I was spending some time investigating how to fix the jdbc driver to
deal with the autocommit functionality in 7.3. I am trying to come up
with a way of using 'set autocommit = on/off' as a way of implementing
the jdbc symantics for autocommit. The current code just inserts a
'begin' after every commit or rollback when autocommit is turned off in
jdbc.
I can continue to use the old way and just issue a 'set autocommit = on'
at connection initialization, but I wanted to investigate if using 'set
autocommit = off' would be a better implementation.
The problem I am having is finding a way to turn autocommit on or off
without generating warning messages, or without having the change
accidentally rolled back later.
Below is the current behavior (based on a fresh pull from cvs this morning):
Key: ACon = autocommit on ACoff = autocommit off NIT = not in transaction IT = in transaction IT*
=in transaction where a rollback will change autocommit state
Current State Action End State
ACon and NIT set ACon ACon and NIT set ACoff ACoff and IT*
ACon and IT set ACon ACon and IT set ACoff ACoff and IT*
ACon and IT* set ACon ACon and IT* set ACoff ACoff and IT
ACoff and NIT set ACon ACon and NIT set ACoff ACoff and IT
ACoff and IT set ACon ACon and IT* set ACoff ACoff and IT
ACoff and IT* set ACon ACon and IT set ACoff ACoff and IT*
There are two conclusions I have drawn from this:
1) Without the ability for the client to know the current transaction
state it isn't feasible to use set autocommit = on/off in the client.
There will either end up being spurious warning messages about
transaction already in process or no transaction in process, or
situations where a subsequent rollback can undo the change. So I will
stay with the current functionality in the jdbc driver until the FE/BE
protocol provides access to the transaction status.
2) In one place the current functionality doesn't make sense (at least
to me).
ACon and NIT set ACoff ACoff and IT*
If I am running in autocommit mode and I issue a command I expect that
command to be committed. But that is not the case here. I would have
expected the result to be: ACoff and NIT
thanks,
--Barry