DB-Access User’s Manual describes how to invoke the utility toaccess, modify, and retrieve information from On

3-34 IBM Informix OnLine Database Server Administrator’s GuideChange the Logging Status of a DatabaseAdding Logging to a DatabaseUnbuffered logging is

Operating OnLine 3-35Change the Logging Status of a DatabaseAdd logging to a database by executing one of these two commands:tbtape -s -B database (bu

3-36 IBM Informix OnLine Database Server Administrator’s GuideBack Up a Logical Log FileYoucanchangetheloggingstatusforanynumberofdatabaseswiththesame

Operating OnLine 3-37Start Continuous Logical Log BackupIf you are logged in as user informix, you can back up a log file from withinDB-Monitoror fromt

3-38 IBM Informix OnLine Database Server Administrator’s GuideEnd Continuous Logical Log BackupWhen you initiate Continuous-Backup, OnLine backs up an

Operating OnLine 3-39Switch to the Next Logical Log FileYou must explicitly request logical log backups (using the DB-Monitor Auto-Backup option or it

3-40 IBM Informix OnLine Database Server Administrator’s GuideFree a Logical Log FileRefertopage 3-15fora discussionabouttheimportanceoffreeingthelogi

Operating OnLine 3-41Free a Logical Log FileStatus AIf a log file is newly added (status A), create a level-0 archive to activate thelog file and make i

3-42 IBM Informix OnLine Database Server Administrator’s GuideIf the Logical Log Backup Cannot CompleteOnLine cannot freethis log. Todo so wouldpermit

Operating OnLine 3-43Archive AdministrationThisprocesscontinues with eachlogfileonTapeA.Whentherestoreprocessencounters the partial log at the end of T

Table of ContentsTable ofContentsIntroductionIn This Introduction ... 3About This Manual ... 3Organization of This Manual

16 IBM Informix OnLine Database Server Administrator’s GuideError Message FilesThemessagesnumbered-1to-100canbeplatform-dependent.Ifthemessagetext for

3-44 IBM Informix OnLine Database Server Administrator’s GuideArchive TypesAn online archive is an archive that is created while OnLine is online andd

Operating OnLine 3-45Archive TypesLevel-1 ArchiveAlevel-1archivecontains a copy of every disk page thathaschangedsincethelastlevel-0archive.Alldiskpag

3-46 IBM Informix OnLine Database Server Administrator’s GuideHow Long Will an Archive Take?How Long Will an Archive Take?Thenumberof variables that y

Operating OnLine 3-47Plan the Archive SchedulePlan the Archive ScheduleEach of the following considerations affects the archive schedule you createfor

3-48 IBM Informix OnLine Database Server Administrator’s GuidePlan the Archive Schedule Size and number of archives. The minimum number of archives i

Operating OnLine 3-49Plan the Archive ScheduleMinimize Archive TimeYou can reduce the number of disk pages that must be copied during anarchivebystori

3-50 IBM Informix OnLine Database Server Administrator’s GuideExamine Your Archive ConfigurationIf the logical log files fill in spite of these precautio

Operating OnLine 3-51Examine Your Archive ConfigurationForfurtherinformationabouttherelationshipofthecurrentconfigurationtothe values in the configuratio

3-52 IBM Informix OnLine Database Server Administrator’s GuideChange Pathname of Archive Tape DeviceIftheTAPEDEV andLTAPEDEVvaluesarethesame,youmust e

Operating OnLine 3-53Change Pathname of Archive Tape DeviceIf you change the pathname to /dev/null, the change proceeds moresmoothly if you make the c

Introduction 17Error Message FilesThe rofferr ScriptUse the rofferr script to format one error message or a range of errormessages forprinting. By def

3-54 IBM Informix OnLine Database Server Administrator’s GuideChange Pathname of Archive Tape DeviceTo specify anarchivetapedeviceon another hostmachi

Operating OnLine 3-55Change Block Size of Archive Tape DeviceFrom the Command Line1. Use an editor to edit the file specified by$INFORMIXDIR/etc/$TBCONF

3-56 IBM Informix OnLine Database Server Administrator’s GuideChange Tape Size of Archive Tape DeviceFrom the Command Line1. To change the value of TA

Operating OnLine 3-57Create an Archive, Any TypeFrom the Command Line1. To change the value of TAPESIZE from the command line, use aneditor to edit th

3-58 IBM Informix OnLine Database Server Administrator’s GuideCreate an Archive, Any TypeAgoodpracticetofollowistolabel archivetapeswiththearchiveleve

Operating OnLine 3-59If the Logical Log Files Fill During an Archive3. Place a write-enabled tape on the tape drive device (defined byTAPEDEV). Put the

3-60 IBM Informix OnLine Database Server Administrator’s GuideIf an Archive Terminates PrematurelyOne Tape DriveIf onlyone tapedevice isavailable toOn

Operating OnLine 3-61Monitor OnLine ActivityMonitor OnLine ActivityMany OnLine structures can be monitored for more than one kind of infor-mation. For

3-62 IBM Informix OnLine Database Server Administrator’s GuideMonitor Archive HistoryFrom the Command LineFrom the command line, execute tbcheck -pr t

Operating OnLine 3-63Monitor Blobs in a BlobspaceMonitor Blobs in a BlobspaceDB-Monitor measures blobspace availability by providing the number ofused

18 IBM Informix OnLine Database Server Administrator’s GuideDocumentation Notes, Release Notes, Machine NotesUsing the PostScript Error Message FilesU

3-64 IBM Informix OnLine Database Server Administrator’s GuideMonitor Blobs in a BlobspaceFrom the Command LineFrom the command line, execute tbstat -

Operating OnLine 3-65Monitor Blobs in a DbspaceThe number of free blobpages is derived from the information stored in theshared-memory version of the

3-66 IBM Informix OnLine Database Server Administrator’s GuideMonitor BuffersMonitor BuffersUse the tbstat -b, -X, and -B options to identify a specifi

Operating OnLine 3-67Monitor Bufferstbstat -BExecute tbstat -B to obtain the following buffer statistics: Address of every regular shared-memory buff

3-68 IBM Informix OnLine Database Server Administrator’s GuideMonitor Buffer-Pool ActivityMonitor Buffer-Pool ActivityMonitor buffer-pool activity to

Operating OnLine 3-69Monitor Checkpointstbstat -RExecute tbstat -R to obtain information about the number of buffers in eachLRU queue and the number a

3-70 IBM Informix OnLine Database Server Administrator’s GuideMonitor ChunksA checkpoint check is performed if the time specified by CKPTINTVL haselaps

Operating OnLine 3-71Monitor ChunksThe second screen display lists the following chunk information for eachdbspace: Chunk ID Chunk pathname and offs

3-72 IBM Informix OnLine Database Server Administrator’s GuideMonitor ChunksExecutetbcheck -pr to obtainthechunkinformationthat is storedinthe rootdbs

Operating OnLine 3-73Monitor Configuration InformationA second solution to chunkfragmentation is tounload and reload the tablesin the chunk.To prevent

Introduction 19Related ReadingRelated ReadingIf you have had no prior experience with database management, you maywant to refer to an introductory tex

3-74 IBM Informix OnLine Database Server Administrator’s GuideMonitor DatabasesReferto page 2-97 foradetaileddescriptionof each fieldintheconfigurationr

Operating OnLine 3-75Monitor DbspacesBecause tbcheck -pc derives its information directly from the tblspace, youdo not need to run the UPDATE STATISTI

3-76 IBM Informix OnLine Database Server Administrator’s GuideMonitor DbspacesThe chunk status flags are defined as follows:From the Command LineFrom th

Operating OnLine 3-77Monitor Disk PagesMonitor Disk PagesUse these options to obtain the specific data row rowid or to view a specificpage in ASCII (and

3-78 IBM Informix OnLine Database Server Administrator’s GuideMonitor ExtentsIfyouprefertouseatblspacenumberandpagenumber,thetblspacenumberis stored a

Operating OnLine 3-79Monitor Index InformationOnesolutiontochunkfragmentationistoclusterthe index of all tables in thechunk using the ALTER TABLE stat

3-80 IBM Informix OnLine Database Server Administrator’s GuideMonitor Logging ActivityExecutethe-pkor-pKoptionsoftbchecktoobtainallpageinformation.(Th

Operating OnLine 3-81Monitor Logging ActivityProcessing stops if OnLine attempts to switch to the next logical log file andfinds that the log file status

3-82 IBM Informix OnLine Database Server Administrator’s GuideMonitor the Message LogExecute tbcheck -pr to obtain detailed logical log file informatio

Operating OnLine 3-83Monitor OnLine ProfileMonitor OnLine ProfileMonitor the OnLine profile to analyze performance over time. The Profilescreenmaintainscu

20 IBM Informix OnLine Database Server Administrator’s GuideIBM Welcomes Your CommentsIBM Welcomes Your CommentsTo help us with future versions of our

3-84 IBM Informix OnLine Database Server Administrator’s GuideMonitor Shared Memory and LatchesMonitor Shared Memory and LatchesMonitor shared memory

Operating OnLine 3-85Monitor TblspacesMonitor TblspacesMonitor tblspaces to determine current space availability and allocation bytable.Forfurtherinfo

3-86 IBM Informix OnLine Database Server Administrator’s GuideMonitor Users and TransactionsMonitor Users and TransactionsMonitor users’ database serv

Operating OnLine 3-87Modify OnLine ConfigurationIf you execute tbstat -u while OnLine is performing fast recovery, severaldatabase server processes mig

