Обсуждение: REINDEX question
Good morning,
We are at Postgres 7.4.5. I have encountered inaccuracies
after reindexing related to the statistics posted back to the PG_CLASS table
For instance:
1. We have a ‘queues’ table with 6 indexes. We are at 110,000 rows in this table.
When I reindex, the RELPAGE count decreases as expected but the RELTUPLE
Count increases to about 132,000 in all indexes. I check and there are still
Only 110,000 rows on the table.
2. We have a table that is quite volatile in its numbers, ranging from 100 to 6 million rows.
Last week we were at 50,000 rows but PG_CLASS.RELTUPLES showed 6 million for
The indexes. I reindexed and, again the RELPAGES count went down but the RELTUPLES
Number went down to just 3 million.
Again a count after reindex gave the actual row count at 52,000.
Does anybody have any insight why this is happening and what I can do in the short term?
I know we are at a back-leveled version so perhaps the long-term answer is to upgrade.
Thank you,
Mark Steben
Senior DBA - AutoRevenue
Direct dial phone number: 413-327-3045
Please visit our new website at www.autorevenue.com
"We do all the work.... you make all the money"
"Mark Steben" <msteben@autorevenue.com> writes:
> We are at Postgres 7.4.5. I have encountered inaccuracies
> after reindexing related to the statistics posted back to the PG_CLASS
> table
reindex enters the exact number of tuples indexed into
pg_class.reltuples. If there are more than you expect, that says there
are some dead-but-not-removable tuples in the relation. Check for old
open transactions that might still be able to see old versions of rows.
VACUUM VERBOSE should report the same number of unremovable rows BTW.
regards, tom lane