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1938882 - How to repair inconsistent indexes, tables, or columns in IQ database -SAP IQ

Symptom

Encountering read/write problems in IQ, may occur, IQ might fail to read or write data on a table and the log shows the follwing error message:

main Bufman: Incorrect page header read; buffer={btype=13,nlb=16,blk=3437,pbn=2912907180,npb=7,uid=61799794,txn=115885128,sp=2,flgs=0x8418 page={btype=13,nlb=17918,npb=55376,ctr=77
main Bufman: An error was detected on a database page. You may have a damaged index. For additional information, please check your IQ message file or run sp_iqcheckdb.

This kind of error message shows there are some inconsistent errors in the IQ database, using sp_iqcheckdb to check the table or the whole database to confirm the problem.

As a next step, the DBCC command "sp_iqcheckdb 'verify database'" or "sp_iqcheckdb 'verify table <table_name>'", was run and reports of inconsistent indexes were detected.

This is a sample output of sp_iqcheckdb:

Index Summary           |                                  |
========================|==================================|=====
** Inconsistent Index   |                                  |
   Count                |1                                 |*****
   Verified Index       |                                  |
   Count                |85                                |
========================|==================================|=====
Index Statistics        |                                  |
========================|==================================|=====
** Inconsistent Index   |contact.DBA.idx01_HNG             |*****
   ...
   Verified Index       |fin_data.DBA.ASIQ_IDX_T209_C3_HG  |
   Verified Index       |fin_data.DBA.ASIQ_IDX_T209_C4_FP  |
   ...
   Verified Index       |employee.DBA.ASIQ_IDX_T212_C19_FP |
   Verified Index       |employee.DBA.ASIQ_IDX_T212_C20_FP |
   Verified Index       |iq_dummy.DBA.ASIQ_IDX_T213_C1_FP  |
** Extra Index RIDs     |5                                 |*****
   FP Indexes Checked   |68                                | 
   HNG Indexes Checked  |1                                 |
   HG Indexes Checked   |17                                |
                        |                                  |

In this output, there is one inconsistent index "contact.DBA.idx01_HNG" detected.

Actually, sp_iqcheckdb may report many other errors, the following table lists those messages which are reported for problems that DBCC cannot repair:

Messages for Problems DBCC Cannot Repair

DBCC message

Description/action

FP Lookup Table Inconsistencies

An unrepairable error, where the 1-byte or 2-byte FP is internally inconsistent.

VDO Incorrect First Available Fields

VDO Incorrect Next Available Fields

VDO Incorrect Used Count Fields

VDO Incorrect In-use Bitvec

VDO Incorrect In-use Bitmap

VDO Incorrect Partial Bitmap

VDO Incorrect Deleted Bitmaps

Unrepairable errors that can cause entire tables to be inaccessible. You must force drop the inconsistent table to resolve these errors.

Blocks with Multiple Owners

1st Multiple Owner PBN

Blocks in use by more than one database object. Drop the object that is reported as inconsistent.

DBCC Meta-data Errors

Blockmap Invalid Chunksize Error Count

Blockmap Compression Bit Error Count

Blockmap Invalid Block Number Error Count

An internal page mapping structure is inconsistent and the object needs to be dropped.

DBCC Inconsistent Disk Block Headers

DBCC Decompress Errors

The storage for the object is inconsistent and the object needs to be dropped.

What is the next step?


Read more...

Environment

  • SAP IQ 16.0
  • SAP IQ 16.1

Product

SAP IQ 16.0 ; SAP Sybase IQ 15.2 ; SAP Sybase IQ 15.4

Keywords

drop, force_drop, FORCE_DROP, inconsistent object, sp_iqcheckdb, sp_iqrebuildindex, repair, FP index, DBCC message, problem, corrupt , , KBA , BC-SYB-IQ , Sybase IQ , How To

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