A fix is available
APAR status
Closed as program error.
Error description
Deadlock on SYSIBM.SYSTABLESPACESTATS in DSNDB06.SYSRTSTS by mass delete on multiple tables on same tablespace.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: DB2 10 for z/OS and DB2 11 for z/OS * * customers who may run mass delete table * * jobs on multi-table table spaces. * **************************************************************** * PROBLEM DESCRIPTION: MSGDSNT501I RC00C90088 deadlock on the * * Real-time Statistics (RTS) catalog * * table (SYSIBM.SYSTABLESPACESTATS) may * * occur when running multiple SQL mass * * delete jobs on multi-table table * * spaces concurrently. * **************************************************************** * RECOMMENDATION: Apply corrective PTF when available * **************************************************************** Deadlock may occur on SYSIBM.SYSTABLESPACESTATS table when running multiple mass delete jobs on multi-table table spaces concurrently. Below is a possible scenario for a deadlock. Job #1 mass deletes table 1 in table space A without a commit. Job #2 mass deletes table 3 in table space B without a commit. Job #2 mass deletes table 2 in table space A. Job #1 mass deletes table 4 in table space B. SYSIBM.SYSTABLESPACESTATS table maintains statistics at the table space level and not at the table level. When job #1 mass deletes table 1 in table space A, a row level lock is obtained for table space A. Similarly, job #2 obtains a row level lock for table space B when it mass deletes table 3 in table space B. Because job #1 does not commit, job #2 that mass deletes table 2 in table space A needs to wait for the lock to be released by job #1. In the mean time, job #1 that mass deletes table 4 in table space B waits for job #2 to release the lock on table space B. A deadlock is detected. MSGDSNT375I, MSGDSNT376I, and/or DSNT501I may be issued. Additional keywords: DSNT375I DSNT376I SYSTABLESPACESTATS
Problem conclusion
RTS mass delete processing has been modified to resolve the reported deadlock problem. Following a mass delete, some of the RTS statistics, such as TOTALROWS, DATASIZE, and NPAGES, may become null. This is mainly because, for a multi-table table space, the number of records removed by a mass delete on a table is unknown. With this APAR fix applied, the period when the RTS data may stay nulls becomes longer as in-memory statistics are not externalized during a mass delete. In a data sharing environment, RTS statistics may not be accurate. This problem will be addressed by a future APAR. While it is not necessary to apply the APAR fix on all data sharing members at once, the fix does need to be on members that may run mass delete jobs on multi-table table spaces concurrently.
Temporary fix
Comments
×**** PE15/07/02 FIX IN ERROR. SEE APAR PI37019 FOR DESCRIPTION
APAR Information
APAR number
PI28671
Reported component name
DB2 OS/390 & Z/
Reported component ID
5740XYR00
Reported release
A10
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2014-10-29
Closed date
2014-12-02
Last modified date
2015-09-09
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
UI23552 UI23553
Modules/Macros
DSNIRTSU DSNIRTSX
Fix information
Fixed component name
DB2 OS/390 & Z/
Fixed component ID
5740XYR00
Applicable component levels
Fix is available
Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.
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Document Information
Modified date:
06 May 2020