Message-ID: <1248.219.65.233.8.1051117946.squirrel@mail.trade-india.com>
Date: Wed, 23 Apr 2003 22:42:26 +0530 (IST)
Subject: Re: Why is seq search preferred here by planner?
From: <mallah@trade-india.com>
To: <josh@agliodbs.com>
In-Reply-To: <200304231000.20578.josh@agliodbs.com>
References: <1220.219.65.235.51.1051114881.squirrel@mail.trade-india.com>
	<200304231000.20578.josh@agliodbs.com>
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Cc: <pgsql-sql@postgresql.org>
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> Mallah,
>
>> UPDATE email_bank set country=3Dpersonal_account_details.country where u=
serid
>> > 0 and userid=3Dpersonal_account_details.userid  ;
>
> While Postgres is letting you "fudge", you are missing part of that SQL  =
statement.  It should
> be:
>
> UPDATE email_bank set country=3Dpersonal_account_details.country
> FROM personal_account_details
> where userid > 0 and userid=3Dpersonal_account_details.userid  ;

yes this is the proper SQL , but that also works and have same results.

>
>> tradein_clients=3D# begin work;explain analyze UPDATE email_bank set
>> country=3Dpersonal_account_details.country where userid > 0 and
>> userid=3Dpersonal_account_details.userid  ;BEGIN
>> Time: 669.57 ms
>
> Hmmm ... 669 ms seems pretty speedy for updating 150,000 rows.   What's t=
he  problem?

Hmm i am not running postgresql on a CRAY  :-)

 that was the time for "begin work;"  since
i am explain analysing an update i am putting it in transaction.

the actualt time was nearing 300 secs which is 5 mins

i did an explain of the UPDATE FROM variant of the query it has the same
plan for it.

regds
mallah.


>
> --
> Josh Berkus
> Aglio Database Solutions
> San Francisco


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