DB2 - Problem description
Problem IT18835 | Status: Closed |
LONG QUERY RUNTIME WITH INTRA-PARALLEL AND COMPRESSED INDEXES | |
product: | |
DB2 FOR LUW / DB2FORLUW / A50 - DB2 | |
Problem description: | |
SQL queries on large tables using compressed indexes may show long runtimes, when the used index has a low cardinality and the query degree is larger than 1. In a db2 trace you can see that most time is spent in function sqliSkipRangeForward One agent stack shows: sqliRL_CountRidsFromCompressedPage sqliSkipRangeForward sqliFindEndOfRange sqliGetNxtRng sqliGetNxtRng sqliGetNxtRng sqldIndexFetch sqldRowFetch sqldRowFetch sqlritaSimplePerm sqlriSectInvoke sqlrr_subagent_router Other sub agents are in a latch conflict waiting for latch SQLO_LT_SQLI_PARSCAN__parScanLatch. Stacks may show: thread_wait getConflictComplex sqliGetNxtRng sqldIndexFetch sqldRowFetch sqldRowFetch sqlritaSimplePerm sqlriSectInvoke sqlrr_subagent_router | |
Problem Summary: | |
**************************************************************** * USERS AFFECTED: * * ALL * **************************************************************** * PROBLEM DESCRIPTION: * * See Error Description * **************************************************************** * RECOMMENDATION: * * Upgrade to Db2 10.5 Fix Pack 9 or higher * **************************************************************** | |
Local Fix: | |
Either don´t use a compressed index or set query degree to 1 for the affected query or globally (DFT_DEGREE=1). | |
Solution | |
First fixed in Db2 10.5 Fix Pack 9 | |
Workaround | |
not known / see Local fix | |
Timestamps | |
Date - problem reported : Date - problem closed : Date - last modified : | 16.01.2017 29.09.2017 29.09.2017 |
Problem solved at the following versions (IBM BugInfos) | |
9.0. | |
Problem solved according to the fixlist(s) of the following version(s) |