Re: Read Committed isolation

I guess the big question is whether we want to be teaching isolation
level concepts in our manual. It is a standard database concept.

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Oliver Crow wrote:
>
> Hi all,
>
> It seems to me that the PostgreSQL user's manual could be clearer on the
> consequences of using the Read Committed isolation level.
>
> It says "The partial transaction isolation provided by Read Committed
> mode is adequate for many applications" ... "However, for applications
> that do complex queries and updates, it may be necessary to guarantee a
> more rigorously consistent view of the database".
>
> It does not say what types of transactions will cause problems in Read
> Committed mode, or what the consequences of those problems might be.
> This is a point on which the manual ought to be explicit ... the potential
> for intermittent creation of database inconsistencies is serious. For
> example, if information from a select is passed via the application to an
> update, the transaction could reintroduce stale information.
>
> This message provides some good explanation with examples:
> http://archives.postgresql.org/pgsql-hackers/2002-04/msg00150.php
>
>
> It also speaks clearly about when a serializable transaction may need to
> be repeated, and the possible trade off between using serializable or
> SELECT FOR UPDATE. Could an edited version of that message be included in
> the manual? (I'd be willing to assist with editing)
>
>
> Thanks, Oliver
>
>
>
>
>
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