Hello everybody, I am currently trying to squeeze some performance out of the current predicate evaluation implementation. In fact I was able to get some positive results. I have some more points on my developement plan, but I am facing the problem that theses changes will only help very little when talking about runtimes.
Therefore I am not able to quantify these changes at the moment as my overall query runtimes do not seem to be stable across instance restarts. Consider the following example: Start postgres, run to warm up buffers measure query wall clock time: 24.141s Stop Postgres: Start postgres, run to warm up buffers measure query wall clock time: 25.845 Stop Postgres I expect my current changes to be resposible for about 0.2-0.3s for this query but because of the huge time differences I am not able to quantify my changes. Maybe somebody can tell me about a better approach to quantify my changes or give me some input on how to get more stable postgres time measurements. Thank you very much. Kind regards Dennis If needed please find some configuration parameters below max_connections = 2 superuser_reserved_connections = 1 ssl = off shared_buffers = 20GB max_prepared_transactions = 0 work_mem = 500MB fsync = off archive_mode = off hot_standby = off effective_cache_size = 20GB logging_collector = off debug_print_parse = off debug_print_rewritten = off debug_print_plan = off debug_pretty_print = off log_checkpoints = off log_connections = off log_disconnections = off log_duration = off log_hostname = off track_activities = off track_counts = off track_io_timing = off track_functions = none log_parser_stats = off log_planner_stats = off log_executor_stats = off log_statement_stats = off autovacuum = off -- View this message in context: http://postgresql.1045698.n5.nabble.com/Quantify-small-changes-to-predicate-evaluation-tp5807190.html Sent from the PostgreSQL - hackers mailing list archive at Nabble.com. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
