Jena transactions vs lock

[Qi He <he...@gmail.com>]

Hello,

When should use a lock on a dataset vs. a transaction? What about with
models? Are locks necessary then? Will there be inconsistencies when
dealing with persistent models when updating them from two separate threads?

Re: Jena transactions vs lock

[Andy Seaborne <an...@apache.org>]

On 08/03/14 16:02, Qi He wrote:
> Hello,
>
> When should use a lock on a dataset vs. a transaction? What about with
> models? Are locks necessary then? Will there be inconsistencies when
> dealing with persistent models when updating them from two separate threads?
>

Use transactions unless you want some special effect or other.

Transaction allow multiple readers AND a single writer at the same time.
Pure locking only give multiple readers OR a single writer.

And transaction are crash resistant.

If you want multiple threads inside one transaction, you then need to do 
locking as well - the thread doing the .begin must be the one to do the 
.commit./.end.

	Andy