Fixes are available
DB2 Version 9.5 Fix Pack 3b for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 4 for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 3a for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 3 for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 4a for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 5 for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 6a for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 7 for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 8 for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 9 for Linux, UNIX, and Windows
DB2 Version 9.5 Fix Pack 10 for Linux, UNIX, and Windows
APAR status
Closed as program error.
Error description
The Instance will trap/panic due to an as-yet-unknown problem where the Sort facility, during the merge phase, attempts to unfix a bufferpool page (belonging to a temporary table) that has already been unfixed. The problem is very rare, and the root cause is still unknown. This APAR will add defensive code that checks if the page is already unfixed before unfixing it, and if so, it will force the application using the Sort to fail with a -901, instead of causing the instance to panic/trap. A stack trace containing functions sqlbufix and sqlsmerg is common what this problem occurs: __1cTsqlbLatchPinnedPage6FpnLSQdDLB_FIX_CB__i_(0xffffffff7e7b8f8 8,0x4da650760,0x10000,0x397c,0xffff7c00,0xffff7fff) + 0x338 __1cIsqlbufix6FpnLSQdDLB_FIX_CB_cc_i_(0x4,0x4da650760,0x0,0x2,0x 242299ec0,0x2) + 0x180 __1cMsqlsmergerec6FpnUsqle_agent_privatecb_pnKSQdDLS_SLDES_pnKS QdDLS_MBUFS_L_i_(0xffffffff7331b040,0x604f1efa0,0x2,0xffffffff73 210080,0x20100020,0xffffffff7efbc920) + 0x608 __1cIsqlsfetc6FpnUsqle_agent_privatecb_pnISQdDLD_CCB_ipnKSQdDLD_ DPRED_ppnKSQdDLD_VALUE_pnISQdDLZ_RID_pc_i_(0xffffffff7331b040,0x 0,0x1,0xffffffff7183be88,0x1d,0xffffffffffffffff) + 0xbbc __1cUsqlriFetchSortedTemp6FpnIsqlrr_cb_pnJsqlri_tao_l_i_(0xfffff fff73310ea0,0xffffffff7183bce8,0x3,0xffffffff7183bce8,0x10000,0x 80) + 0x30 __1cKsqlriFetch6FpnIsqlrr_cb_pnJsqlri_tao_l_i_(0xffffffff73310ea 0,0xffffffff7183bce8,0x3,0x7f7b8,0x0,0x1) + 0x5c __1cHsqlrita6FpnIsqlrr_cb__i_(0x0,0xffffffff73310ea0,0x0,0xfffff fff7183bce8,0xffffffff7efbc888,0x1578) + 0x6cc __1cPsqlriSectInvoke6FpnIsqlrr_cb_pnMsqlri_opparm__i_(0xffffffff 73310ea0,0xffffffff7cf42f58,0x1578,0xffffffff7183c228,0xffffffff 7331b040,0x0) + 0x29c ...snip...
Local fix
Problem summary
ERROR DESCRIPTION: The Instance will trap/panic due to an as-yet-unknown problem where the Sort facility, during the merge phase, attempts to unfix a bufferpool page (belonging to a temporary table) that has already been unfixed. The problem is very rare, and the root cause is still unknown. This APAR will add defensive code that checks if the page is already unfixed before unfixing it, and if so, it will force the application using the Sort to fail with a -901, instead of causing the instance to panic/trap. A stack trace containing functions sqlbufix and sqlsmerg is common what this problem occurs: __1cTsqlbLatchPinnedPage6FpnLSQdDLB_FIX_CB__i_(0xffffffff7e7b8f8 8,0x4da650760,0x10000,0x397c,0xffff7c00,0xffff7fff) + 0x338 __1cIsqlbufix6FpnLSQdDLB_FIX_CB_cc_i_(0x4,0x4da650760,0x0,0x2,0x 242299ec0,0x2) + 0x180 __1cMsqlsmergerec6FpnUsqle_agent_privatecb_pnKSQdDLS_SLDES_pnKS QdDLS_MBUFS_L_i_(0xffffffff7331b040,0x604f1efa0,0x2,0xffffffff73 210080,0x20100020,0xffffffff7efbc920) + 0x608 __1cIsqlsfetc6FpnUsqle_agent_privatecb_pnISQdDLD_CCB_ipnKSQdDLD DPRED_ppnKSQdDLD_VALUE_pnISQdDLZ_RID_pc_i_(0xffffffff7331b040,0x 0,0x1,0xffffffff7183be88,0x1d,0xffffffffffffffff) + 0xbbc __1cUsqlriFetchSortedTemp6FpnIsqlrr_cb_pnJsqlri_tao_l_i_(0xfffff fff73310ea0,0xffffffff7183bce8,0x3,0xffffffff7183bce8,0x10000,0x 80) + 0x30 __1cKsqlriFetch6FpnIsqlrr_cb_pnJsqlri_tao_l_i_(0xffffffff73310ea 0,0xffffffff7183bce8,0x3,0x7f7b8,0x0,0x1) + 0x5c __1cHsqlrita6FpnIsqlrr_cb__i_(0x0,0xffffffff73310ea0,0x0,0xfffff fff7183bce8,0xffffffff7efbc888,0x1578) + 0x6cc __1cPsqlriSectInvoke6FpnIsqlrr_cb_pnMsqlri_opparm__i_(0xffffffff 73310ea0,0xffffffff7cf42f58,0x1578,0xffffffff7183c228,0xffffffff 7331b040,0x0) + 0x29c ...snip...
Problem conclusion
First fixed in DB2 UDB Version 9.1 FixPak 6 and 9.5, FixPak 3.
Temporary fix
Comments
APAR Information
APAR number
IZ20211
Reported component name
DB2 UDB ESE SOL
Reported component ID
5765F4102
Reported release
950
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2008-04-15
Closed date
2009-04-16
Last modified date
2009-04-16
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Modules/Macros
engn_sqs
Fix information
Fixed component name
DB2 UDB ESE SOL
Fixed component ID
5765F4102
Applicable component levels
R950 PSY
UP
Document Information
Modified date:
16 April 2009