agora inbox for postgres@postgres.berkeley.edu  

help / color / mirror / Atom feed

From: Kai Petzke <wpp@marie.physik.tu-berlin.de>
To: William T. Smith <smith_w@mcnc.org>
Cc: postgres@postgres.Berkeley.EDU
Subject: Re: POSTGRES Append Performance
Date: Fri, 13 Jan 1995 01:42:19 +0100 (MET)
Message-ID: <9501130040.AA07751@marie.physik.tu-berlin.de> (raw)
In-Reply-To: <199501121907.OAA07712@robin.mcnc.org.mcnc.org>

> 
> Hello,
> 
> 	I am evaluating version 4.2 of POSTGRES as a database tool to
> provide persistent storage of directed graphs.  The test program adds
> one node which requires 17 append operations against an empty database.
> Each instance has less than 100 bytes.  The program takes 10 seconds
> elapsed time to execute.  Adding ten nodes takes 20 seconds.  Is this
> "normal" performance for POSTGRES?  Does anyone have any suggestions to
> improve performance? Is anyone using POSTGRES to support interactive
> applications.

Postgres has the overhead of all RDBMS systems: it has to parse the
queries, then optimize then, then do the actual work.  While doing
the first steps, tons of tuples are accessed from the pg_* files
of your database.

If you want better update performance for multiple tuples, use the 
"copy in" function.  Here, the parsing is done only once for the
complete set, not once for every datum.




Kai


==============================================================================
   To add/remove yourself to/from the POSTGRES mailing list: send mail with 
   the subject line ADD or DEL to "postgres-request@postgres.Berkeley.EDU".
   If this fails, send mail to "post_questions@postgres.Berkeley.EDU" and
   a human will deal with it.  DO NOT post to the "postgres" mailing list.
==============================================================================
              URL: http://s2k-ftp.CS.Berkeley.EDU:8000/postgres/

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: postgres@postgres.berkeley.edu
  Cc: wpp@marie.physik.tu-berlin.de, smith_w@mcnc.org
  Subject: Re: POSTGRES Append Performance
  In-Reply-To: <9501130040.AA07751@marie.physik.tu-berlin.de>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox