Re: [PERFORM] why is bitmap index chosen for this query?

[Stephen Byers]

"Steinar H. Gunderson" <[EMAIL PROTECTED]> wrote:

It sounds like PostgreSQL badly overestimates the cost of the index scan.
Does the table perchance fit completely into memory, without
effective_cache_size indicating that?

Don't know the exact way to answer your question, but my initial instinct is "no way."

  select pg_relation_size('packets');

 pg_relation_size
------------------
      19440115712

19GB.  So it's a big table.  The query I submitted earlier returns about 13M rows and the table currently has about 38M rows.

 

 

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