[jira] [Comment Edited] (DERBY-532) Support deferrable constraints

["Dag H. Wanvik (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/DERBY-532?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13925765#comment-13925765 ] 

Dag H. Wanvik edited comment on DERBY-532 at 3/10/14 2:42 PM:
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Hi Rick, 
thanks for looking at the patch.

Uploading version 2, {color:blue}derby-532-check-constraints-2{color}. This adds the comments you requested as well as some minor refactoring to simplify code in lcc a bit.
As for ValidateCheckConstraintResultSet it is used in normal operation (not only for debugging). What was the wording that made you think so?


was (Author: dagw):
Hi Rick, 
thanks for looking at the patch.

Uploading version 2, {color:blue}derby-532-check-constraints-2{color}. This adds the comments you requested.
As for ValidateCheckConstraintResultSet it is used in normal operation (not only for debugging). What was the wording that made you think so?

> Support deferrable constraints
> ------------------------------
>
>                 Key: DERBY-532
>                 URL: https://issues.apache.org/jira/browse/DERBY-532
>             Project: Derby
>          Issue Type: Improvement
>          Components: SQL
>            Reporter: Jörg von Frantzius
>            Assignee: Dag H. Wanvik
>              Labels: derby_triage10_11
>         Attachments: IndexDescriptor.html, IndexDescriptorImpl.html, IndexRowGenerator.html, SortObserver.html, deferredConstraints.html, deferredConstraints.html, deferredConstraints.html, deferredConstraints.html, deferredConstraints.html, derby-532-allow-pk-unique-1.diff, derby-532-allow-pk-unique-1.status, derby-532-check-constraints-1.diff, derby-532-check-constraints-1.stat, derby-532-check-constraints-2.diff, derby-532-check-constraints-2.stat, derby-532-fix-drop-not-nullable.diff, derby-532-fix-drop-not-nullable.status, derby-532-fix-metadata-1.diff, derby-532-fix-metadata-1.status, derby-532-import-1.diff, derby-532-import-1.status, derby-532-import-2.diff, derby-532-import-3.diff, derby-532-import-3.status, derby-532-more-tests-1.diff, derby-532-more-tests-1.stat, derby-532-nullableUniqueFix.diff, derby-532-nullableUniqueFix.status, derby-532-post-scan-1.diff, derby-532-post-scan-1.stat, derby-532-post-scan-2.diff, derby-532-post-scan-2.stat, derby-532-post-scan-3.diff, derby-532-post-scan-3.stat, derby-532-post-scan-4.diff, derby-532-post-scan-4.stat, derby-532-serializable-scan-1.diff, derby-532-serializable-scan-2.diff, derby-532-serializable-scan-2.stat, derby-532-syntax-binding-dict-1.diff, derby-532-syntax-binding-dict-1.status, derby-532-syntax-binding-dict-2.diff, derby-532-syntax-binding-dict-2.status, derby-532-syntax-binding-dict-all-1.diff, derby-532-test-speedup.diff, derby-532-test-speedup.status, derby-532-test-with-default-deferrable-all-over.diff, derby-532-testAlterConstraintInvalidation.diff, derby-532-testAlterConstraintInvalidation.status, derby-532-unique-pk-1.diff, derby-532-unique-pk-1.status, derby-532-unique-pk-2.diff, derby-532-unique-pk-3.diff, derby-532-unique-pk-3.status, derby-532-upgrade-1.diff, derby-532-upgrade-1.status, derby-532-upgrade-1b.diff, derby-532-xa-1.diff, derby-532-xa-2.diff, derby-532-xa-3.diff, derby-532-xa-3.status
>
>
> In many situations it is desirable to have constraints checking taking place only at transaction commit time, and not before. If e.g. there is a chain of foreign key constraints between tables, insert statements have to be ordered to avoid constraint violations. If foreign key references are circular, the DML has to be split into insert statements and subsequent update statements by the user.
> In other words, with deferred constraints checking, life is much easier for the user. Also it can create problems with softwares such as object-relational mapping tools that are not prepared for statement ordering and thus depend on deferred constraints checking.



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