3-88 IBM Informix OnLine Database Server Administrator’s GuideCreate a Blobspace Physical log❑ “Change Physical Log Location or Size” on page 3-107

Operating OnLine 3-89Create a BlobspacePreliminary ConsiderationsVerifythatthe DBSPACES valueinthe configuration filewill not be exceeded.DBSPACES refer

3-90 IBM Informix OnLine Database Server Administrator’s GuideCreate a BlobspaceTocontinuetheexample,assumeyourOnLinepagesizeis2KB.Ifyoudecideon a 12-

Operating OnLine 3-91Drop a BlobspaceFrom the Command LineFrom the command line, execute the tbspaces utility with the followingoptions and parameters

3-92 IBM Informix OnLine Database Server Administrator’s GuideChange the Number of Buffers in the PoolIf you are logged in as user informix, you can d

Operating OnLine 3-93Change the Size of Either Log BufferFrom DB-Monitor1. From within DB-Monitor, select the Parameters menu, Shared-Memory option to

1ChapterInstallation and InitialConfigurationIn This Chapter ... 1-5Define Your Starting Point ... 1-6Upgrade an Earlier V

3-94 IBM Informix OnLine Database Server Administrator’s GuideAdd a ChunkFrom DB-Monitor1. From DB-Monitor, select the Parameters menu, Shared-Memoryo

Operating OnLine 3-95Add a ChunkIf you areallocating arawdisk device,youmight needtospecify an offset topreserve track 0 information used by your UNIX

3-96 IBM Informix OnLine Database Server Administrator’s GuideChange the Maximum Number of ChunksFrom the Command LineFrom the command line, execute t

Operating OnLine 3-97Create a DbspaceFrom DB-Monitor1. From within DB-Monitor, select the Parameters menu, Shared-Memory option tochangethe maximum nu

3-98 IBM Informix OnLine Database Server Administrator’s GuideCreate a DbspaceYou can create a dbspace while OnLine is in online mode. The newly added

Operating OnLine 3-99Drop a DbspaceAll options and parameters except -o and -m are required. The followingexample creates a mirrored dbspace dbspce5.

3-100 IBM Informix OnLine Database Server Administrator’s GuideEnforce/Turn Off Residency for This SessionFrom the Command LineFrom the command line,

Operating OnLine 3-101Change the Status of a Mirrored ChunkIf you are logged in as user informix, you can create a dbspace withinDB-Monitoror fromthe

3-102 IBM Informix OnLine Database Server Administrator’s GuideChange the Status of a Mirrored ChunkWhen you initiaterecoveryfor a “down” mirroredchun

Operating OnLine 3-103Change the Status of a Mirrored ChunkFrom DB-Monitor1. FromwithinDB-Monitor, select theDbspacesmenu, Status optiontochange the s

1-2 IBM Informix OnLine Database Server Administrator’s GuideMessage File Guidelines ... 1-28MSGPATH... 1-28CONSOLE ...

3-104 IBM Informix OnLine Database Server Administrator’s GuideEnable MirroringEnable MirroringMirroring activity does not begin until you define mirro

Operating OnLine 3-105Start/End Mirroring in a Blobspace or DbspaceFrom the Command Line1. Fromthecommand line, changethevalue ofMIRROR to1. To do thi

3-106 IBM Informix OnLine Database Server Administrator’s GuideStart/End Mirroring in a Blobspace or DbspaceCreate the mirror chunk on a separate devi

Operating OnLine 3-107Change Physical Log Location or SizeTo start or end mirroring1. Select the Dbspaces menu, Mirror option.Every OnLine blobspace a

3-108 IBM Informix OnLine Database Server Administrator’s GuideChange Physical Log Location or SizeCreate a level-0 archive immediately after you rein

Operating OnLine 3-109Change the Checkpoint IntervalFrom the Command LineFrom the command line, execute the tbparams utility with the followingoptions

3-110 IBM Informix OnLine Database Server Administrator’s GuideChange the Destination of Console MessagesTo change the value of CKPTINTVL from the com

Operating OnLine 3-111Change the Maximum Number of Dbspaces4. Whenasecondpromptappearstoconfirmthatyouwanttocontinue(to initialize OnLine disk space an

3-112 IBM Informix OnLine Database Server Administrator’s GuideChange the Maximum Number of LocksFrom the Command Line1. To change the value of DBSPAC

Operating OnLine 3-113Change the Maximum Number of TblspacesChange the Maximum Number of TblspacesThe maximum number of active tblspaces permitted by

Installation and Initial Configuration 1-3OnLine Disk Space Allocation ...1-40Allocate Raw Disk Space or Cooked Files?...1-40How Much

3-114 IBM Informix OnLine Database Server Administrator’s GuideChange the Maximum Number of UsersChange the Maximum Number of UsersUsers,inthiscontext

Operating OnLine 3-115Change the Number of Page CleanersFrom the Command Line1. To change the value of USERS from the command line, use an editorto ed

3-116 IBM Informix OnLine Database Server Administrator’s GuideThings to AvoidFrom the Command Line1. To change the value of CLEANERS from the command

4ChapterData Consistency, Recovery,and MigrationIn This Chapter ... 4-5Consistency Checking... 4-6Using the tbcheck Co

4-2 IBM Informix OnLine Database Server Administrator’s GuideWhat Happens During Logical Log Backup ... 4-26Ready LTAPEDEV ... 4

Data Consistency, Recovery, and Migration 4-3Initiate Data Restore from Offline Mode ...4-49Mount Level-0 Archive Tape ...4-49Verif

4-4 IBM Informix OnLine Database Server Administrator’s Guide

Data Consistency, Recovery, and Migration 4-5In This ChapterSeveral OnLine tasks that are critical to long-term operation are performedautomatically.

4-6 IBM Informix OnLine Database Server Administrator’s GuideConsistency CheckingConsistency CheckingOnLine 5 contains a page-level layer of checks th

Data Consistency, Recovery, and Migration 4-7Using the tbcheck Commandstbcheck -crExecute tbcheck -cr to validate the OnLine reserved pages that resid

1-4 IBM Informix OnLine Database Server Administrator’s Guide

4-8 IBM Informix OnLine Database Server Administrator’s GuideUsing the OnLine Message Logtbcheck -cIExecutetbcheck-cIforeachdatabasetovalidateindexeso

Data Consistency, Recovery, and Migration 4-9Setting Consistency-Checking VariablesThe problem text briefly describes the type of consistency error. Th

4-10 IBM Informix OnLine Database Server Administrator’s GuideSetting Consistency-Checking Variables(Acoredumpisanimageofthedatabaseserverprocessinmem

Data Consistency, Recovery, and Migration 4-11Setting Consistency-Checking VariablesDUMPCORESet the DUMPCORE environmental variable as an alternative

4-12 IBM Informix OnLine Database Server Administrator’s GuideRecovering from CorruptionSet the DUMPSHMEM environment variable at the system prompt or

Data Consistency, Recovery, and Migration 4-13Recovering from CorruptionOnLine alerts the user and administrator to possible corruption through thefol

4-14 IBM Informix OnLine Database Server Administrator’s GuideMirroringIfthe downchunk ismirrored,OnLinecontinues to operateusingthe mirrorchunk. Use

Data Consistency, Recovery, and Migration 4-15BeginningRecover a mirrored chunk through the DB-Monitor Dbspaces menu, Statusoption or through the tbsp

4-16 IBM Informix OnLine Database Server Administrator’s GuideProcessingThe reason for the delay is to ensure a proper restore. The level-0 archivecop

Data Consistency, Recovery, and Migration 4-17RecoveryImportant: If OnLine detects an I/O error on a chunk that is not mirrored, OnLinemarks the chunk

Installation and Initial Configuration 1-5In This ChapterThis chapter describes how to get started administering your IBM InformixOnLine environment.Y

4-18 IBM Informix OnLine Database Server Administrator’s GuideOnLine Logging OverviewOnLine Logging OverviewThelogicallogfilesareatthecenterofallOnLine

Data Consistency, Recovery, and Migration 4-19Dbspace LoggingDbspace LoggingOnLine logs dbspacedata operationsin six steps,illustrated inFigure 4-1onp

4-20 IBM Informix OnLine Database Server Administrator’s GuideDbspace LoggingFigure 4-1OnLine logsdbspaceoperations in sixsteps.OnLine disk1243356Data

Data Consistency, Recovery, and Migration 4-21Dbspace LoggingIn general, an insert or an update begins when a database server processrequests a row. O

4-22 IBM Informix OnLine Database Server Administrator’s GuideBlobspace LoggingBlobspace LoggingOnLine logs blobspace data in three steps, illustrated

Data Consistency, Recovery, and Migration 4-23Blobspace LoggingFigure 4-2OnLine logsblobspaceoperations in threesteps.OnLinesharedmemoryOnLine diskBlo

4-24 IBM Informix OnLine Database Server Administrator’s GuideBlobspace LoggingOperations LoggingOnLine does not copy blobspace data to the logical lo

Data Consistency, Recovery, and Migration 4-25Blobspace LoggingOnLine allocates and deallocates blobpages via the blobspace free-mappages. (Refer to p

4-26 IBM Informix OnLine Database Server Administrator’s GuideWhat Happens During Logical Log BackupFor further information about what happens during

Data Consistency, Recovery, and Migration 4-27Ready LTAPEDEVReady LTAPEDEVWhenyourequestalogicallog backup,youarepromptedtomountatapeonthe tape device

iv IBM Informix OnLine Database Server Administrator’s GuideChapter 1 Installation and Initial ConfigurationIn This Chapter ... 1-5Defin

