Avoid unnecessary round-trip for commit/rollback in the client driver
---------------------------------------------------------------------
Key: DERBY-4653
URL: https://issues.apache.org/jira/browse/DERBY-4653
Project: Derby
Issue Type: Improvement
Components: JDBC, Network Client
Affects Versions: 10.7.0.0
Reporter: Kristian Waagan
Priority: Minor
The methods Connection.commit() and Connection.rollback() in the client driver
cause a round-trip to the server even if the commit/rollback is unnecessary
(i.e. there is nothing to commit or roll back).
Comments suggest (see below) that this can be optimized, such that the commands
are flowed to the server only when required. It can be seen that this
optimization has been used other places in the client driver. Never the less,
it must be checked that this optimization doesn't have side-effects.
This issue came up in connection with connection pooling, where a pool
implementation always issued a rollback to make sure there was no active
transaction on the connection handed out.
>From Connection.flowCommit:
// Per JDBC specification (see javadoc for Connection.commit()):
// "This method should be used only when auto-commit mode has been
disabled."
// However, some applications do this anyway, it is harmless, so
// if they ask to commit, we could go ahead and flow a commit.
// But note that rollback() is less harmless, rollback() shouldn't be
used in auto-commit mode.
// This behavior is subject to further review.
// if (!this.inUnitOfWork)
// return;
// We won't try to be "too smart", if the user requests a commit, we'll
flow a commit,
// regardless of whether or not we're in a unit of work or in
auto-commit mode.
//
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
