Re: Sorting performance vs. MySQL

On Mon, Feb 22, 2010 at 2:41 PM, Frank Heikens <frankheikens(at)mac(dot)com> wrote:
>
> Op 22 feb 2010, om 20:28 heeft Yang Zhang het volgende geschreven:
>>
>>
>>>
>>>
>>>>> If your work-mem is too low there's a good chance that Postgres has to
>>>>> use your disks for sorting, which will obviously be quite slow.
>>>>
>>>> Relative to the non-terminating 80-minute-so-far sort, Unix sort runs
>>>> much faster (on the order of several minutes).
>>>
>>> Make sure your index does fit into memory, what's the size of the index?
>>
>> How might I find out the size and whether it's being fit in memory?
>
> SELECT pg_size_pretty(pg_relation_size('i_transactionid'));

pg_size_pretty
----------------
1080 MB
(1 row)
--
Yang Zhang
http://www.mit.edu/~y_z/