Re: 2-phase commit - Mailing list pgsql-hackers

From Zeugswetter Andreas SB SD
Subject Re: 2-phase commit
Date
Msg-id 46C15C39FEB2C44BA555E356FBCD6FA4962036@m0114.s-mxs.net
Whole thread Raw
In response to 2-phase commit  (Andrew Sullivan <andrew@libertyrms.info>)
List pgsql-hackers
I was wondering whether we need to keep WAL online for 2PC,
or whether only something like clog is sufficient.

What if:1. phase 1 commit must pass the slave xid that will be used for 2nd phase   (it needs to return some sort of
identificationanyway)2. the coordinator must keep a list of slave xid's along with    corresponding (commit/rollback)
info

Is that not sufficient ? Why would WAL be needed in the first place ?
This is not replication, the slave has it's own WAL anyway.

I also don't buy the argument with the lockup. Iff today somebody connects
with psql starts a transaction modifies something and then never commits
or aborts there is also no automatism builtin that will eventually kill
it automatically. 2PC will simply need to have means for the administrator
to rollback/commit an in doubt transaction manually.

Andreas


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