On Jun 11, 9:20 pm, rohithr...@[EMAIL PROTECTED]
wrote:
> On Jun 12, 4:33 am, Florian Weimer <f...@[EMAIL PROTECTED]
> wrote:
>
> > > Am a fresher in BerkeleyDB. If i open a database file(using
> > > transaction) for put(adding to DB) and if i tried to open the same
> > > file in different transaction the put is hanging. It seems a
deadlock
> > > is occuring. Is it not allowed, the same database file to be opened
in
> > > more than one transactions?
>
> > It's allowed, but only if the threads or processes executing the open
> > and the put are ordered in some way unknown to Berkeley DB. If you've
> > got a single process that tries to do these things, they are trivially
> > ordered, so it's not allowed. Another source of orderings is IPC.
>
> Thanks. My concern is in a single process.
>
> The number of database files in not defined in my work.
> So i think I need to use a single transaction in my process. Will it
> be OK to open more than 1 database files in a single transaction?
It's okay, but probably not your best bet. Why not open each database
in
its own transaction (use autocommit flag so you don't even have to
manage
the transaction). The only reasons I know to keep a transaction going
past the end of the open would be 1) you are creating your set of
databases atomically and you want the behavior where either all your
databases were created or none. or 2) performance - you are opening
1000 databases, I'd guess you'd see an open using a single transaction
to be faster then separate transactions. Same advice goes for your
original question if I understand it. Open the database in its own
separate transaction (use autocommit), and then do puts in their own
transaction. That's the typical approach anyway.
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