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https://issues.apache.org/jira/browse/DERBY-4719?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12883167#action_12883167
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Rick Hillegas commented on DERBY-4719:
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Thanks for your detailed explanation of this bizarre and confusing behavior,
Kristian. I'm going to mouse in my initial comments from the email thread which
triggered this JIRA. I can imagine that this inconsistency is very frustrating
to our users.
<mousedInComments>
Each of the options you are considering will create backward compatibility
problems for some applications. I believe that silent behavior changes are
worse than noisy ones. I think that we could talk ourselves into an
incompatible behavior change if the javadoc explicitly says that the behavior
is undefined today.
However, I don't see much value in moving from one inconsistent behavior to
another. If we want to tackle this confusion, then I would recommend that we
define the behavior explicitly in the javadoc and make all of the DataSources
conform to the defined behavior.
</mousedInComments>
I think that the following behavior would be easy for users to understand if it
were consistent across all Derby DataSources:
i) The connection attribute string should be parsed by all of the DataSources
and its directives should be followed.
ii) Derby should raise an exception (or at least a warning) if an attribute is
set to an illegal value.
iii) In the case where conflicting values are specified for an attribute (e.g.,
one value is specified in the connection string and another value is specified
in an explicit setter method), then the most recent specification should
prevail.
I think that (1a) would be incremental movement toward this set of rules.
Thanks,
-Rick
> Define consistent Derby data source behavior
> --------------------------------------------
>
> Key: DERBY-4719
> URL: https://issues.apache.org/jira/browse/DERBY-4719
> Project: Derby
> Issue Type: Task
> Components: Documentation, Javadoc, JDBC, Network Client
> Affects Versions: 10.7.0.0
> Reporter: Kristian Waagan
>
> The behavior of the various data source implementations in Derby isn't
> consistent.
> As a starting point, from the thread [1] on derby-dev:
> -----
> Hi,
> I have been investigating how the various Derby data source implementations
> behave when it comes to [bean] properties.
> Properties and attributes are used interchangeably, and I'll be using the
> following abbreviations:
> o DS-[E|C] the "normal" data souce embedded/client
> o CP-[E|C] ConnectionPoolDataSource embedded/client
> o XA-[E|C] XADataSource embedded/client
> Here are some of the current issues:
> 1) CP-C and XA-C effectively ignore the connection attribute string for
> certain attributes (those who have individual setters, DERBY-4067)
> 2) *-E don't update the internal property state based on the connection
> attribute string (i.e. specifying ";user=myuser" won't change the return
> value of getUser() after connect).
> 3) Only some of the properties are updated from the connection attribute
> string. This is as expected, but it is confusing that for instance
> 'traceDirectory' is updated and 'traceLevel' isn't.
> 4) *-C has 'APP' as the default user, *-E has <null>.
> 5) Some property setters accept all values, others throw an exception if the
> value is invalid.
> I don't think all these issues should be fixed, but I'd like to fix (1), as
> it has caused some trouble in the past (i.e., user not understanding why the
> settings aren't taking effect).
> There are several possible fixes for (1):
> 1a) Make CP-C and XA-C process the connection attribute string to update the
> internal state.
> 1b) Make DS-C ignore the connection attribute string (may break existing
> deployments).
> 1c) Throw exception if a property with a setter is specified in the
> connection attribute string.
> I don't care that much about which solution is chosen, but I'd prefer that
> the various data sources are consistent. For instance, it would be nice if a
> user could swap ClientDataSource with ClientConnectionPoolDataSource without
> having to change the data source definition. For instance, doing this today
> with "ssl=basic" in the connection attribute string would make DS-C connect
> with SSL, but CP-C would connection without SSL.
> We have this wording in the JavaDoc for
> ClienBaseDataSource.setConnectionAttributes(String):
> "Set this property to pass in more Derby specific connection URL attributes.
> Any attributes that can be set using a property of this DataSource
> implementation (e.g user, password) should not be set in
> connectionAttributes. Conflicting settings in connectionAttributes and
> properties of the DataSource will lead to unexpected behaviour."
> Any opinions or questions on any of this?
> Regards,
> -----
> [1] http://old.nabble.com/Derby-data-sources-to28692616.html#a28692616
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