On Feb 17, 2004, at 1:41 PM, Todd Fulton wrote:
spank_prod=# \d idx_spk_tgp_tgpid Index "idx_spk_tgp_tgpid" Column | Type ---------------+----------------------- tgpid | bigint directoryname | character varying(64) btree
A couple of things to note:
1. What version of PostgreSQL are you running? I'm currently running 7.3.4 and my output of \d on a table shows more index information than yours does. If you're running anything earlier than 7.3, I'd definitely recommend that you upgrade.
2. Why are you using a multicolumn index in this case? You might want to read the page in the documentation that discusses multi-column indexes specifically.
http://www.postgresql.org/docs/7.4/interactive/indexes-multicolumn.html
In any case, it might even be the case that the index isn't being used at all. Does anyone know if indexes are used in a case like this:
spk_tgp t JOIN spk_tgplog l ON (t.tgpid = l.tgpid)
My hunch is that it's not used. My understanding is that an index acts more as a shortcut so the database doesn't have to go through the entire table to look for specific values. When joining two tables, however, you inherently have to go through the entire table. If anyone can clarify this, that'd be great.
-- PC Drew
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