Re: Slow performance on MAX(primary_key) - Mailing list pgsql-sql

Hi Keith:

--- Keith Gray <keith@heart.com.au> wrote:
> Help,
> 
> I have just been comparing some large table
> performance
> under 7.1 using the
> 
>     select max(primary key)from table;
> 
> We are using this for various functions including
> sequence.
> 
 Try using the following as alternative :  SELECT primary_key FROM table ORDER BY primary_key desc LIMIT 1;
 This should work if primary_key is indexes.
 As of now, Max() doesn't utilizes the indices hence
it always do a sequential scan.
 Hope that helps,

regards,
ludwig.







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