Re: Composite types questions

2010/1/11 Merlin Moncure :
> On Mon, Jan 11, 2010 at 11:08 AM, Vincenzo Romano > SELECT * FROM master_tab
>>  WHERE col1>='a date':timestamp AND col1<'another date'::timestamp
>> AND col2=42 AND col3='the answer';
>
> queries of this sort are optimally handled via row constructor for 8.2 onwards:
>
> create index col231_idx  on master_tab(col2, col3, col1);
>
> select * from master_tab where (col2,col3,co1) >= (42, 'the answer',
> a_date) and (col2,col3,co1) < (42, 'the answer', b_date);
>
> one caveat: the planner is lousy in regards to estimating index
> selectivity in these cases which can cause strange behaviors.
>
> regarding constraint_exclusion, I don't think there are any
> issues...you should test it to be sure.
>
> merlin
>

Great news for me!
Thanks Merlin ... the Wizard!  :-)


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