make LockRelation use top transaction ID
Hackers,
I just figured that if we let LockRelation use GetCurrentTransactionId()
then the wrong thing happens if we let large objects survive
subtransaction commit/abort. The problem is that when closing a large
object at main transaction commit, which was opened inside a
subtransaction, the code tries to UnlockRelation(pg_largeobject), and
use the main transaction Xid (instead of the subtransaction Xid that it
used to LockRelation()).
So I have changed it to use GetTopTransactionId() instead. Is that OK
with everybody?
--
Alvaro Herrera (<alvherre[a]dcc.uchile.cl>)
Maybe there's lots of data loss but the records of data loss are also lost.
(Lincoln Yeoh)
Alvaro Herrera <alvherre@dcc.uchile.cl> writes:
I just figured that if we let LockRelation use GetCurrentTransactionId()
then the wrong thing happens if we let large objects survive
subtransaction commit/abort.
So I have changed it to use GetTopTransactionId() instead. Is that OK
with everybody?
No, at least not if you made that a global change. Doing it that way
will mean that a failed subtransaction will not release its locks, no?
regards, tom lane
On Fri, Jul 23, 2004 at 09:49:05AM -0400, Tom Lane wrote:
Alvaro Herrera <alvherre@dcc.uchile.cl> writes:
I just figured that if we let LockRelation use GetCurrentTransactionId()
then the wrong thing happens if we let large objects survive
subtransaction commit/abort.So I have changed it to use GetTopTransactionId() instead. Is that OK
with everybody?No, at least not if you made that a global change. Doing it that way
will mean that a failed subtransaction will not release its locks, no?
Hmm ... won't they be released when the ResourceOwner is released?
--
Alvaro Herrera (<alvherre[a]dcc.uchile.cl>)
"Ni aun el genio muy grande llegar�a muy lejos
si tuviera que sacarlo todo de su propio interior" (Goethe)
Alvaro Herrera <alvherre@dcc.uchile.cl> writes:
On Fri, Jul 23, 2004 at 09:49:05AM -0400, Tom Lane wrote:
No, at least not if you made that a global change. Doing it that way
will mean that a failed subtransaction will not release its locks, no?
Hmm ... won't they be released when the ResourceOwner is released?
Er ... duh. Still stuck in pre-ResourceOwner ways of thinking ;-)
Now that I'm more awake, I recall that I actually considered changing
the lock code to take all locks in the name of the TopTransaction as
part of the ResourceOwner patch. But I decided to leave well enough
alone because I hadn't time to think about all the implications.
Yeah, if you don't see any problem, go for it.
regards, tom lane