Re: Avoiding unnecessary reads in recovery

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От Tom Lane
Тема Re: Avoiding unnecessary reads in recovery
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Msg-id 6236.1177537782@sss.pgh.pa.us
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Ответ на Re: Avoiding unnecessary reads in recovery  (Heikki Linnakangas <heikki@enterprisedb.com>)
Ответы Re: Avoiding unnecessary reads in recovery  (Heikki Linnakangas <heikki@enterprisedb.com>)
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Heikki Linnakangas <heikki@enterprisedb.com> writes:
> Tom Lane wrote:
>> but it'd make it safe to use in non-WAL contexts (I think there are
>> other places where we know we are going to init the page and so a
>> physical read is a waste of time).

> Is there? I can't think of any. Extending a relation doesn't count.

No, but re-using a free page in an index does.  I'm not sure which index
AMs know for sure the page is free, and which have to read it and check,
but I think there's at least some scope for that.
        regards, tom lane


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