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https://issues.apache.org/jira/browse/DERBY-5235?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13038631#comment-13038631
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Rick Hillegas commented on DERBY-5235:
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Continuing the discussion of what our character types might be:
The SQL distinction between VARCHAR and CLOB might map naturally onto the Java
distinction between Strings and character streams. Java Strings are limited to
Integer.MAX_VALUE characters. Character streams have unbounded length.
This distinction, of course, doesn't make sense in Derby today. A Derby CLOB is
limited to Integer.MAX_VALUE characters even though java.sql.Clob supports up
to Long.MAX_VALUE characters. Probably a substantial amount of work would be
needed to support CLOBs longer than Integer.MAX_VALUE.
If we adopted this approach, we could give users the following advice:
LONG VARCHAR - Deprecated. Supported for backward compatibility.
VARCHAR - Use this type if you won't exceed Integer.MAX_VALUE characters.
Corresponds to java.lang.String.
CLOB - Use this type if you need more than Integer.MAX_VALUE characters.
Corresponds to java.io.Reader.
Implications of this approach would include:
o We would maintain the current (SQL Standard) behavior of not supporting CLOBs
in sorts and foreign keys.
o We would want to support the Standard by allowing = and <> to operate on
CLOBs (see DERBY-5241).
o We would want to support indexes on long VARCHARs and otherwise handle them
efficiently.
> 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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