Re: Best way to scan on-disk bitmaps
Victor Yegorov <viy@mits.lv>
From: "Victor Y. Yegorov" <viy@mits.lv>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Postgres Hackers <pgsql-hackers@postgresql.org>
Date: 2005-05-12T21:27:01Z
Lists: pgsql-hackers
* Tom Lane <tgl@sss.pgh.pa.us> [12.05.2005 23:09]: > 1. Be sure that all the indexable WHERE conditions are passed to the > indexscan as indexquals. This might be, say, > WHERE a = 42 and b = 'foo' If I have on-disk bitmap ON (a, b, c) will the planner pick an index scan for WHERE a = 42 AND b = 'foo' (i.e. only part of the index attributes are involved)? Any modifications needed to achieve this functionality? To my mind, bitmap scan even for 1 attribute of a multi-column index would be a win, though I haven't tested this yet. -- Victor Y. Yegorov