Re: does database shut down cleanly when WAL device fails? - Mailing list pgsql-general

From Tom Lane
Subject Re: does database shut down cleanly when WAL device fails?
Date
Msg-id 8989.1115132728@sss.pgh.pa.us
Whole thread Raw
In response to does database shut down cleanly when WAL device fails?  (Brandon Craig Rhodes <brandon@rhodesmill.org>)
Responses Re: does database shut down cleanly when WAL device fails?
List pgsql-general
Brandon Craig Rhodes <brandon@rhodesmill.org> writes:
>       And the disputed point:

>         - If the drive holding the WAL fails, then the database engine
>           will shut down cleanly by writing everything in RAM out to
>           the real database tables, and no data will be lost.

Whoever claimed that has no familiarity with the code at all, and no
understanding of the basic WAL rule: write to the log BEFORE you write
data.

In point of fact, loss of the WAL drive will mean a database PANIC stop
and probably a corrupt data area afterwards, since there'd be no
guarantee that related page updates had all made it to disk.

            regards, tom lane

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