Re: Page at a time index scan - Mailing list pgsql-patches

From Tom Lane
Subject Re: Page at a time index scan
Date
Msg-id 16436.1146668216@sss.pgh.pa.us
Whole thread Raw
In response to Re: Page at a time index scan  (Simon Riggs <simon@2ndquadrant.com>)
Responses Re: Page at a time index scan  (Simon Riggs <simon@2ndquadrant.com>)
List pgsql-patches
Simon Riggs <simon@2ndquadrant.com> writes:
> On Tue, 2006-05-02 at 15:35 -0400, Tom Lane wrote:
>> This is unnecessary and probably wrong.

> You'll need to be more specific about what you mean.

There is no point in marking a page half-dead, as that doesn't save
anyone else from visiting it, and it's probably wrong to mark a leaf
page as half-dead at all.  That state is associated with upper pages.

Even if it were a legal tree configuration, marking the page half-dead
would make it impossible to insert any more keys in the page, which
doesn't strike me as an appropriate behavior; it's likely to force
excess I/O later due to unnecessary page splits during future inserts.

            regards, tom lane

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