db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Rick Hillegas (JIRA)" <j...@apache.org>
Subject [jira] Updated: (DERBY-481) implement SQL generated columns
Date Thu, 23 Oct 2008 22:48:44 GMT

     [ https://issues.apache.org/jira/browse/DERBY-481?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Rick Hillegas updated DERBY-481:
--------------------------------

    Attachment: derby-481-02-aa-utilities.diff

Attaching derby-481-02-aa-utilities.diff. This patch adds some small, miscellaneous support
which will be turned on in later patches. Regression tests pass cleanly for me. Touches the
following files:

M      java/engine/org/apache/derby/iapi/util/StringUtil.java

Added utility routine to stringify an int array.


M      java/engine/org/apache/derby/loc/messages.xml
M      java/shared/org/apache/derby/shared/common/reference/SQLState.java

New error messages related to generated columns.


M      java/testing/org/apache/derbyTesting/functionTests/tests/lang/GeneratedColumnsTest.java

A number of new test cases. New test cases are commented out right now but will be uncommented
as we check in the functionality that they verify.


> implement SQL generated columns
> -------------------------------
>
>                 Key: DERBY-481
>                 URL: https://issues.apache.org/jira/browse/DERBY-481
>             Project: Derby
>          Issue Type: New Feature
>          Components: SQL
>    Affects Versions: 10.0.2.1
>            Reporter: Rick Hillegas
>            Assignee: Rick Hillegas
>         Attachments: derby-481-00-aa-prototype.diff, derby-481-01-aa-catalog.diff, derby-481-02-aa-utilities.diff,
GeneratedColumns.html
>
>
> Satheesh has pointed out that generated columns, a SQL 2003 feature, would satisfy the
performance requirements of Expression Indexes (bug 455). Generated columns may not be as
elegant as Expression Indexes, but they are easier to implement. We would allow the following
new kind of column definition in CREATE TABLE and ALTER TABLE statements:
>     columnName GENERATED ALWAYS AS ( expression )
> If expression were an indexableExpression (as defined in bug 455), then we could create
indexes on it. There is no work for the optimizer to do here. The Language merely has to compute
the generated column at INSERT/UPDATE time.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message