Re: Index scan optimization

On 22 September 2014 14:46, Heikki Linnakangas <hlinnakangas@vmware.com> wrote:
> On 09/22/2014 04:45 PM, Tom Lane wrote:
>>
>> Heikki Linnakangas <hlinnakangas@vmware.com> writes:
>>>
>>> On 09/22/2014 07:47 AM, Rajeev rastogi wrote:
>>>>
>>>> So my proposal is to skip the condition check on the first scan key
>>>> condition for every tuple.
>>
>>
>>> The same happens in a single-column case. If you have a query like
>>> "SELECT * FROM tbl2 where id2 > 'a'", once you've found the start
>>> position of the scan, you know that all the rows that follow match too.
>>
>>
>> ... unless you're doing a backwards scan.
>
>
> Sure. And you have to still check for NULLs. Have to get the details right..

And also that the tests don't use volatile functions.

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