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From "Rick Hillegas (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (DERBY-5235) Remove the artificial limit on the length of VARCHAR values, allowing them to be java.lang.Integer.MAX_VALUE long
Date Tue, 17 May 2011 14:20:47 GMT

    [ https://issues.apache.org/jira/browse/DERBY-5235?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13034779#comment-13034779
] 

Rick Hillegas commented on DERBY-5235:
--------------------------------------

Thanks for the quick comments, Knut. Cloudscape was able to index VARCHAR columns. The Cloudscape
limitation was that an index key could not be longer than half the page size of the index.
There was a compile-time check for CREATE INDEX and a run-time check for INSERT/UPDATE. We
would want to make sure that indexes don't break if you lengthen a VARCHAR column using ALTER
TABLE ALTER COLUMN. Don't remember if there were failures when a sort spilled to disk for
an ORDER BY on a beefy VARCHAR. These limitations need to be tested and the behavior documented
as part of picking up this issue.

I agree that if we lift this limit on the length of VARCHAR, then it will look pretty silly
when LONG VARCHAR is shorter than VARCHAR. Thanks.

> Remove the artificial limit on the length of VARCHAR values, allowing them to be java.lang.Integer.MAX_VALUE
long
> -----------------------------------------------------------------------------------------------------------------
>
>                 Key: DERBY-5235
>                 URL: https://issues.apache.org/jira/browse/DERBY-5235
>             Project: Derby
>          Issue Type: Improvement
>          Components: SQL
>    Affects Versions: 10.9.0.0
>            Reporter: Rick Hillegas
>
> The original Cloudscape limit for the length of VARCHAR values was java.lang.Integer.MAX_VALUE.
That is the limit in Cloudscape 5.1. Nothing in Derby should break if we restore the original
limit. The current limit is an artificial bound introduced to make Derby agree with DB2. 32672
is the upper bound on the length of a DB2 VARCHAR: http://publib.boulder.ibm.com/infocenter/db2luw/v8/index.jsp?topic=/com.ibm.db2.udb.doc/admin/r0001029.htm

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