1-6 IBM Informix OnLine Database Server Administrator’s GuideDefine Your Starting PointDefine Your Starting PointThissectiondirectsyoutothestartingpoint

4-28 IBM Informix OnLine Database Server Administrator’s GuidePlace Log Header on TapeEach blobpage that was allocated during the time that this log fi

Data Consistency, Recovery, and Migration 4-29Write Log Records to TapeWrite Log Records to TapeThe tbtape process begins copying each page in the log

4-30 IBM Informix OnLine Database Server Administrator’s GuideWrite Trailer PageIf the backup was initiated explicitly through tbtape -a or Auto-Backu

Data Consistency, Recovery, and Migration 4-31Read Archive History Information5. tbtape forces a checkpoint.6. tbtape synchronizes activity with the t

4-32 IBM Informix OnLine Database Server Administrator’s GuideVerify the Archive LevelVerify the Archive LevelAs part of the archive request, you spec

Data Consistency, Recovery, and Migration 4-33Synchronize tbtape and tbinit Activities(It is likely that some transactions are ongoing during an onlin

4-34 IBM Informix OnLine Database Server Administrator’s GuideSynchronize tbtape and tbinit ActivitiesThe answer is that tbtape and tbinit synchronize

Data Consistency, Recovery, and Migration 4-35Write Tape Header PageArchive blobpagesThe second task facing tbtape is to prevent database server proce

4-36 IBM Informix OnLine Database Server Administrator’s GuideArchive Reserved PagesWith this action, the root dbspace reserved pages receive acknowle

Data Consistency, Recovery, and Migration 4-37Determine Archive CriteriaDetermine Archive CriteriaAs tbtape reads each disk page, it applies a set of

Installation and Initial Configuration 1-7Upgrade an Earlier Version of OnLineIf you are installing OnLine 5.x and plan to run it on the same host mac

4-38 IBM Informix OnLine Database Server Administrator’s GuideArchive Disk Pages That Meet CriteriaA level-1 archive directs tbtape to consider a narr

Data Consistency, Recovery, and Migration 4-39Fast RecoveryFast RecoveryFast recovery is an automatic, fault tolerance feature that OnLine executesany

4-40 IBM Informix OnLine Database Server Administrator’s GuideFast Recovery and LoggingThe aim of fast recovery is to return OnLine to a consistent st

Data Consistency, Recovery, and Migration 4-41Step 1: Checkpoint ConditionStep 1: Checkpoint ConditionThe first step, returning all disk pages to their

4-42 IBM Informix OnLine Database Server Administrator’s GuideStep 2: Find Checkpoint Record in Logical LogOnce this information is read, it also iden

Data Consistency, Recovery, and Migration 4-43Step 3: Roll Forward Log RecordsStep 3: Roll Forward Log RecordsThe third step in fast recovery is to ro

4-44 IBM Informix OnLine Database Server Administrator’s GuideStep 4: Roll Back Incomplete TransactionsStep 4: Roll Back Incomplete TransactionsThe fin

Data Consistency, Recovery, and Migration 4-45Data Restore: When Should You Do It?Data Restore: When Should You Do It?Three types of situations could

4-46 IBM Informix OnLine Database Server Administrator’s GuideSteps That Occur During a Data Restore7. Mount the first level-0 archive tape on TAPEDEV.

Data Consistency, Recovery, and Migration 4-47Gather All Tapes Needed for RestoreGather All Tapes Needed for RestoreTo restore OnLine, you need all ar

1-8 IBM Informix OnLine Database Server Administrator’s GuideUpgrade an Earlier Version of OnLineCreate a Level-0 ArchiveAsk all users to exit their a

4-48 IBM Informix OnLine Database Server Administrator’s GuideVerify OnLine ConfigurationLogicallogs files that remainondiskand which havenotyetbeenback

Data Consistency, Recovery, and Migration 4-49Initiate Data Restore from Offline ModeVerify that all raw devices that have been in use since the level-

4-50 IBM Informix OnLine Database Server Administrator’s GuideVerify Current ConfigurationVerify Current ConfigurationAs its first task, tbtape reads the

Data Consistency, Recovery, and Migration 4-51Write Each Archive Page to DiskWrite Each Archive Page to DiskIt might be that your configuration defines

4-52 IBM Informix OnLine Database Server Administrator’s GuideOnLine Is QuiescentMount thecorrect tape on LTAPEDEV. Verify that the tape drive is onli

Data Consistency, Recovery, and Migration 4-53Database and Table MigrationThe correct method for you depends on your processing environment andwhatyou

4-54 IBM Informix OnLine Database Server Administrator’s GuideDescription of Migration MethodsDescription of Migration MethodsThis section provides an

Data Consistency, Recovery, and Migration 4-55Description of Migration Methodsdbexport/dbimportThe dbexport and dbimport utility pair operates only on

4-56 IBM Informix OnLine Database Server Administrator’s GuideDescription of Migration MethodsFigure 4-10Description ofmigration methods}}}}}}UNLOAD/d

Data Consistency, Recovery, and Migration 4-57Which Migration Method Is Best for You?Which Migration Method Is Best for You?Eachofthemigrationmethodsi

Installation and Initial Configuration 1-9Upgrade an Earlier Version of OnLineRun tbcheckVerifythe integrity oftheupgraded 5.x databasesbefore you con

4-58 IBM Informix OnLine Database Server Administrator’s GuideWhich Migration Method Is Best for You?Figure 4-12Seconddecision treesummarizing thechoi

Data Consistency, Recovery, and Migration 4-59Which Migration Method Is Best for You?InthechoicebetweenLOADordbload,thetrade-offisease-of-useandspeedv

4-60 IBM Informix OnLine Database Server Administrator’s GuideUsing UNLOAD with LOAD or dbloadUsing UNLOAD with LOAD or dbloadThissection describes th

Data Consistency, Recovery, and Migration 4-61Using UNLOAD with LOAD or dbloadCreate and Edit the Schema File FirstUse dbschema to create a schema file

4-62 IBM Informix OnLine Database Server Administrator’s GuideUsing dbexport and dbimportUse LOAD or dbload to Populate the TablesIf you plan to use t

Data Consistency, Recovery, and Migration 4-63Using tbunload and tbloadThe.sql file does notcontainall table informationavailable fromtheexistingdataba

4-64 IBM Informix OnLine Database Server Administrator’s GuideUsing tbunload and tbloadtbunloadThe tbunload utility can unload data more quickly than

Data Consistency, Recovery, and Migration 4-65Migrating Data from OnLine to SE tbload createsadatabase without logging;youmust initiate loggingafter

4-66 IBM Informix OnLine Database Server Administrator’s GuideMigrating Data from SE to OnLineFormoreinformationaboutthedifferencesbetweenthetwodataba

Formoreinformationaboutthedifferencesbetweenthetwodatabaseserversand their interpretation of SQL, refer to IBM Informix Guide to SQL: Reference.

1-10 IBM Informix OnLine Database Server Administrator’s GuideOverview of OnLine Installation StepsOverview of OnLine Installation StepsInstallingOnLi

4-68 IBM Informix OnLine Database Server Administrator’s GuideMigrating Data from SE to OnLine

5ChapterHow to Improve PerformanceIn This Chapter ... 5-3Disk Layout ... 5-4Optimize Blobspace Blobpage Size ...

5-2 IBM Informix OnLine Database Server Administrator’s GuideCheckpoint Frequency... 5-20Performance Tradeoffs ... 5-20How

How to Improve Performance 5-3In This ChapterWith each OnLine release, Informix engineers incorporate new code thatincreases processing efficiency, red

5-4 IBM Informix OnLine Database Server Administrator’s GuideDisk LayoutPerformance-tuning issues are addressed as six topics in this chapter: When i

How to Improve Performance 5-5Optimize Blobspace Blobpage SizeOptimize Blobspace Blobpage SizeFamiliarize yourself with the OnLine approach to blobspa

5-6 IBM Informix OnLine Database Server Administrator’s Guidetbcheck -pB and tbcheck -pe Utility CommandsRefer to page 7-38 for tbcheck -pB and tbchec

How to Improve Performance 5-7Blobpage Average FullnessThe example output indicates that four blobs are stored as part of the tablesriram.catalog. Two

5-8 IBM Informix OnLine Database Server Administrator’s GuideApply Effective CriteriaApply Effective CriteriaLooking at the efficiency information for

How to Improve Performance 5-9Eliminate User-Created Resource Bottlenecks Do not perform mass updates on frequently accessed tables.During an update,

Installation and Initial Configuration 1-11OnLine Configuration FilesOnLine Configuration FilesYou are notlimited to just one configuration file. You can

5-10 IBM Informix OnLine Database Server Administrator’s GuideWhen Is Tuning Needed?When Is Tuning Needed?As administrator, attempt to follow as close

How to Improve Performance 5-11ovtbls, ovlock, ovuser, and ovbuff FieldsRefer to page 5-17 for more details about using these fields to modify thevalue

5-12 IBM Informix OnLine Database Server Administrator’s GuideBufsize Pages/IO FieldsBuffer size and the amount of I/O per write are reported by the D

How to Improve Performance 5-13Shared-Memory BuffersShared-Memory BuffersIn general, you want to allocate shared-memory buffers to OnLine until youno

5-14 IBM Informix OnLine Database Server Administrator’s GuideShared-Memory ResourcesImportant: Low caching percentages might reflect improperly tuned

