All this is well and good, but inside a function you might not see data that is committed since the query snapshot is not updated within a function. Search on setQuerySnapshot in the pgsql-bugs list and I think you'll find more info. So far no one has come up with the evidence needed to convince the core developers to change this behavior.
Robert Treat On Sun, 2004-01-25 at 13:09, Andrew Biagioni wrote: > In the v7.3 docs: > > http://www.postgresql.org/docs/7.3/interactive/transaction-iso.html#XACT > -READ-COMMITTED > <http://www.postgresql.org/docs/7.3/interactive/transaction-iso.html#XAC > T-READ-COMMITTED> > > Read Committed is the default isolation level in PostgreSQL. When a > transaction runs on this isolation level, a SELECT query sees only data > committed before the query began; it never sees either uncommitted data > or changes committed during query execution by concurrent transactions. > (However, the SELECT does see the effects of previous updates executed > within its own transaction, even though they are not yet committed.) In > effect, a SELECT query sees a snapshot of the database as of the instant > that that query begins to run. Notice that two successive SELECTs can > see different data, even though they are within a single transaction, if > other transactions commit changes during execution of the first SELECT. > > Andrew > > V i s h a l Kashyap @ [Sai Hertz And Control Systems] wrote: > > > Dear Oliver Elphick , > > > If I am not wrong PostgreSQL select statements works on committed data > > thus the new > > inserted data at #3 must not be available to sai_func_b() till #5 > > > > > > No. All operations by a single transaction are visible inside the > > transaction. Therefore an encapsulated function can see anything already > > done in the whole transaction. A function must be entirely inside a > > transaction and cannot start a transaction, so there can never be any > > problem about this. > > > > Loads of thanks for the kind reply . > Would be greatefull if you kindly post some links/refrences to support > your answer for the said. > Thanks one again . > > > > -- > > Regards, > > Vishal Kashyap > > > > ~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~* > > I Know you believe my words so logon to Jabber.org > > and add [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> to > your roster. > > OR > > Seek Me at 264360076 > > ~*~*~*~*~*~*~*~* > > I am usually called as Vishal Kashyap > > but my Girlfriend calls me as Vishal CASH UP. > > This is because others identify me because of my generosity > > but my Girlfriend identify me because of my CASH. > > ~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~*~* > > > -- Build A Brighter Lamp :: Linux Apache {middleware} PostgreSQL ---------------------------(end of broadcast)--------------------------- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
