Re: firebird X postgresql 8.1.2 windows, performance comparison - Mailing list pgsql-performance

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Subject Re: firebird X postgresql 8.1.2 windows, performance comparison
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Msg-id op.s55ait13cigqcu@apollo13
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In response to Re: firebird X postgresql 8.1.2 windows, performance comparison  (Carlos Henrique Reimer <carlosreimer@yahoo.com.br>)
List pgsql-performance

> I hope tomorrow execute explain with the bitmapscan and seqscan enabled.
> bitmapscans are almost always faster?

    Like all the rest, they're just a tool, which works great when used in
its intended purpose :

    - Fetching just a few percent of the rows from a table is better served
by an index scan
    - Fetching a lot of rows (>30-50%) from a table is better served by a seq
scan
    - Bitmap scan comes in between and it's a very welcome addition.

    Also Bitmap scan will save your life if you have complex searches, like
if you run a dating site and have an index on blondes and an index on boob
size, because it can use several indexes in complex AND/OR queries.

    Common wisdom says simpler databases can be faster than postgres on
simple queries.

    Reality check with pg 8.1 driven by PHP :

- SELECT 1
    mysql 5    ~ 42 us
    postgres    ~ 70 us

- SELECT * FROM users WHERE id=1
    mysql 5    ~ 180 us
    postgres    ~  160 us

    Of course people doing stupid things, like using the database to keep a
hit counter on their website which is updated on every hit, will say that
postgres is slow.

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