Re: Set new system identifier using pg_resetxlog - Mailing list pgsql-hackers

From Robert Haas
Subject Re: Set new system identifier using pg_resetxlog
Date
Msg-id CA+TgmoZXih6aiyefqAMzQ5wXkVWEQKzO+8+TFeHn3toi5z5Z4A@mail.gmail.com
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In response to Re: Set new system identifier using pg_resetxlog  (Alvaro Herrera <alvherre@2ndquadrant.com>)
Responses Re: Set new system identifier using pg_resetxlog
Re: Set new system identifier using pg_resetxlog
List pgsql-hackers
On Mon, Jun 30, 2014 at 12:46 PM, Alvaro Herrera
<alvherre@2ndquadrant.com> wrote:
> I think it's pretty much a given that pg_resetxlog is a tool that can
> have disastrous effects if used lightly.  If people changes their sysid
> wrongly, they're not any worse than if they change their multixact
> counters and start getting failures because the old values stored in
> data cannot be resolved anymore ("it's already been wrapped around").
> Or if they remove all the XLOG they have since the latest crash.  From
> that POV, I don't think the objection that "but this can be used to
> corrupt data!" has any value.

After thinking about this a little more, I guess I don't really think
it's a bit problem either - so consider my objection withdrawn.

I am, however, kind of frustrated, still, that the pg_computemaxlsn
patch, which I thought was rather a good idea, was scuttled by the
essentially that same objection: let's not extend pg_resetxlog &
friends because people might use the new functionality to do bad
things and then blame us.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company



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