Josh Kupershmidt wrote:
On Fri, Feb 5, 2010 at 12:02 PM, Steve Crawford
<scrawf...@pinpointresearch.com
<mailto:scrawf...@pinpointresearch.com>> wrote:
What causes an increment to idx_scan in pg_stat_user_indexes?
"Select" queries only? When used to enforce column uniqueness?
When used for foreign-key constraints?
The docs are a little sparse here:
http://developer.postgresql.org/pgdocs/postgres/monitoring-stats.html
Hence the reason for my query - to find out the precise, detailed
definition of those columns.
but I'm assuming that counter gets incremented every time there's an
index scan using the index in question, which could occur with SELECT,
UPDATE, DELETE, etc. queries which make use of this index. See this
thread for related questions and answers, and the note about bitmap
index scans:
http://archives.postgresql.org/pgsql-admin/2006-01/msg00319.php
Well, not really. If that were true, every table with a primary key
would show index-scans on the associated index - a necessary condition
of determining uniqueness. But I have tables with primary-keys,
thousands to millions of rows, and zero index-scans on the primary-key
index.
-Steve