How to Improve Performance 5-15How Is Tuning Done?How Is Tuning Done?You can increase the number of shared-memory resources by increasing thevalueofTB

5-16 IBM Informix OnLine Database Server Administrator’s GuideHow Is Tuning Done?How Is Tuning Done?If the value of Pages/IO is 75 percent or more of

How to Improve Performance 5-17Page-Cleaner ParametersPage-Cleaner ParametersIn the discussion of page-cleaning tuning, it is especially true that you

5-18 IBM Informix OnLine Database Server Administrator’s GuideEfficient Page CleaningYou should still avoid foreground writes and LRU writes, displayed

How to Improve Performance 5-19How Is Tuning Done?How Is Tuning Done?If the cached-read percentage is lower than 95 percent, you might be able toimpro

1-12 IBM Informix OnLine Database Server Administrator’s GuideOnLine Configuration FilesIf you modify the configuration file while OnLine is online, you

5-20 IBM Informix OnLine Database Server Administrator’s GuideCheckpoint FrequencyCheckpoint FrequencyFamiliarize yourself with the definition ofa chec

How to Improve Performance 5-21How Is Tuning Done?How Is Tuning Done?Thefirststepintuningisto determine the cause of frequentcheckpoints.Arethe checkpo

5-22 IBM Informix OnLine Database Server Administrator’s GuidePsort Parallel-Process Sorting PackagePsort Parallel-Process Sorting PackagePsortisasort

How to Improve Performance 5-23Tuning PsortTuning PsortIf PSORT_NPROCS is set to 0, Psort uses three as the default number ofprocesses for the sort.Wh

5-24 IBM Informix OnLine Database Server Administrator’s GuidePsort and Shared MemoryPsort and Shared MemoryEach parallel sort uses one UNIX shared-me

How to Improve Performance 5-25SPINCNT Configuration ParameterThe number of times that a user process spins and tests is specified by theconfiguration pa

6ChapterDB-Monitor ScreensIn This Chapter ... 6-3Main Menu ... 6-4Status Menu ... 6-5Parameters Men

6-2 IBM Informix OnLine Database Server Administrator’s Guide

DB-Monitor Screens 6-3In This ChapterThis chapter serves as a reference for the DB-Monitor screens. You can use itto quickly determine the purpose and

Installation and Initial Configuration 1-13Contents of tbconfig.stdContents of tbconfig.stdThe tbconfig.std file contains all OnLine configuration paramete

6-4 IBM Informix OnLine Database Server Administrator’s GuideMain MenuMain MenuMenuItemStatus Parameters Dbspaces ModeForce-CkptArchive Logical-Logs E

DB-Monitor Screens 6-5Status MenuStatus MenuOption Description See page...ProfileUse the Profile option to display OnLine perfor-mance statistics.3-83U

6-6 IBM Informix OnLine Database Server Administrator’s GuideParameters MenuParameters MenuOption Description See page...Initialize Use the Initialize

DB-Monitor Screens 6-7Dbspaces MenuDbspaces MenuOption Description See page...Create Use the Create option to create a dbspace.3-97BLOBSpace Use the B

6-8 IBM Informix OnLine Database Server Administrator’s GuideMode MenuMode MenuOption Description See page...Startup Use the Startup option to initial

DB-Monitor Screens 6-9Force-Ckpt OptionForce-Ckpt OptionDescription See page...Use the Force-Ckpt option to see the time of the most recent check-poin

6-10 IBM Informix OnLine Database Server Administrator’s GuideArchive MenuArchive MenuOption Description See page...Create Use the Create option to cr

DB-Monitor Screens 6-11Logical-Logs MenuLogical-Logs MenuOption Description See page...Auto-Backup UsetheAuto-BackupoptiontodirectOnLine tobackup allf

7ChapterUtilitiesIn This Chapter ... 7-5dbexport: Unload a Database and Schema File ... 7-5Syntax ... 7-6Des

1-14 IBM Informix OnLine Database Server Administrator’s GuideContents of tbconfig.stdDBSPACES specifies the maximum number of dbspaces supported by thi

7-2 IBM Informix OnLine Database Server Administrator’s Guidetbcheck: Check, Repair, or Display... 7-36Syntax ... 7-38Op

Utilities 7-3Interpreting tblog Output ...7-55Record Types ...7-56Record Contents...7-57tbmode: Mode and S

7-4 IBM Informix OnLine Database Server Administrator’s Guide-F Option... 7-87-k Option... 7-88-l Option ...

Utilities 7-5In This ChapterThis chapter describes the OnLine utilities that allow you to execute admin-istrative tasks directly from the shell prompt

7-6 IBM Informix OnLine Database Server Administrator’s GuideSyntaxThe SQL statements contained in the dbexport schema file do not contain allavailable

Utilities 7-7Destination OptionsYoucanusetheOnLinesyntaxdatabase@dbservernametospecifythedatabase.Specifying a database server name allows you to choo

7-8 IBM Informix OnLine Database Server Administrator’s GuideDestination OptionsIfyoudonotspecifyadestinationforthedataandschemafiles,thedirectorydatab

Utilities 7-9Contents of the Schema FileContents of the Schema FileThe .sql file contains the SQL statements needed to re-create the exporteddatabase,

7-10 IBM Informix OnLine Database Server Administrator’s Guidedbimport: Create a DatabaseThestatements in theASCII schemafilethat createtables, views,

Utilities 7-11SyntaxIf you are loading a database from IBM Informix SE into an OnLineenvironment, check that you set the SQLEXEC environment variable

Installation and Initial Configuration 1-15Contents of tbconfig.stdLRUS specifies the number of LRU (least-recently used) queues. The LRUqueues manage t

7-12 IBM Informix OnLine Database Server Administrator’s GuideInput File Location OptionsYou can cancel dbimport at any time by pressing the Interrupt

Utilities 7-13Input File Location OptionsYou cannot use the -f option unless it was used when the schema file wasexported with the dbexport program. If

7-14 IBM Informix OnLine Database Server Administrator’s GuideCreate OptionsCreate OptionsA database that is ANSI-compliant uses unbuffered logging. I

Utilities 7-15dbload: Load Data from a Command FileThenextcommandimportsthestores5databasefromtapeintotheaucklanddbspace. The database is created with

7-16 IBM Informix OnLine Database Server Administrator’s GuideSyntaxThe dbload syntax and use information begins in the next section. Thedbload comman

Utilities 7-17SyntaxTheerrorlogfilespecifiedbythe-lflagstoresanyinputfilerowsthatdbloadcannot insert into the database, as well as diagnostic information.

7-18 IBM Informix OnLine Database Server Administrator’s GuideCommand-File Syntax CheckCommand-File Syntax CheckThe -s option performs a syntax check

Utilities 7-19Batch SizeThe -i option instructs dbload to read and ignore the specified number ofNEWLINE charactersintheinputfilebeforeitbeginsprocessin

7-20 IBM Informix OnLine Database Server Administrator’s GuideBad-Row LimitsBad-Row LimitsIfyouset-enumber errorsreadtoaninteger,dbloadterminateswheni

Utilities 7-21How to Create a Command FileHow to Create a Command FileBeforeyouuse dbload,youfirstcreateanASCIIcommand file thatnamestheinput data files

Table of Contents vChapter 2 System ArchitectureIn This Chapter ... 2-7Initialization ... 2-7Initialization Commands ..

1-16 IBM Informix OnLine Database Server Administrator’s GuideContents of tbconfig.stdMIRROR specifies whether OnLine blobspace and dbspace mirroring is

7-22 IBM Informix OnLine Database Server Administrator’s GuideHow to Create a Command FileYou can combine both forms of the FILE statement in a single

Utilities 7-23How to Create a Command FileTwo consecutive delimiters define a null field. As a precaution, you mightwish to place a delimiter immediatel

7-24 IBM Informix OnLine Database Server Administrator’s GuideHow to Create a Command FileThe restrictions dbload imposes on the VALUES clause value l

Utilities 7-25How to Create a Command FileThe FILE statement describes the stock.unl data rows as composed of sixfields, each separated by a vertical b

7-26 IBM Informix OnLine Database Server Administrator’s GuideHow to Create a Command FileIn this example, the VALUES clause uses the automatically as

Utilities 7-27How to Create a Command FileFields in the input file are padded with blanks (represented by + in thefollowing example) to create data row

7-28 IBM Informix OnLine Database Server Administrator’s GuideHow to Create a Command FileThe same character position can be repeated in a data field d

Utilities 7-29How to Create a Command FileThe restrictions dbload imposes on the VALUES clause value list affect onlydata types DATE, DATETIME, andINT

7-30 IBM Informix OnLine Database Server Administrator’s GuideHow to Create a Command FileThe FILE statement defines six data fields from the cust_loc_d

Utilities 7-31How to Create a Command FileThe following data rows would be inserted into the cust_address table:Since the second column in cust_addres

Installation and Initial Configuration 1-17Contents of tbconfig.stdROOTPATH specifies the pathname of the chunk where the root dbspaceresides.Informix r

7-32 IBM Informix OnLine Database Server Administrator’s Guidedbschema: Output SQL Statementsdbschema: Output SQL StatementsUse the dbschema utility t

Utilities 7-33Include SynonymsAll SERIAL fields included in CREATE TABLE statements displayed bydbschema have a starting value of 1, regardless of thei

7-34 IBM Informix OnLine Database Server Administrator’s GuideInclude PrivilegesInclude PrivilegesIfyouspecifyall foruser, dbschema outputsGRANT state

