Re: JDBC gripe list (the autocommit subthread)

On 1 April 2011 10:34, Quartz <quartz12h(at)yahoo(dot)com> wrote:

> You have been defending all that long that most use the autocommit=false when using batches. Then they won't break....!
>
> Besides that's what release notes are for. And I dare say, if they expected a transaction when using a batch with autocommit=true, it about time they learn their mistake. JDBC api is a contract. Can't make exception for postgres.

The JDBC spec says that the behavior of executeBatch() with
autocommit=true is implementation defined, and specifically warns
against using it with autocommit on.

I don't see any problems with the driver's current behavior:

(a) it would be quite a lot of extra work to wrap each statement in a
separate transaction (we'd have to send explicit BEGIN/END around each
statement execution;
(b) the current behavior is consistent with how multiple statement
execution works elsewhere in the driver, where if you execute "SELECT
a; SELECT b" as a statement with autocommit=true then the two queries
run in a single transaction;
(c) usually batch updates are there for performance reasons, which is
at odds with creating a separate transaction for each batched
statement;
(d) the current behavior *is* allowed by the specification.

The problem is with your code relying on particular behavior of
executeBatch() + autocommit, which the spec explicitly warns is
implementation-defined behavior that you shouldn't rely on.

Oliver