Re: Hot standby and GiST page splits (was Re: WIP: Fast GiST index build)

On Mon, Aug 1, 2011 at 2:29 PM, Heikki Linnakangas
<heikki(dot)linnakangas(at)enterprisedb(dot)com> wrote:
> On 01.08.2011 14:35, Simon Riggs wrote:
>>
>> On Mon, Aug 1, 2011 at 11:44 AM, Heikki Linnakangas
>> <heikki(dot)linnakangas(at)enterprisedb(dot)com>  wrote:
>>
>>>> Does the order of locking of the buffers matter? I'm sure it does.
>>>
>>> Yep.
>>
>> Do you mean that the BlockNumbers are already in correct sequence, or
>> that you will be adding this code to redo?
>
> I just meant that yes, the order of locking of the buffers does matter.
>
> I believe we code acquire the locks in right order already, and the patch I
> posted fixes the premature release of locks at page split.

Your patch is good, but it does rely on the idea that we're logging
the blocks in the same order they were originally locked. That's a
good assumption, but I would like to see that documented for general
sanity, or just mine at least.

I can't really see anything in the master-side code that attempts to
lock things in a specific sequence, which bothers me also.

--
 Simon Riggs                   http://www.2ndQuadrant.com/
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