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https://issues.apache.org/jira/browse/DERBY-5294?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Mamta A. Satoor updated DERBY-5294:
-----------------------------------

    Issue Type: Improvement  (was: Task)

> Triggers created prior to 10.9 release will continue to read all the columns 
> from trigger table even after database has been upgraded to 10.9 and higher
> --------------------------------------------------------------------------------------------------------------------------------------------------------
>
>                 Key: DERBY-5294
>                 URL: https://issues.apache.org/jira/browse/DERBY-5294
>             Project: Derby
>          Issue Type: Improvement
>          Components: SQL
>    Affects Versions: 10.7.1.1
>            Reporter: Mamta A. Satoor
>
> With DERBY-1482 (which went in 10.9 codeline), triggers will read only the 
> columns needed by the triggering sql and firing triggers. But this applies 
> only to triggers created in 10.9 and higher. Any triggers created prior to 
> 10.9 will not be able to take advantage of DERBY-1482 because those triggers 
> do not keep the information about the trigger action columns. Currently, the 
> users will have to drop and recreate the triggers which use the REFERENCING 
> CLAUSE and were created prior to 10.9 to take advantage of DERBY-1482.
> The alternative to manual drop and recreate of such triggers can be explored 
> as part of this jira. Couple options are
> 1)UPDATE sql should detect that the trigger does not have information about 
> the trigger action columns and hence it should make the trigger collect that 
> information.
> 2)At the time of upgrade, when we mark all the SPSes invalid, detect the 
> triggers which do not have the information about the trigger action columns 
> and make those triggers collect that information.
> 3)Enhance ALTER TABLE COMPRESS to detect the triggers which do not have the 
> information about the trigger action columns and make those triggers collect 
> that information. With this option, users will still have to manually do 
> ALTER TABLE COMPRESS to fix the triggers but atleast they won't have to get 
> the original trigger definitions and drop and recreate the triggers using 
> those original trigger definitions.
> 10.9 currently does not have central place where the trigger will go and 
> collect the information about trigger action columns. We do have code in 
> ALTER TABLE DROP COLUMN to collect the trigger action column info but it will 
> probably better to have such a code in TriggerDescriptor so it can be used by 
> the approach taken to fix this jira.
> Note that without the fix for this jira, the triggers created prior to 10.9 
> will work just fine after upgrade to 10.9 and higher but they will not be 
> able to prevent reading of columns that are not necessary for the triggering 
> sql and firing triggers

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