Utilities 7-35Specify a Table, View, or ProcedureSpecify a Table, View, or ProcedureIf you specify all for the name of the procedure, dbschema display

7-36 IBM Informix OnLine Database Server Administrator’s Guidetbcheck: Check, Repair, or Displaytbcheck: Check, Repair, or DisplayDepending on the opt

Utilities 7-37tbcheck: Check, Repair, or DisplayIndex (keys plus rowids) -cI -cI -y, -pK -y -pKIndex (leaf key values) -pl -y -plIndex (leaf keys plus

7-38 IBM Informix OnLine Database Server Administrator’s GuideSyntaxSyntaxtbcheck-ce-cr-pe-pr-pc-cc-cd-cD-ci-c-pB-pk-pK-pl-pL-pt-pT-pdrowid-pprowidtbl

Utilities 7-39Option DescriptionsOption DescriptionsYou cannot combine tbcheck option flags except as described in theparagraphs that follow.No Options

7-40 IBM Informix OnLine Database Server Administrator’s GuideOption DescriptionsTo check the tables, tbcheck compares each system catalog table to it

Utilities 7-41Option DescriptionsIf inconsistencies are detected and OnLine is in quiescent mode, you areprompted for confirmation to repair theproblem

1-18 IBM Informix OnLine Database Server Administrator’s GuideContents of tbconfig.stdUSERS specifies the maximum number of OnLine user processes that c

7-42 IBM Informix OnLine Database Server Administrator’s GuideOption Descriptions-pB OptionThe -pB option displays statistics that describe the averag

Utilities 7-43Option Descriptions-pe OptionThe -pe option performs the same checks as the -ce option. In addition, -pedisplaysthechunkandtblspaceexten

7-44 IBM Informix OnLine Database Server Administrator’s GuideOption DescriptionsUse the -pD option to obtain the rowid. Refer to page 2-104 for more

Utilities 7-45tbinit: Initialize OnLineOutput for both -pt and -pT contains listings for “Number of pages used”and “Number of data pages.” The values

7-46 IBM Informix OnLine Database Server Administrator’s GuideSyntaxSyntaxNo OptionsIf you execute tbinit without options, OnLine is left in online mo

Utilities 7-47tbload: Create a Database or Table-p OptionThe -p option directs the tbinit daemon not to search for (and delete)temporary tables left b

7-48 IBM Informix OnLine Database Server Administrator’s GuideSyntaxIf youare loading a tablethat contains blobs stored in a blobspace, a promptasks y

Utilities 7-49Specify Tape ParametersIf you do not specify any tape parameter options, tbload uses the archivetape parameters bydefault. Thetape devic

7-50 IBM Informix OnLine Database Server Administrator’s GuideCreate OptionsThe host machine where the tape device is attached must permit userinformi

Utilities 7-51tblog: Display Logical Log Contentstblog: Display Logical Log ContentsThetblogutilitydisplaysthecontentsofanOnLinelogicallogfile.Thetblog

Installation and Initial Configuration 1-19Contents of tbconfig.stdTAPEDEV /dev/tapedev# Archive tape device pathnameTAPEBLK 16 # Archive tape block si

7-52 IBM Informix OnLine Database Server Administrator’s GuideLog-Record Read FiltersIn addition to the header, you can direct tblog to display the fo

Utilities 7-53Log-Record Read Filters-d OptionIfyoudonotusethe-doption,tblogreadsthelogicallogfilesstoredondisk,starting with the logical log file with

7-54 IBM Informix OnLine Database Server Administrator’s GuideLog-Record Display FiltersLog-Record Display FiltersYou can combine options with any oth

Utilities 7-55Interpreting tblog OutputInterpreting tblog OutputThetblogutilitydisplaystheheaderofeachlogicallogrecord.Dependingontherecordtype,additi

7-56 IBM Informix OnLine Database Server Administrator’s GuideInterpreting tblog OutputRecord TypesIn addition to the six columns that display for eve

Utilities 7-57Interpreting tblog Output Remainder page update Before update record After update recordRecord ContentsThe table below lists tblog re

7-58 IBM Informix OnLine Database Server Administrator’s GuideInterpreting tblog OutputBFRMAP blob free map change tblspace idbpagenostatuslog idprevp

Utilities 7-59Interpreting tblog OutputBTSHUFFL shuffle B+ tree nodes tblspace idparent logical pageleft logical pageright logical pageleft slotleft ro

7-60 IBM Informix OnLine Database Server Administrator’s GuideInterpreting tblog OutputCKPOINT checkpoint max usersnumber ofactive transactionsdecimal

Utilities 7-61Interpreting tblog OutputERASE drop tblspace tblspace id hexadecimalHDELETE home row delete tblspace idrowidslotlenhexadecimalhexadecima

1-20 IBM Informix OnLine Database Server Administrator’s GuideSet Up Your Initial Configuration(multiprocessor-machine default is 300)STAGEBLOB # INFOR

7-62 IBM Informix OnLine Database Server Administrator’s GuideInterpreting tblog OutputPBINSERT tblspace blob pageinsertbpagenotblspace idrowidslotlen

Utilities 7-63Interpreting tblog OutputRUPBEF remainder pageupdate, before imagetblspace idrowidslotlenhexadecimalhexadecimaldecimalTABLOCKS list of l

7-64 IBM Informix OnLine Database Server Administrator’s Guidetbmode: Mode and Shared-Memory Changestbmode: Mode and Shared-Memory ChangesThe flags tha

Utilities 7-65SyntaxSyntax-y automatically responds “yes” to all prompts.tbmode-yForcea Checkpointpage 7-67Change Shared-Memory Residencypage 7-68Swit

7-66 IBM Informix OnLine Database Server Administrator’s GuideChange OnLine ModeChange OnLine Mode-k OptionThe -k option is equivalenttothe DB-Monitor

Utilities 7-67Force a Checkpoint-s OptionThe -s option is equivalent to the DB-Monitor Graceful-Shutdown option.Onceyouexecutethe-s option,youcannotca

7-68 IBM Informix OnLine Database Server Administrator’s GuideChange Shared-Memory ResidencyChange Shared-Memory ResidencyAny change you make using tb

Utilities 7-69Kill an OnLine Server ProcessKill an OnLine Server ProcessWarning: Do not kill an OnLine database server process that is in a critical s

7-70 IBM Informix OnLine Database Server Administrator’s Guidetbparams: Modify Log Configuration Parameterstbparams: Modify Log Configuration Parameters

Utilities 7-71Drop a Logical Log FileYou cannot add a log file during an archive (quiescent or online). The newlyadded log file or files retain a status

Installation and Initial Configuration 1-21Root Dbspace Configuration GuidelinesRoot Dbspace Configuration GuidelinesThe root dbspace, like all dbspaces

7-72 IBM Informix OnLine Database Server Administrator’s GuideChange Physical Log ParametersChange Physical Log ParametersThe space allocatedfor theph

Utilities 7-73tbspaces: Modify Blobspaces or Dbspacestbspaces: Modify Blobspaces or DbspacesUse tbspaces to perform the following modifications: Creat

7-74 IBM Informix OnLine Database Server Administrator’s GuideCreate a Blobspace or DbspaceCreate a Blobspace or DbspaceRefer to page 3-88 for more de

Utilities 7-75Drop a Blobspace or DbspaceDrop a Blobspace or DbspaceThe blobspace or dbspace you intend to drop must be unused. It is not suffi-cient f

7-76 IBM Informix OnLine Database Server Administrator’s GuideAdd a ChunkAdd a ChunkRefer to page 3-94 for more details to consider when you are addin

Utilities 7-77Change Chunk StatusChange Chunk StatusYou can only change the status of a chunk in a mirrored pair. Refer topage 3-101for moredetailsto

7-78 IBM Informix OnLine Database Server Administrator’s Guidetbstat: Monitor OnLine Operationtbstat: Monitor OnLine OperationThetbstatutilityreadssha

Utilities 7-79tbstat: Monitor OnLine OperationShared-memory segment (save it to a file) -oSummary of user-oriented (lowercase) options -aTblspaces, act

7-80 IBM Informix OnLine Database Server Administrator’s GuideSyntaxSyntax1secondsa1b1B1c1d1D1F1k1l1m1p1P1r1R1s1t1u1X1z1filename_destfilename_sourceo--

Utilities 7-81SyntaxUse the filename_source parameter with other option flags to derive therequested tbstat statistics from the shared-memory segment co

1-22 IBM Informix OnLine Database Server Administrator’s GuideRoot Dbspace Configuration GuidelinesROOTPATHThe ROOTPATH parameter specifies the pathname

7-82 IBM Informix OnLine Database Server Administrator’s GuideOption DescriptionsAn example header follows:RSAM Version 5.0--On-Line--Up 15:11:41--368

Utilities 7-83Option DescriptionsThe number of modified buffers, the number of total buffers available, thenumber of hash buckets available, and the si

7-84 IBM Informix OnLine Database Server Administrator’s GuideOption Descriptions-B OptionUse the -B option to obtain information about all OnLine buf

Utilities 7-85Option DescriptionsThe number of active blobspaces and dbspaces and the total number ofexisting blobspaces and dbspaces are listed. The

7-86 IBM Informix OnLine Database Server Administrator’s GuideOption DescriptionsThe number of active chunks and the number of existing chunks are lis

Utilities 7-87Option Descriptions-F OptionUse the -F option to display account for each type of write performed whena page was flushed to disk. You ca

7-88 IBM Informix OnLine Database Server Administrator’s GuideOption Descriptions-k OptionUsethe-koptiontodisplayinformation about activelocks.You can

