Re: autonomous transactions

On Wed, Jan 23, 2008 at 05:50:02PM -0500, Tom Lane wrote:

Simon Riggs <simon@2ndquadrant.com> writes:

From looking at how Oracle does them, autonomous transactions are

completely independent of the transaction that originates them -- they

take a new database snapshot. This means that uncommitted changes in the

originating transaction are not visible to the autonomous transaction.

Oh! Recursion depth would need to be tested for as well. Nasty.

Seems like the cloning-a-session idea would be a possible implementation

path for these too.

Oracle has a feature where you can effectively save a session and return

to it. For example, if filling out a multi-page web form, you could save

state in the database between those calls. I'm assuming that they use

that capability for their autonomous transactions; save the current

session to the stack, clone it, run the autonomous transaction, then

restore the saved one.