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From "Dag H. Wanvik (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (DERBY-532) Support deferrable constraints
Date Wed, 06 Nov 2013 15:52:18 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-unique-pk-3.status
                derby-532-xa-3.status
                derby-532-xa-3.diff
                derby-532-import-3.diff
                derby-532-import-3.status
                derby-532-unique-pk-3.diff

Uploading refreshed versions of the three uncommitted (apply in sequential order to build):
{noformat}
derby-532-unique-pk-3.diff
derby-532-xa-3.diff
derby-532-import-3.diff
{noformat}

Also attaching a new patch, derby-532-more-tests-1, which

{quote}
adds more tests and changes the representation of the duplicates we store away in the hash
table, so omit a unique counter and the row location of th eoriginal row, since none of those
are actually used, so the has table can be reduced in size - we do not need to *store* all
duplicates, just the key (once).  
{quote}

Apply on top of the three first ones, 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-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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