From: | Heikki Linnakangas <hlinnaka(at)iki(dot)fi> |
---|---|
To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
Cc: | pgsql-committers(at)postgresql(dot)org |
Subject: | Re: pgsql: Fix handling of all-zero pages in SP-GiST vacuum. |
Date: | 2015-07-27 15:55:45 |
Message-ID: | 55B65481.1040100@iki.fi |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-committers |
On 07/27/2015 06:36 PM, Tom Lane wrote:
> Heikki Linnakangas <heikki(dot)linnakangas(at)iki(dot)fi> writes:
>> Fix handling of all-zero pages in SP-GiST vacuum.
>
> I'm a little bit uncomfortable with the way that this patch presumes that
> PageIsEmpty (a) is safe on an all-zeroes page and (b) will return true for
> such a page. Yes, it does work at the moment; but I don't think we are
> making such an assumption anyplace else, and in view of your other two
> concurrent patches, it doesn't seem very future-proof here either.
> I recommend that the code look more like
>
> if (!SpGistBlockIsRoot(blkno))
> {
> if (PageIsNew(page) || PageIsEmpty(page))
>
I thought I saw other places that assumed that, and I even thought I saw
a comment somewhere documenting that usage. But now that I grep around,
I see no such thing.
I'll go change that...
- Heikki
From | Date | Subject | |
---|---|---|---|
Next Message | Robert Haas | 2015-07-27 16:32:35 | Re: pgsql: Improve LWLock scalability. |
Previous Message | Heikki Linnakangas | 2015-07-27 15:55:42 | pgsql: Don't assume that PageIsEmpty() returns true on an all-zeros pag |