Informix - Problem description
Problem IT27616 | Status: Closed |
QUERIES PERFORMING INDEX SELF JOIN MAY NOT YIELD FREQUENTLY ENOUGH LEADING TO BLOCKED CHECKPOINT REQUESTS | |
product: | |
INFORMIX SERVER / 5725A3900 / C10 - IDS 12.10 | |
Problem description: | |
Certain types of SQL query that use an index self join on large tables where the index pages are held in the buffer pool may not yield frequently enough during their execution. This could result in a blocked checkpoint request if another thread is in critical section and waiting on the result of an I/O request and that result needs to be processed by the kaio thread running on the same CPU VP as the non-yielding query. A stack of the running thread may be similar to: btfind btsearch kposition rsstart fmstart nextlkeyrg startsubq scan_next getrow fetchrow exfetch sql_nfetch sq_nfetch sqmain As the thread is in a running state the top few functions may or may not be present. The key indicator for this problem is the function nextlkeyrg which may perform a loop operation. | |
Problem Summary: | |
**************************************************************** * USERS AFFECTED: * * Users of IDS prior to 12.10.xC13. * **************************************************************** * PROBLEM DESCRIPTION: * * Queries performing index self join may not yield frequently * * enough leading to blocked checkpoint requests. * **************************************************************** * RECOMMENDATION: * **************************************************************** | |
Local Fix: | |
Solution | |
Workaround | |
not known / see Local fix | |
Timestamps | |
Date - problem reported : Date - problem closed : Date - last modified : | 27.12.2018 03.10.2019 03.10.2019 |
Problem solved at the following versions (IBM BugInfos) | |
12.10.xC13 | |
Problem solved according to the fixlist(s) of the following version(s) |