Re: [PERFORM] Slow query: bitmap scan troubles

On Mon, Jan 14, 2013 at 12:56:37PM -0500, Tom Lane wrote:
> > The reported behavior was that the planner would prefer to
> > sequential-scan the table rather than use the index, even if
> > enable_seqscan=off.  I'm not sure what the query looked like, but it
> > could have been something best implemented as a nested loop w/inner
> > index-scan.
> 
> Remember also that "enable_seqscan=off" merely adds 1e10 to the
> estimated cost of seqscans.  For sufficiently large tables this is not
> exactly a hard disable, just a thumb on the scales.  But I don't know
> what your definition of "extremely large indexes" is.

Wow, do we need to bump up that value based on larger modern hardware?

-- 
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + It's impossible for everything to be true. +