Utilities 7-89Option DescriptionsThemaximumnumberoflocksavailableisspecifiedasLOCKS intheOnLineconfiguration file.-l OptionUse the-l optionto displayinfo

7-90 IBM Informix OnLine Database Server Administrator’s GuideOption DescriptionsThe second section of the tbstat -l display describes the logical log

Utilities 7-91Option DescriptionsThe following fields are repeated for each logical log file:-m OptionUse the -m option to display the 20 most-recent li

Installation and Initial Configuration 1-23Root Dbspace Configuration GuidelinesROOTSIZEROOTSIZEspecifiesthesizeoftheinitialchunkoftherootdbspace,expres

7-92 IBM Informix OnLine Database Server Administrator’s GuideOption Descriptions-p OptionUse the -p option to display profile counts.The first portion

Utilities 7-93Option DescriptionsThe next portion of the -p display tabulates the number of times differentISAM callswereexecuted.The calls occur atth

7-94 IBM Informix OnLine Database Server Administrator’s GuideOption DescriptionsThethirdportion of the-p display tracks thenumberof times aresourcewa

Utilities 7-95Option Descriptions-P OptionUse the -P option to obtain a count of big buffer reads, in addition to thestandard profile counts. (Refer to

7-96 IBM Informix OnLine Database Server Administrator’s GuideOption DescriptionsSummary information follows the individual LRU queue information. You

Utilities 7-97Option Descriptions-s OptionUsethe -s optiontodisplaygeneral latch information.(Refertopage 2-41 formore details about latches.) You can

7-98 IBM Informix OnLine Database Server Administrator’s GuideOption Descriptions-t OptionUsethe-toptiontodisplay tblspace informationforactivetblspac

Utilities 7-99Option Descriptions-u OptionUse the -u option to print a profile of user activity. The output described inthis paragraph is provided for

7-100 IBM Informix OnLine Database Server Administrator’s GuideOption DescriptionsThe second section of the -u output describes transactions. This inf

Utilities 7-101Option DescriptionsThe number of active users and the maximum number of users allowed arealso indicated. The maximum number of concurre

1-24 IBM Informix OnLine Database Server Administrator’s GuideMirroring Configuration GuidelinesMirroring Configuration GuidelinesMirroringisnotrequired

7-102 IBM Informix OnLine Database Server Administrator’s Guidetbtape: Logging, Archives, and Restore-z OptionUse the -z option to set the profile coun

Utilities 7-103SyntaxSyntaxIf more than one tape is needed during the logical log backups or during anarchive, tbtape prompts for each additional tape

7-104 IBM Informix OnLine Database Server Administrator’s GuideRequest a Logical Log BackupRequest a Logical Log BackupThe -a option is the equivalent

Utilities 7-105Create an ArchiveCreate an ArchiveThe -s option is the equivalent of the DB-Monitor Create option from theArchive menu. You are prompte

7-106 IBM Informix OnLine Database Server Administrator’s GuideChange Database Logging StatusChange Database Logging StatusThese tbtape command option

Utilities 7-107tbunload: Transfer Binary Data in Page Unitstbunload: Transfer Binary Data in Page UnitsThetbunload utility writesadatabase or tabletot

7-108 IBM Informix OnLine Database Server Administrator’s GuideSyntaxSyntaxIf you do not specify any tape parameter options, tbunload uses the archive

Utilities 7-109Specify Tape ParametersSpecify Tape ParametersYou can use the -b, -s, and -t options individually to override the defaultarchive tape d

8ChapterOnLine Message LogIn This Chapter ... 8-3OnLine Message Log ... 8-3Alphabetized Messages ... 8-5

Installation and Initial Configuration 1-25Physical Log Configuration GuidelinesMIRROROFFSETThe MIRROROFFSET parameter specifies the offset into the dis

8-2 IBM Informix OnLine Database Server Administrator’s Guide

OnLine Message Log 8-3In This ChapterThischapterintroducesthe OnLine MessageLog,aUNIX filespecifiedbytheMSGPATH configuration file parameter.OnLine Messag

8-4 IBM Informix OnLine Database Server Administrator’s GuideOnLine Message LogInformix recommends that you monitor the messagelog onceor twice a dayt

OnLine Message Log 8-5Alphabetized MessagesAlphabetized MessagesAborting Long Transaction: tx 0xnThe logical log has filled beyond the long transaction

8-6 IBM Informix OnLine Database Server Administrator’s GuideAlphabetized MessagesAttempt to write pages nn to a nn page buffer.OnLine detected a page

OnLine Message Log 8-7Alphabetized MessagesThe messages can be interpreted as follows: The first message indicates the inconsistency. The second mess

8-8 IBM Informix OnLine Database Server Administrator’s GuideAlphabetized MessagesCannot execute gtrid_aaaa -- No TP monitor available.(This message i

OnLine Message Log 8-9Alphabetized MessagesCannot Perform CheckpointArecoveryprocessthat isattemptingtorestoreamirrorchunkhasrequesteda checkpoint, bu

8-10 IBM Informix OnLine Database Server Administrator’s GuideAlphabetized MessagesCannot Rollforward from CheckpointOnLineisunabletorecoverthelogical

OnLine Message Log 8-11Alphabetized MessagesChunk number nn pathname -- OnlineThe indicated chunk in a mirrored pair has been recovered and is online(

vi IBM Informix OnLine Database Server Administrator’s GuideStructure of a Blobspace or Dbspace Mirror Chunk ... 2-92OnLine Limits for Chunks ...

1-26 IBM Informix OnLine Database Server Administrator’s GuideLogical Log Configuration GuidelinesRefertopage 1-42forguidelinesondecidinghowmuchdiskspa

8-12 IBM Informix OnLine Database Server Administrator’s GuideAlphabetized MessagesChunk number nn pathname -- Recovery Failed - can’t forkThe indicat

OnLine Message Log 8-13Alphabetized MessagesDbspace dbspacename -- Recovery Begins (pid)Dbspace recovery occurs when mirroring is turned on for a dbsp

8-14 IBM Informix OnLine Database Server Administrator’s GuideAlphabetized MessagesEmpty B-tree node 0xn; Unable to do CopyBackOnLine detected B+ tree

OnLine Message Log 8-15Alphabetized Messagestype is thelog record type (referto tblog); len is the length ofthe log recordin bytes.ERROR: logread()- l

8-16 IBM Informix OnLine Database Server Administrator’s GuideAlphabetized MessagesERROR: page cleaner nn has timed out.A page-cleaner process could n

OnLine Message Log 8-17Alphabetized MessagesFailed to stat chunk chunk_pathname, errno = nnOnLine detectedan error during an operating system stat() c

8-18 IBM Informix OnLine Database Server Administrator’s GuideAlphabetized MessagesINFORMIX-OnLine Must ABORT; Log error nn; us 0xn pid 0xn us_flags 0

OnLine Message Log 8-19Alphabetized MessagesInsufficient resources for index change rollback (partnum = nn, keynum= nn)Not enough disk space is availa

8-20 IBM Informix OnLine Database Server Administrator’s GuideAlphabetized MessagesI/O error, Primary Chunk pathname -- OfflineOnLine detected an I/O

OnLine Message Log 8-21Alphabetized MessagesLevel n Archive CompletedThe archive (of the indicated level) has ended.Level n Archive StartedAn archive

Installation and Initial Configuration 1-27Logical Log Configuration GuidelinesLOGFILESLOGFILES specifies the number of logical log files managed by OnLi

8-22 IBM Informix OnLine Database Server Administrator’s GuideAlphabetized Messages The number of transactions that were committed The number of tra

OnLine Message Log 8-23Alphabetized MessagesNot enough Logical Logfiles, Increase “LOGFILES”Duringadatarestore,thevalueoftheLOGFILES configurationfilepa

8-24 IBM Informix OnLine Database Server Administrator’s GuideAlphabetized MessagesPhysical Recovery Complete: nn Pages RestoredPhysicalrecoveryisthe

OnLine Message Log 8-25Alphabetized MessagesProcess Aborted Abnormally (latch): pid=nn user=nnflags=0xnA database server process was terminated while

8-26 IBM Informix OnLine Database Server Administrator’s GuideAlphabetized Messagesread_record: deleted rowid = 0xn, partnum = 0xnOnLine detected an e

OnLine Message Log 8-27Alphabetized MessagesRemote tape using alternate shell command: <rcmd machine>Thismessageindicatesthataremotetapedeviceha

8-28 IBM Informix OnLine Database Server Administrator’s GuideAlphabetized MessagesSome dirty buffers not written. diskcnt=nn writes=nnnotflsh=nnOnLin

OnLine Message Log 8-29Alphabetized MessagesToo Many Active Transactions, Increase “TRANSACTIONS”During a data restore, the value of the TRANSACTIONS

8-30 IBM Informix OnLine Database Server Administrator’s GuideAlphabetized MessagesTransaction table overflow - user id nn, process id nnA database se

OnLine Message Log 8-31Alphabetized MessagesUser table overflow - user id nn process id nnAdatabase server processattempted to attachtosharedmemorywhe

1-28 IBM Informix OnLine Database Server Administrator’s GuideMessage File GuidelinesMessage File GuidelinesThe console receives messages that deserve

9ChapterProduct EnvironmentIn This Chapter ... 9-3The OnLine Environment ... 9-3OnLine Features ... 9-3Hi

9-2 IBM Informix OnLine Database Server Administrator’s GuideTwo-Phase Commit and Automatic Recovery ... 9-23Coordinator Recovery ...

