Re: [HACKERS] Re: create index updates nrows statistics

From: Bruce Momjian <maillist(at)candle(dot)pha(dot)pa(dot)us>
To: ZEUGSWETTER Andreas IZ5 <Andreas(dot)Zeugswetter(at)telecom(dot)at>
Cc: "'hackers(at)postgresql(dot)org'" <hackers(at)postgreSQL(dot)org>
Subject: Re: [HACKERS] Re: create index updates nrows statistics
Date: 1999-05-27 00:10:29
Message-ID: 199905270010.UAA14780@candle.pha.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

I had this patch, but was unsure if it was save for 6.5.

Looks like Tom has decided. Good.

> > a create index updates the statistics in pg_class,
> > this leads to substantial performance degradation compared to
> > 6.4.2.
> >
> > If you want to see what I mean simply run the performance test in
> > our test subdirectory.
> >
> > I think the create index statement should not update this statistic.
> > (at least not in the newly created empty table case)
> > This behavior would then be in sync with the create table behavior.
> >
> To fix this I urgently suggest the following patch:
> <<index.patch>>
> regression passes and is a little faster :-)
> performance test: without patch 7min now 22 sec
>
> Andreas

[Attachment, skipping...]

--
Bruce Momjian | http://www.op.net/~candle
maillist(at)candle(dot)pha(dot)pa(dot)us | (610) 853-3000
+ If your life is a hard drive, | 830 Blythe Avenue
+ Christ can be your backup. | Drexel Hill, Pennsylvania 19026

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Tom Lane 1999-05-27 00:40:58 Re: [HACKERS] report for Win32 port
Previous Message Bruce Momjian 1999-05-27 00:09:47 Re: [HACKERS] Uh-oh II - ecpg