Jeremy Haile wrote:
I changed the table-specific settings so that the ANALYZE base threshold
was 5000 and the ANALYZE scale factor is 0. According to the documented
formula: analyze threshold = analyze base threshold + analyze scale
factor * number of tuples, I assumed that this would cause the table to
be analyzed everytime 5000 tuples were inserted/updated/deleted.
That is right, and exactly how the scaling factor / base value are
supposed to work, so this should be fine.
However, the tables have been updated with tens of thousands of inserts
and the table has still not been analyzed (according to
pg_stat_user_tables). Does a scale factor of 0 cause the table to never
be analyzed? What am I doing wrong? I'm using PG 8.2.1.
No a scaling factor of 0 shouldn't stop the table from being analyzed.
Unless it's just a bug, my only guess is that autovacuum may be getting
busy at times (vacuuming large tables for example) and hasn't had a
chance to even look at that table for a while, and by the time it gets
to it, there have been tens of thousands of inserts. Does that sounds
plausible?
Also, are other auto-vacuums and auto-analyzes showing up in the
pg_stats table? Maybe it's a stats system issue.
