On 11/1/2010 12:37 PM, Jonathan Tripathy wrote:
Hi Everyone, I'm trying to create a server for a database system which will be used by multiple clients. Of course, table locking is very important. Reading the Postgresql docs, locking occurs on a transaction-by-transaction basis. In our java code, we are doing this: //Start Code Block Connection con = "..." con.setAutoComitt(false); //Insert SQL here to lock table String qry1 = "..." pst1 = con.prepareStatement(qry1) //Insert code here to add values to prepared statement pst1 pst1.executequery(); String qry2 = "..." pst2 = con.prepareStatement(qry2) //Insert code here to add values to prepared statement pst2 pst2.executequery(); con.comitt(); //End Code Block My question is, would the above block of code be classed as a single transaction, and would the locking work correctly? Thanks Jonny
Table locking is very bad for concurrent access. When a table is locked, its one user at a time.
PG usually does not need any locks at all. As long as you use transactions as they were meant to be used (as an atomic operation), things usually work really well, with no locking at all. You could read up on MVCC is you were interested.
Without knowing what sql you are running, I can _totally guarantee_ it'll work perfectly with NO table locking. :-)
-Andy -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
