RE: Use of system indexes

> -----Original Message-----
> From: pgsql-hackers-owner@hub.org [mailto:pgsql-hackers-owner@hub.org]On
> Behalf Of Bruce Momjian
>
> I am looking at how the system indexes are used.
>
> In the past, I went through and changed all system table lookups that
> return a single value into system cache lookups.
>
> I now see several cases where we are doing heap scans of system tables,
> rather than using indexes.  There are cases that can return several
> rows, so we can't use the cache.  However, we could use index scans
> rather than heap scans.
>

[snip]

>
> I can start fixing them, but as I remember, someone was thinking of
> making heap/index scans use the same interface.  Can I get a status on
> that?
>

In my trial implementation of ALTER TABLE DROP COLUMN in command.c,
there is a trial using
systable_beginscan(),systable_endscan(),systable_getnext()
functions.
However there would better unification of system table scan.

Regards.

Hiroshi Inoue
Inoue@tpf.co.jp