From: | Bruce Momjian <maillist(at)candle(dot)pha(dot)pa(dot)us> |
---|---|
To: | scldad(at)sdc(dot)com(dot)au (Stephen Davies) |
Cc: | pgsql-general(at)postgreSQL(dot)org |
Subject: | Re: [GENERAL] Limit on multi-field indexes? |
Date: | 1998-09-23 04:01:00 |
Message-ID: | 199809230401.AAA20009@candle.pha.pa.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-general |
> > > Am I correct in believing that there is a limit of seven columns in a
> > > multi-filed index?
> > >
> > > If so, is it possible to increase this limit (to at least eight) ?
> > >
> > > Cheers and thanks,
> >
> > Not easily. The columns are stored in an int28 column, that holds 8
> > two-byte integer. We would have to change that to a larger field. Very
> > few people have asked for this.
> >
> Getting desperate here.
>
> If it holds 8 integers, why can't I have 8 columns in a multi-field index?
>
> I am currently writing a tool to replicate any database to a PostgreSQL mirror
> and the very first customer for this tool has several tables with 8 fields in
> their primary key. Sod's Law:-((
There is no field in pg_index to determine the number of fields in the
index, so it scans pg_index.indkey until it hits a 0. Now, I suppose we
could change the code so it goes through indkey until it gets a 0, or
reaches the eighth entry.
--
Bruce Momjian | 830 Blythe Avenue
maillist(at)candle(dot)pha(dot)pa(dot)us | Drexel Hill, Pennsylvania 19026
http://www.op.net/~candle | (610) 353-9879(w)
+ If your life is a hard drive, | (610) 853-3000(h)
+ Christ can be your backup. |
From | Date | Subject | |
---|---|---|---|
Next Message | Bruce Momjian | 1998-09-23 04:20:49 | Re: [GENERAL] Limit on multi-field indexes? |
Previous Message | Jayvee Vibar | 1998-09-23 03:43:42 | ODBC |