From: Divakar Singh <dpsmails@yahoo.com>
To: Alex Hunsaker <badalex@gmail.com>
Cc: Steve Singer <ssinger@ca.afilias.info>
Cc: jd@commandprompt.com
Cc: pgsql-performance@postgresql.org
Subject: Re: Postgres insert performance and storage requirement compared to Oracle
Date: Wed, 27 Oct 2010 20:08:53 -0700 (PDT)
Message-ID: <604758.88084.qm@web65414.mail.ac4.yahoo.com> (raw)
In-Reply-To: <AANLkTi=0PkVscoYkMn-nETn16LAL4N-C8jzwGWffn7uV@mail.gmail.com>
References: <132275.30531.qm@web65411.mail.ac4.yahoo.com>
<AANLkTi=0PkVscoYkMn-nETn16LAL4N-C8jzwGWffn7uV@mail.gmail.com>
So another question pops up: What method in PostgreSQL does the stored proc use
when I issue multiple insert (for loop for 100 thousand records) in the stored
proc?
It takes half the time compared to the consecutive "insert" using libpq.
In the backend, does it use COPY or prepared statement? or something else?
Best Regards,
Divakar
________________________________
From: Alex Hunsaker <badalex@gmail.com>
To: Divakar Singh <dpsmails@yahoo.com>
Cc: Steve Singer <ssinger@ca.afilias.info>; jd@commandprompt.com;
pgsql-performance@postgresql.org
Sent: Thu, October 28, 2010 1:15:06 AM
Subject: Re: [PERFORM] Postgres insert performance and storage requirement
compared to Oracle
On Wed, Oct 27, 2010 at 08:00, Divakar Singh <dpsmails@yahoo.com> wrote:
> I am attaching my code below.
> Is any optimization possible in this?
> Do prepared statements help in cutting down the insert time to half for this
> kind of inserts?
In half? not for me. Optimization possible? Sure, using the code you
pasted (time ./a.out 100000 <method>):
PQexec: 41s
PQexecPrepared: 36s
1 insert statement: 7s
COPY: 1s
psql: 256ms
Basically the above echoes the suggestions of others, use COPY if you can.
Find the source for the above attached. Its just a very quick
modified version of what you posted. [ disclaimer the additions I
added are almost certainly missing some required error checking... ]
[ psql is fast because the insert is really dumb: insert into aaaa (a,
b, c, d, e, f, g, h, j, k, l, m, n, p) select 1, 'asdf', 'asdf',
'asdf', 'asdf', 'asdf', 'asdf', 'asdf', 'asdf', 'asdf', 'asdf',
'asdf', 'asdf', 'asdf' from generate_series(1, 100000); ]
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To: pgsql-performance@postgresql.org
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Subject: Re: Postgres insert performance and storage requirement compared to Oracle
In-Reply-To: <604758.88084.qm@web65414.mail.ac4.yahoo.com>
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