| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | Luca Ferrari <fluca1978(at)infinito(dot)it> |
| Cc: | PostgreSQL General <pgsql-general(at)postgresql(dot)org> |
| Subject: | Re: empty table explain... |
| Date: | 2008-10-27 20:01:49 |
| Message-ID: | 23680.1225137709@sss.pgh.pa.us |
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| Lists: | pgsql-general |
Luca Ferrari <fluca1978(at)infinito(dot)it> writes:
> I'm curious to know why, if a table is empty, it seems that an ANALYZE
> of the table does not insert any stats in the pg_stats table,
Uh ... because there are no stats to insert. The only available
information is that the table is empty, which is something we track in
pg_class not pg_stats.
> Second, if I execute an EXPLAIN
> on an empty table, even after an ANALYZE of the table, I got an explain that
> proposes me a row numbers and size that I cannot understand (since it seems to
> be different depending on the table definition).
That's the planner not wanting to bet on an empty table staying empty.
regards, tom lane
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