| From: | Jeff Davis <pgsql(at)j-davis(dot)com> |
|---|---|
| To: | Robert Haas <robertmhaas(at)gmail(dot)com> |
| Cc: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, Simon Riggs <simon(at)2ndquadrant(dot)com>, Teodor Sigaev <teodor(at)sigaev(dot)ru>, Pgsql Hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: GIN fast insert |
| Date: | 2009-02-24 19:28:31 |
| Message-ID: | 1235503711.18299.1.camel@dell.linuxdev.us.dell.com |
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| Lists: | pgsql-hackers |
On Tue, 2009-02-24 at 00:18 -0500, Robert Haas wrote:
> It only took me about 5 minutes to come up with a test case against CVS
> HEAD where disabling index scans resulted in a significant dropoff in
> performance. Here it is:
On the other hand, Teodor showed a typical use case and a very
substantial performance gain:
http://archives.postgresql.org/message-id/497F4606.6070303@sigaev.ru
My impression is that GIN is used almost entirely for full text search.
Even though GIN is actually quite general (as the BTree patch shows),
the current users we have to worry about are a fairly narrow group
(correct me if I'm wrong here).
I wonder how many people really use GIN with non-bitmap scans for some
benefit? And even if the benefit exists, does the planner have a way to
identify those cases reliably, or does it have to be done manually?
Regards,
Jeff Davis
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