[DERBY-5206] Investigate reduced throughput in some of the nightly performance tests

• Type: Task
• Status: Closed
• Priority: Major
• Resolution: Invalid
• Affects Version/s: 10.8.1.2
• Component/s: SQL
• Environment: Solaris 10 5/08 s10x_u5wos_10 X86; java version "1.6.0"; Java(TM) SE Runtime Environment (build 1.6.0-b105); Java HotSpot(TM) Server VM (build 1.6.0-b105, mixed mode)
• Bug behavior facts: Performance
• Assignee: Unassigned
• Reporter: Knut Anders Hatlen
• Created: 27/Apr/11 11:37
• Updated: 13/May/11 07:24
• Resolved: 13/May/11 07:24

Description

The last two months, the nightly performance regression tests (http://home.online.no/~olmsan/derby/perf/) have shown results that are slightly lower than normal for the following test:

• Single Record Select, Non-primary non-indexed column - http://home.online.no/~olmsan/derby/perf/select_sec_noindex_1y.html

• TPC-B like load (aka bank_tx) - http://home.online.no/~olmsan/derby/perf/tpcb_1y.html

For example, when averaging the results from 2011-03-01 to 2011-04-26 and comparing them to the average for the two preceding months (2011-01-01 to 2011-03-01), I see these changes:

Select, single-threaded: 17.05 tx/s -> 16.81 tx/s (down 1.4%)
Select, 4 threads: 25.50 tx/s -> 24.70 tx/s (down 3.1%)
Select, 16 threads: 25.17 tx/s -> 24.47 tx/s (down 2.8%)

bank_tx, single-threaded: 1931 tx/s -> 1904 tx/s (down 1.4%)
bank_tx, 4 threads: 2628 tx/s -> 2589 tx/s (down 1.5%)
bank_tx, 16 threads: 3584 tx/s -> 3519 tx/s (down 1.8%)

Issue Links

• relates to: DERBY-4233 Lower tablescan performance right after database creation in 10.5
• relates to: DERBY-5067 Performance regression tests should populate tables before creating indexes