Re: How to force Nested Loop plan? - Mailing list pgsql-performance

From Ron Johnson
Subject Re: How to force Nested Loop plan?
Date
Msg-id 1062261220.669.576.camel@haggis
Whole thread Raw
In response to Re: How to force Nested Loop plan?  (Rob Nagler <nagler@bivio.biz>)
List pgsql-performance
On Sat, 2003-08-30 at 10:47, Rob Nagler wrote:
> Tom Lane writes:
[snip]
> enough.  When I add this index, I will slow down inserts (about
> 20K/day) and increase data size (this is the second largest table in
[snip]

Since I gather that this is a web-site, can we presume that they
are clumped into an 8 hour range?  20,000/8 = 2,500/hour, which
is 41.67/minute.  If you can't do .69 inserts/second, something
is wrong, and it ain't hardware, and it ain't Postgresql...

> > PS: does server_id really need to be NUMERIC?  Why not integer, or at
> > worst bigint?
>
> It is a NUMERIC(18).  It could be a bigint.  What would be the change
> in performance of this query if we changed it to bigint?

http://www.postgresql.org/docs/7.3/static/datatype.html#DATATYPE-INT
http://www.postgresql.org/docs/7.3/static/datatype.html#DATATYPE-NUMERIC-DECIMAL

Scalars are faster than arbitrary precision types.  Small (32 bit)
scalars are faster than bit (64 bit) scalars on x86 h/w.

--
-----------------------------------------------------------------
Ron Johnson, Jr. ron.l.johnson@cox.net
Jefferson, LA USA

"Adventure is a sign of incompetence"
Stephanson, great polar explorer


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