Database crashed during table reorg due to failing index leaf
prefetching logic, as reported by the following probe:
2011-04-03-02.19.38.282689+000 I7036583A2349 LEVEL: Severe
PID : 1274058 TID : 12081 PROC : db2sysc
0
INSTANCE: xxxxxx NODE : 000
EDUID : 12081 EDUNAME: db2pfchr (xxx) 0
FUNCTION: DB2 UDB, buffer pool services, sqlbServiceLeafRequest,
probe:4479
DATA #1 : String, 9 bytes
The error occurred while DB2 was getting ready to prefetch index
leaf pages from disk. This type of request is made by the index
leaf page scanner during a REORG TABLE. Defensive code check
determines that the number of page entries exceeds the page
array size. Prior to RID list compression an array size equal to
pageSize was enough to store all of the RIDs from a single index
page, but with RID list compression this is no longer true. In
any case, this internal programming error should be gracefully
handled; it should not bring down database. The condition that
brought down the database originates from freeing the same
pointer twice while handling the previous error. The following
db2diag.log entry alerts to the memory error:
2011-04-03-02.19.38.287016+000 I7050099A1579 LEVEL: Severe
PID : 1274058 TID : 12081 PROC : db2sysc
0
INSTANCE: xxxxxx NODE : 000
EDUID : 12081 EDUNAME: db2pfchr (xxx) 0
FUNCTION: DB2 UDB, SQO Memory Management,
sqloDiagnoseFreeBlockFailure, probe:10
MESSAGE : Possible memory corruption detected.
DATA #1 : ZRC, PD_TYPE_ZRC, 4 bytes
0x820F0002
DATA #2 : Corrupt block address, PD_TYPE_CORRUPT_BLK_PTR, 8
bytes
0x00000001112f2540
DATA #3 : Block header, PD_TYPE_BLK_HEADER, 24 bytes
0x00000001112F2528 : FAB0 0000 0011 12F0 0000 0000 0000 0000
................
0x00000001112F2538 : 0000 0000 0000 0000
........
DATA #4 : Data header, PD_TYPE_BLK_DATA_HEAD, 48 bytes
0x00000001112F2540 : 0000 0000 0000 DAC0 02FD 0626 02FD 06B0
...........&....
0x00000001112F2550 : 02FD 072F 02FD 09B0 02FD 09B9 02FD 09BD
.../............
0x00000001112F2560 : 02FD 0C83 02FD 1005 02FD 10E2 02FD 183F
...............?
CALLSTCK:
[0] 0x0900000006734ABC pdLog + 0xEC
[1] 0x0900000002EA78D4
@79@sqloDiagnoseFreeBlockFailure__FP8SMemFBlk + 0x150
[2] 0x09000000064877D4 sqlofmblkEx + 0x58
[3] 0x090000000615580C sqlbServiceLeafRequest__FP11SQLB_pfMisc
+ 0x440
[4] 0x0900000003762648
sqlbPFPrefetcherEntryPoint__FP16sqbPrefetcherEdu + 0x46C
[5] 0x09000000064DCB28 RunEDU__16sqbPrefetcherEduFv + 0x2C
[6] 0x09000000064DB4B0 EDUDriver__9sqzEDUObjFv + 0x1C0
[7] 0x09000000064D2F18 sqloEDUEntry + 0x260
[8] 0x09000000002CE4F4 _pthread_body + 0xDC
[9] 0xFFFFFFFFFFFFFFFC ?unknown + 0xFFFFFFFF |
