| From: | Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> |
|---|---|
| To: | Peter Geoghegan <pg(at)bowt(dot)ie> |
| Cc: | PostgreSQL Hackers <pgsql-hackers(at)postgresql(dot)org>, "Wood, Dan" <hexpert(at)amazon(dot)com> |
| Subject: | Re: [COMMITTERS] pgsql: Fix freezing of a dead HOT-updated tuple |
| Date: | 2017-10-04 12:06:09 |
| Message-ID: | 20171004120609.kuf2wtyu6osdfpxm@alvherre.pgsql |
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| Lists: | pgsql-committers pgsql-hackers |
Alvaro Herrera wrote:
> Peter Geoghegan wrote:
>
> > I thought that we no longer store FrozenTransactionId (xid 2) as our
> > "raw" xmin while freezing, and yet that's what we see here.
>
> I'm doing this in 9.3. I can't tell if the new tuple freezing stuff
> broke things more thoroughly, but it is already broken in earlier
> releases.
In fact, I think in 9.3 we should include this patch, to set the Xmin to
FrozenXid. 9.4 and onwards have commit 37484ad2a "Change the way we
mark tuples as frozen" which uses a combination of infomask bits, but in
9.3 I think leaving the unfrozen value in the xmax field is a bad idea
even if we set the HEAP_XMAX_COMMITTED bit.
--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
| Attachment | Content-Type | Size |
|---|---|---|
| fix-multi-freezing.patch | text/plain | 522 bytes |
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