[
https://issues.apache.org/jira/browse/DERBY-4653?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Lily Wei updated DERBY-4653:
----------------------------
Attachment: ReproTransInProgressAttempt.java
Thanks to Kathey. I got to know more in turn of why Connection.close() after
Connection.flowrollback() will cause error "Cannot close a connection while a
transaction is still active" for StatementPoolingTest. As the
ReproTransInProgressAttempt.java shows, if we have commit between we are in
ResultSet, we should not flowrollback. If flowrollback remains unchanged, it
will detect the state of the statement and resultSet and keep all the flag as
inUnitOfWork etc in the right place and Connection.close() will not run into
error as "Cannot close a connection while a transaction is still active".
Due to this reason, I am leading toward to not fix flowrollback() to save round
trip and just keep the change for flowcommit() to improve performance.
> 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
> Assignee: Lily Wei
> Priority: Minor
> Attachments: _sds_0, DERBY-4653-1.diff, DERBY-4653-2.diff,
> DERBY-4653-3_withrollback.diff, DERBY-4653-4_withcommitrollbacktest.diff,
> DERBY-4653-5_withflowcommitrollback.diff,
> DERBY-4653-6_withflowcommitrollback.diff, ReproTransInProgressAttempt.java,
> SaveRoundClientDS.java, SaveRoundClientDS.java
>
>
> 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.
