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https://issues.apache.org/jira/browse/DERBY-6003?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Knut Anders Hatlen updated DERBY-6003:
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Attachment: d6003-3c-downgrade-with-stored-proc.diff
I wasn't quite happy with the approach in the 3b patch either, as I didn't like
having to expose the clearSPSPlans() method in the DataDictionary interface
just for the tests.
So I went back and tried to find out why the new
SYSCS_INVALIDATE_STORED_STATEMENTS procedure didn't do the trick. The procedure
calls SPSDescriptor.makeInvalid() on all the SPSs in SYS.SYSSTATEMENTS. That
method sets the VALID to false in the system table, but the actual plan is left
there.
The procedure could potentially help with more bugs if it also cleared the
plan. The statement is going to be recompiled on the next execution anyways, so
there's no value in keeping the plan in the system table.
The attached patch d6003-3c-downgrade-with-stored-proc.diff implements that
approach and makes SPSDescriptor.makeInvalid() change both the VALID column and
the CONSTANTSTATE column (which holds the plan). It adds the same workaround to
the upgrade tests as the 3b patch, only that it calls
SYSCS_INVALIDATE_STORED_STATEMENT instead of DataDictionary.clearSPSPlans().
The patch makes the upgrade tests run cleanly in combination with the 4a patch.
It has the following advantages over the 3b patch:
- No new interface methods in the DataDictionary
- It makes SYSCS_INVALIDATE_STORED_STATEMENT useful for a larger class of bugs
> Create row templates outside of the generated code
> --------------------------------------------------
>
> Key: DERBY-6003
> URL: https://issues.apache.org/jira/browse/DERBY-6003
> Project: Derby
> Issue Type: Improvement
> Components: SQL
> Affects Versions: 10.10.0.0
> Reporter: Knut Anders Hatlen
> Assignee: Knut Anders Hatlen
> Priority: Minor
> Attachments: d6003-1a-cleanup.diff, d6003-2a-unused-field.diff,
> d6003-3a-safe-downgrade.diff, d6003-3b-downgrade-workaround-in-tests.diff,
> d6003-3c-downgrade-with-stored-proc.diff, d6003-4a-scanresultset.diff
>
>
> The constructors for many of the result set classes take GeneratedMethod
> parameters that create row templates (an ExecRow of a certain size and column
> types, each column initialized to an SQL null value).
> As an alternative, the compiler could produce an ExecRow instance and put it
> into the savedObjects field of GenericPreparedStatement, and the constructors
> could take parameter that points to the object in savedObjects. Where the
> result sets currently invoke the generated method to produce a fresh
> template, they could instead clone the saved object.
> Advantages with the suggested approach would be:
> - Reduce the size of the code generator, which should reduce total code
> complexity.
> - Reduce the amount of generated code, which makes it easier for tools
> (profilers, static code analyzers, IDEs) to map executable code to source
> code.
> - Reduce the actual number of generated methods, which makes it less likely
> that queries need to use reflection to invoke the remaining generated methods
> (there's a switchover from DirectCall to ReflectCall when the number of
> generated methods exceeds 10).
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