Re: [HACKERS] Sequential scan speed, mmap, disk i/o - Mailing list pgsql-hackers

From Bruce Momjian
Subject Re: [HACKERS] Sequential scan speed, mmap, disk i/o
Date
Msg-id 199805141454.KAA09189@candle.pha.pa.us
Whole thread Raw
In response to Re: [HACKERS] Sequential scan speed, mmap, disk i/o  (dg@illustra.com (David Gould))
Responses Re: [HACKERS] Sequential scan speed, mmap, disk i/o  (dg@illustra.com (David Gould))
List pgsql-hackers
> Very interesting. Is it possible to get the schema, the query, and a
> a sample of the data or a generator program for the data? I am quite surprised
> to see us do so well, I would have guess that the per row overhead would
> have us down far below wc.

Sure.

    create table test (x1 int, x2 int, x3 char(10), x4 varchar(50));
    insert into test values (3, 8, 'asdf','asdf');

    insert into test select * from test;  <- continue until test is large

    select * from test where x1 = 23423; <- this is what I timed


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