Re: Why is seq search preferred here by planner?

> Mallah,
>
>> UPDATE email_bank set country=personal_account_details.country where userid
>> > 0 and userid=personal_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=personal_account_details.country
> FROM personal_account_details
> where userid > 0 and userid=personal_account_details.userid  ;

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

>
>> tradein_clients=# begin work;explain analyze UPDATE email_bank set
>> country=personal_account_details.country where userid > 0 and
>> userid=personal_account_details.userid  ;BEGIN
>> Time: 669.57 ms
>
> Hmmm ... 669 ms seems pretty speedy for updating 150,000 rows.   What's the  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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