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https://issues.apache.org/jira/browse/DERBY-3398?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13577364#comment-13577364
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Dag H. Wanvik commented on DERBY-3398:
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Uploading a patch (#4) which changes the way we check dictionary version in
NumberDataType:
On seeing values outside the old DB2 ranges that are otherwise legal (i.e. not
infinity or NaN), we check if the current dictionary level is high enough.
Iff we have an lcc (language connection context, we use that to find the
dictionary version). If not we rely on a new short field in NumberDataType
poked into the DVD at the time the value is set (ResultSret#updateXXX,
PreparedStatement#setXXX). This is a similar approach to that used by Kristian
when handling the CLOB header versioning. It seems to work, but running full
regressions now, and I'll add more tests later if we decide to use this
approach.
There are two downsides, one minor and one slightly less so:
- iff the value is outside the old limist (and only then), we some some extra
(costly?) processing to check the dictionary version.
- we have added a short member to all NumberDataType classes (increases heap
usage by 4 or 8 bytes pr value object depending on the VMs allocation strategy.)
As before, the patch relies on the patch for DERBY-5546. Another quick shows
up though; for some reason when I compile the patched source, I get an error:
it seems the compilation of the iapi.types classes trigger a compile of
EmbedResultSet, which fails, presumably since the iapi classes are compiled
with a too low source level: javac complains about not finding enough
implementations in ERS. An incremental compile of the patch works though. I'll
look into why this happens.
> Support min/max values for Java types float/double in real/double columns
> -------------------------------------------------------------------------
>
> Key: DERBY-3398
> URL: https://issues.apache.org/jira/browse/DERBY-3398
> Project: Derby
> Issue Type: Improvement
> Components: SQL
> Affects Versions: 10.4.1.3
> Reporter: Knut Anders Hatlen
> Priority: Minor
> Labels: derby_triage10_10
> Attachments: derby-3398-2.diff, derby-3398-3.diff, derby-3398-3.stat,
> derby-3398.diff, derby-3398.status
>
>
> Derby doesn't support the entire range of valid (finite) values of the Java
> primitive types double/float in columns with SQL type DOUBLE or REAL. This
> appears to be a limitation that was introduced for compatibility with DB2.
> There have been some requests on derby-user that we lift this restriction.
> The restriction is enforced by the methods normalizeREAL() and
> normalizeDOUBLE() in org.apache.derby.iapi.types.NumberDataType.
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