Product Environment 9-3In This ChapterThis chapter describes three possible OnLine environments: A single OnLine database server operating on a host

9-4 IBM Informix OnLine Database Server Administrator’s GuideOnLine FeaturesHigh PerformanceOnLine achieves high performance through two mechanisms:

Product Environment 9-5OnLine FeaturesFault Tolerance and High AvailabilityOnLine uses several logging and recovery mechanisms to protect dataintegrit

9-6 IBM Informix OnLine Database Server Administrator’s GuideFeatures Beyond the Scope of OnLineDistributed Data QueriesTheIBM Informix STARproductena

Product Environment 9-7What Is Multiple Residency?Blob Scanning or CompressionOnLine receives blob data into an existing table in any one of four ways

9-8 IBM Informix OnLine Database Server Administrator’s GuideWhat Is Multiple Residency? Create multiple configuration files and OnLine database server

Product Environment 9-9What Is Multiple Residency?Figure 9-1Conceptualillustration ofmultipleresidencydiskdiskApplication:TBCONFIGset totbconfig1databa

Installation and Initial Configuration 1-29Logical Log Tape Device GuidelinesThe default value of TAPEDEV is /dev/tapedev.You can set the value of TAP

9-10 IBM Informix OnLine Database Server Administrator’s GuideHow Multiple Residency WorksHow Multiple Residency WorksMultiple residency is possible b

Product Environment 9-11How to Set Up Multiple ResidencyHow to Set Up Multiple ResidencyThissectiondescribesthesix-stepinstallationprocedureformultipl

9-12 IBM Informix OnLine Database Server Administrator’s GuideHow to Set Up Multiple ResidencyStep 2: Edit the Configuration File for the New OnLineUse

Product Environment 9-13How to Set Up Multiple ResidencySERVERNUMThe SERVERNUM parameter specifies the unique value associated with thisOnLine configura

9-14 IBM Informix OnLine Database Server Administrator’s GuideHow to Set Up Multiple ResidencyStep 4: Complete Tuning OnLine Configuration (Optional)Ac

Product Environment 9-15OnLine Administration with IBM Informix STAROnLine Administration with IBM Informix STARThe IBM Informix STAR product enables

9-16 IBM Informix OnLine Database Server Administrator’s GuideSharing Data by Using IBM Informix STARFigure 9-2 illustrates a situation in which data

Product Environment 9-17Sharing Data by Using IBM Informix STARUpdating Multiple OnLine ServersIBM InformixSTARensuresthattransactionsthatspanmorethan

9-18 IBM Informix OnLine Database Server Administrator’s GuideSharing Data by Using IBM Informix STARIn the transaction shown in Figure 9-2, IBM Infor

Product Environment 9-19IBM Informix STAR and Two-Phase Commit ProtocolWithin a client/server network, the identity of the coordinator OnLine isdynami

1-30 IBM Informix OnLine Database Server Administrator’s GuideLogical Log Tape Device GuidelinesOnLine supports a logical log backup option called Con

9-20 IBM Informix OnLine Database Server Administrator’s GuideIBM Informix STAR and Two-Phase Commit ProtocolDuring the postdecision phase the coordin

Product Environment 9-21IBM Informix STAR and Two-Phase Commit ProtocolExample Transaction CommitFigure 9-4 is a simple representation of a two-phase

9-22 IBM Informix OnLine Database Server Administrator’s GuideIBM Informix STAR and Two-Phase Commit ProtocolExample Transaction RollbackFigure 9-5 is

Product Environment 9-23Two-Phase Commit and Automatic RecoveryTwo-Phase Commit and Automatic RecoveryThe two-phase commit protocol includes automatic

9-24 IBM Informix OnLine Database Server Administrator’s GuideTwo-Phase Commit and Automatic RecoveryCoordinator recovery is not needed if the followi

Product Environment 9-25Two-Phase Commit and Automatic RecoveryIf the coordinator is unable to contact one or more of the participants, or ifexecution

9-26 IBM Informix OnLine Database Server Administrator’s GuideTwo-Phase Commit and Automatic RecoveryParticipant RecoveryParticipant recovery occurs w

Product Environment 9-27Two-Phase Commit and Automatic RecoveryIf the participant does not receive contact from the coordinator by the timespecified as

9-28 IBM Informix OnLine Database Server Administrator’s GuideTwo-Phase Commit and Automatic RecoveryFigure 9-7Simpleillustration ofautomaticparticipa

Product Environment 9-29Independent Action and Manual RecoveryPresumed-Abort OptimizationIf the coordinator database server process fails before it ma

Installation and Initial Configuration 1-31Identification Parameter GuidelinesLTAPESIZELTAPESIZE specifies the maximum amount of data that should be wri

9-30 IBM Informix OnLine Database Server Administrator’s GuideHeuristic Decisions: What and WhyIndependent action in and of itself does not create the

Product Environment 9-31Heuristic Decisions: What and WhyThe word heuristic refers to the independent nature of the action; that is, itoccurred at the

9-32 IBM Informix OnLine Database Server Administrator’s GuideHeuristic Decisions: What and WhyOnce a heuristic rollback or end-transaction occurs, yo

Product Environment 9-33Heuristic Decisions: What and WhyWhenever a heuristic rollback occurs, the possibility exists that manualrecovery might be req

9-34 IBM Informix OnLine Database Server Administrator’s GuideHeuristic Decisions: What and WhyIn the first case, when you execute tbmode -Z to end a g

Product Environment 9-35Heuristic Decisions: What and WhyFigure 9-9Characteristics of Heuristic “End-Transaction”When it occurs: A heuristic end-trans

9-36 IBM Informix OnLine Database Server Administrator’s GuideHeuristic RollbackHeuristic RollbackTwo conditions might initiate a heuristic rollback:

Product Environment 9-37Heuristic RollbackIt is important to recognize that this rollback does not close the transaction as itwouldinasingleOnLineenvi

9-38 IBM Informix OnLine Database Server Administrator’s GuideHeuristic RollbackThe next event in the scenario happens at the coordinator OnLine. Thec

Product Environment 9-39Heuristic RollbackHowever,ifthecoordinatorgathersallresponsesfromparticipants, ifatleastone participant reports a heuristic ro

1-32 IBM Informix OnLine Database Server Administrator’s GuideShared-Memory Parameter GuidelinesDBSERVERNAMEDBSERVERNAME specifies a unique nameassocia

9-40 IBM Informix OnLine Database Server Administrator’s GuideHeuristic End-TransactionHeuristic End-TransactionThereis onlyone, rare situation in whi

Product Environment 9-41Heuristic End-TransactionAs a consequence, the transaction remains open. The open transactionpreventsyou frombackinguplogicall

9-42 IBM Informix OnLine Database Server Administrator’s GuideHeuristic End-TransactionIn the first case, when you execute tbmode -Z to end a global tr

Product Environment 9-43Two-Phase Commit Protocol ErrorsTwo-Phase Commit Protocol ErrorsThree two-phase commit protocol errors require special attenti

9-44 IBM Informix OnLine Database Server Administrator’s GuideTwo-Phase Commit and Logical Log RecordsTwo-Phase Commit and Logical Log RecordsSupport

Product Environment 9-45Two-Phase Commit and Logical Log RecordsTABLOCKSThe TABLOCKS logical log record can be written by either a coordinator or apar

9-46 IBM Informix OnLine Database Server Administrator’s GuideTwo-Phase Commit and Logical Log RecordsThe output from tblog contains only the type fiel

Product Environment 9-47Two-Phase Commit and Logical Log RecordsThe coordinator’s commit work record (COMMIT record) contains all infor-mation needed

9-48 IBM Informix OnLine Database Server Administrator’s GuideTwo-Phase Commit and Logical Log RecordsHeuristic Rollback RecordsFigure 9-11 illustrate

Product Environment 9-49Two-Phase Commit and Logical Log RecordsFigure 9-11Writes oflogical log recordsduring a heuristicrollbackAll Participants:Writ

Installation and Initial Configuration 1-33Shared-Memory Parameter GuidelinesUSERSUSERS specifies the maximum number of user processes that can concur-

9-50 IBM Informix OnLine Database Server Administrator’s GuideTwo-Phase Commit and Logical Log RecordsHeuristic End-Transaction RecordsFigure 9-12 ill

Product Environment 9-51Determining Database ConsistencyDetermining Database ConsistencyThissection describes the administrativeprocedurethatmight be

9-52 IBM Informix OnLine Database Server Administrator’s GuideDetermining Database ConsistencyStep 1: Determine Where a Heuristic Decision OccurredThe

Product Environment 9-53Determining Database ConsistencyStep 2: Determine If the Networked Database Contains InconsistentDataSuppose that you have det

9-54 IBM Informix OnLine Database Server Administrator’s GuideDetermining Database ConsistencySteps 3 and 4: Decide If Correction Is NeededIf an incon

Product Environment 9-55Determining Database ConsistencyYou can also use the information in the HEURTX log record to locate all logrecords (at all par

9-56 IBM Informix OnLine Database Server Administrator’s GuideDetermining Database ConsistencyDATABASE tmp;BEGIN WORK;INSERT INTO t VALUES (2);INSERT

Product Environment 9-57IBM Informix STAR Configuration Parameters1. Find all records that were updated.2. Identify their type (insert, delete, update)

9-58 IBM Informix OnLine Database Server Administrator’s GuideTrack a Transaction with tbstat OutputThe default value of DEADLOCK_TIMEOUT is 60 second

