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From "Dag H. Wanvik (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (DERBY-532) Support deferrable constraints
Date Wed, 13 Nov 2013 21:27:24 GMT

     [ https://issues.apache.org/jira/browse/DERBY-532?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Dag H. Wanvik updated DERBY-532:
--------------------------------

    Attachment: derby-532-serializable-scan-2.stat
                derby-532-serializable-scan-2.diff

Attaching patch derby-532-serializable-scan-2. This removes the (new) btree conglomerate format
as discussed, and also adds two more test cases:

a) to testLocks we add a test to verify xact 2 must wait to insert (another) duplicate behind
xact 1
b) to testImport, we add a test case to verify that multiple rows containing a null will not
fail even for a deferred constraint.

It also adds the point on the approach & its correctness to the code in IndexChanger as
requested by Mike. Re-running regressions.


> 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: deferredConstraints.html, deferredConstraints.html, deferredConstraints.html,
deferredConstraints.html, 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-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-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-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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