From: Michael Cochez <michaelcochez@yahoo.com>
To: pgsql-docs@postgresql.org
Subject: Re: error in documentation?
Date: Mon, 24 Sep 2007 09:34:26 -0700 (PDT)
Message-ID: <138226.58158.qm@web33511.mail.mud.yahoo.com> (raw)
In-Reply-To: <1375DFC2-C35B-4B89-B26D-4031C0E14E79@macprofessionals.com>
My reasoning was :
Look to every query on a time line
savepoint 1
query 1
....
savepoint j
query j
.....
savepoint n
query n
When I release savepoint j , I think 'everythin before savepoint j is ok and safe', and so I don't need the savepoints before savepoint j anymore (cause they're save) when I do a rollback to savepoint j, I say 'everything done after savepoint j is rubbish' so I don't need the savepoints after j anymore
Lets say I release savepoint j, why wouldn't it make sense to go back to savepoint j+1, (a state after the state beeing released).
I tought of releasing a savepoint as 'everything up to that savepoint is ok, I'm not yet shure about the queries coming next'
Michael
Phil Frost <phil@macprofessionals.com> wrote:
If I do:
savepoint one;
update foo set bar = 2;
savepoint two;
update baz set foo = 3;
savepoint three;
delete from foo;
Why would it make sense to release "one" if i release "two"? If I
release "two", then it makes sense that I can never go back to "two"
or "three", but your proposed change means that if I release "two", I
can later rollback to "three" but not to "one". I don't see how
that's useful.
Essentially what the docs say is that savepoints are created on a
stack, and when you do something to to a savepoint "s", you
implicitly do the same thing to all the other savepoints above "s".
Or, if you think of them being nested:
savepoint one {
update foo set bar = 2;
savepoint two {
update baz set foo = 3;
savepoint three {
delete from foo;
...
}
...
}
...
}
then any operation on a savepoint also applies to any savepoints
nested within it.
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To: pgsql-docs@postgresql.org
Cc: michaelcochez@yahoo.com
Subject: Re: error in documentation?
In-Reply-To: <138226.58158.qm@web33511.mail.mud.yahoo.com>
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