Product Environment 9-59Track a Transaction with tbstat OutputImportant: In tbstat -k output, the owner field still displays the address of thedatabase

1-34 IBM Informix OnLine Database Server Administrator’s GuideShared-Memory Parameter GuidelinesBUFFERSBUFFERSspecifiesthemaximumnumberofshared-memoryb

9-60 IBM Informix OnLine Database Server Administrator’s GuideTrack a Transaction with tbstat OutputTransaction flag FieldThe transaction flag field des

Product Environment 9-61Track a Transaction with tbstat OutputTransaction user FieldThe transaction user field displays the shared-memory address of th

9-62 IBM Informix OnLine Database Server Administrator’s GuideTrack a Transaction with tbstat OutputTransaction isolation FieldThe isolation field desc

AAppendixNoticesIBM may not offer the products, services, or features discussedin this document in all countries. Consult your local IBM repre-sentati

A-2 IBM Informix OnLine Database Server Administrator’s GuideThe following paragraph does not apply to the United Kingdom or anyother country where su

Notices A-3Any performance data contained herein was determined in a controlledenvironment. Therefore, the results obtained in other operating environ

A-4 IBM Informix OnLine Database Server Administrator’s GuideTrademarksEach copy or any portion of these sample programs or any derivative work,must i

@IndexOQCAB DEFGHI JKLMN P RSTUVWXYZIndexAAdministration tasksconsistency and recovery 4-5things to avoid 3-116ANSI compliancelevel Intro-19Archiveadm

2 IBM Informix OnLine Database Server Administrator’s GuideOQCABDEFGHIJKLMNPRSTUVWXYZ@description of 2-143Blobblobspace storage statistics 5-5effect o

Index 3OQCABDEFGHIJKLMNPRSTUVWXYZ@CCaching percentagesdescription of 5-10mentioned 5-13, 5-17, 5-19Cautions 3-116Character-special file 1-41Checkpoint

Installation and Initial Configuration 1-35Shared-Memory Parameter GuidelinesCHUNKSCHUNKS specifies the maximum number of chunks supported by OnLine.Th

@4 IBM Informix OnLine Database Server Administrator’s GuideOQCABDEFGHIJKLMNPRSTUVWXYZDDaemon processdescription of 2-33user process type flag 2-30Dat

Index 5OQCABDEFGHIJKLMNPRSTUVWXYZ@creating during initialconfiguration 1-59description of 2-84dropping 3-99ending mirroring 3-105identifying the dbspa

@6 IBM Informix OnLine Database Server Administrator’s GuideOQCABDEFGHIJKLMNPRSTUVWXYZnext extent allocation 2-117reclaiming space in an emptyextent 2

Index 7OQCABDEFGHIJKLMNPRSTUVWXYZ@key entries on root nodepage 2-138key value 2-134leaf node page 2-133, 2-136monitoring integrity 3-79page structure

@8 IBM Informix OnLine Database Server Administrator’s GuideOQCABDEFGHIJKLMNPRSTUVWXYZLoggingblobspace data 4-22buffered logging and fastrecovery 4-40

Index 9OQCABDEFGHIJKLMNPRSTUVWXYZ@LRU_MAX_DIRTY parameterdescription of 1-15how to calculate value 2-59initial configuration value 1-37role in buffer

@10 IBM Informix OnLine Database Server Administrator’s GuideOQCABDEFGHIJKLMNPRSTUVWXYZMSGPATH parameterchanges for multipleresidency 9-13description

Index 11OQCABDEFGHIJKLMNPRSTUVWXYZ@Physical page number 2-124PREPARE logical log record 9-44Presumed-abort optimizationdescription of 9-20implications

@12 IBM Informix OnLine Database Server Administrator’s GuideOQCABDEFGHIJKLMNPRSTUVWXYZtaking offline 3-12Slot tabledescription of 2-121entry number 2

Index 13OQCABDEFGHIJKLMNPRSTUVWXYZ@tbload utilitydescription of 7-47migrating with tbunload 4-63overview of migrationmethods 4-52syntax 7-48tblog util

Table of Contents viiChapter 3 Operating OnLineIn This Chapter ... 3-5Changing Modes ... 3-6Types of OnLine Modes ...

1-36 IBM Informix OnLine Database Server Administrator’s GuideShared-Memory Parameter GuidelinesThe recommended value for LOGBUFF is 16 pages, or 16 m

@14 IBM Informix OnLine Database Server Administrator’s GuideOQCABDEFGHIJKLMNPRSTUVWXYZdbspace blob page 2-146dbspace page 2-120page-header and page-e

Index 15OQCABDEFGHIJKLMNPRSTUVWXYZ@tbtape 7-102tbunload 7-107VVARCHAR data typebyte locks 2-52implications for data rowstorage 2-125indexing considera

Installation and Initial Configuration 1-37Shared-Memory Parameter GuidelinesCKPTINTVLCKPTINTVL specifies the maximum interval, expressed in seconds, t

1-38 IBM Informix OnLine Database Server Administrator’s GuideShared-Memory Parameter GuidelinesDB-Monitordoesnotpromptforthisvalueduringinitializatio

Installation and Initial Configuration 1-39Machine- and Product-Specific Parameter GuidelinesMachine- and Product-Specific Parameter GuidelinesBecause y

1-40 IBM Informix OnLine Database Server Administrator’s GuideOnLine Disk Space AllocationSPINCNTThe SPINCNT parameter affects only multiprocessor mac

Installation and Initial Configuration 1-41OnLine Disk Space AllocationCooked files are unreliable because I/O on a cooked file is managed by theUNIX op

1-42 IBM Informix OnLine Database Server Administrator’s GuideOnLine Disk Space AllocationCalculate Root dbspace SizeAnalyze your application to estim

Installation and Initial Configuration 1-43OnLine Disk Space AllocationProject Total Space RequirementsThe amount of additional disk space needed for

1-44 IBM Informix OnLine Database Server Administrator’s GuideOnLine Disk Space AllocationAfter you decide how you plan to define the chunks, decide on

Installation and Initial Configuration 1-45OnLine Disk Space AllocationFigure 1-2illustratesfourguidelinesforplanningthephysicallayoutofyourOnLine dat

viii IBM Informix OnLine Database Server Administrator’s GuideIf the Logical Log Files Fill During an Archive... 3-59If an Archive Terminates Prem

1-46 IBM Informix OnLine Database Server Administrator’s GuideOnLine Disk Space AllocationCriticaltablesanddatabasesshould bemirrored.Therootdbspacesh

Installation and Initial Configuration 1-47OnLine Disk Space AllocationThe logs contain critical information and should be located in mirroreddbspaces

1-48 IBM Informix OnLine Database Server Administrator’s GuideOnLine Disk Space AllocationRaw File SpaceConsult your UNIX system manuals for instructi

Installation and Initial Configuration 1-49OnLine Disk Space AllocationEvaluate UNIX Kernel ParametersYour OnLine product arrives with a machine-speci

1-50 IBM Informix OnLine Database Server Administrator’s GuideConfiguration ChecklistConfiguration ChecklistFigure 1-3is achecklist to help you verifyth

Installation and Initial Configuration 1-51Enter Your Configuration and Initialize OnLineEnter Your Configuration and Initialize OnLineWhen you configure

1-52 IBM Informix OnLine Database Server Administrator’s GuideEnter Your Configuration and Initialize OnLineThe disk parameters initialization screen a

Installation and Initial Configuration 1-53Setting Shared Memory ParametersSetting Shared Memory ParametersLike the disk parameters screen, the shared

1-54 IBM Informix OnLine Database Server Administrator’s GuideInitialize OnLineInitialize OnLineOnLinepromptsyouforconfirmationthatyouwishtoinitializei

Installation and Initial Configuration 1-55Set Your Environment VariablesSQLEXECThe value of SQLEXEC directs the front-end processes to a specific data

Table of Contents ixChange the Maximum Number of Dbspaces... 3-111Change the Maximum Number of Locks ... 3-112Change the Maximum Number of Tb

1-56 IBM Informix OnLine Database Server Administrator’s GuideModify UNIX Startup and Shutdown ScriptsIf your environment contains a single OnLine dat

Installation and Initial Configuration 1-57Modify UNIX Startup and Shutdown ScriptsStartupAdd UNIX and OnLine utility commands to the UNIX startup scr

1-58 IBM Informix OnLine Database Server Administrator’s GuideModify UNIX Startup and Shutdown ScriptsShutdownAdd UNIX and OnLine utility commands to

Installation and Initial Configuration 1-59Create Blobspaces and DbspacesCreate Blobspaces and DbspacesAfter OnLine is initialized, you can create blo

1-60 IBM Informix OnLine Database Server Administrator’s GuideOnLine Error Message FormatOnLine Error Message FormatThe OnLine error message format is

2ChapterSystem ArchitectureIn This Chapter ... 2-7Initialization ... 2-7Initialization Commands ... 2-8

2-2 IBM Informix OnLine Database Server Administrator’s GuideOnLine User Processes... 2-22How User Processes Attach to Shared Memory ..

System Architecture 2-3LRU Queues and Buffer Pool Management...2-58LRU_MAX_DIRTY ...2-59LRU_MIN_DIRTY ...2-59How a

2-4 IBM Informix OnLine Database Server Administrator’s GuideDbspace and Blobspace... 2-84Database ... 2-85Tblspace ...

System Architecture 2-5Structure of an Extent .....2-114Extent Size......2-114Page Types ......2-115Next Extent