On 12/06/2012 06:13 PM, tim_wilson wrote:
This drift gets more confusing. My small table A (60K rows) is not being inserted to (except one or two rows) it is getting thousands of updates a minute. Analyze and vacuum on the table are running regularly. But sometimes ,every time the vacuum runs the reltuples value jumps up. Sometime bloating by 4 times the actualy size of the table (have seen 10 times) The impact of this on the query plans is evident straight away. Joins from all small A to large table B (55 Million rows) on the large B's primary key start seq scanning. Some sort of threshold is being hit where the planner believes that the size of A is big enough that given we are requesting all of A we might as well scan all of B. Also even though the table has been clustered and even vacuum full'ed the relpages value continues to grow. Any answers?
1) FYI an update is a delete/insert, so you are actually getting thousands of inserts a minute. 2) As to why the size is growing- Are there open transactions holding old row versions around?
-- Adrian Klaver adrian.klaver@xxxxxxxxx -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
