Re: Best way to scan on-disk bitmaps - Mailing list pgsql-hackers

From Victor Y. Yegorov
Subject Re: Best way to scan on-disk bitmaps
Date
Msg-id 20050512212701.GB18096@mits.lv
Whole thread Raw
In response to Re: Best way to scan on-disk bitmaps  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Best way to scan on-disk bitmaps  (Tom Lane <tgl@sss.pgh.pa.us>)
List 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 bitmapON (a, b, c)
will the planner pick an index scan forWHERE 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


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