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From "Kristian Waagan (JIRA)" <j...@apache.org>
Subject [jira] Created: (DERBY-4661) Reduce size of encoding buffer for short character values
Date Fri, 14 May 2010 11:54:43 GMT
Reduce size of encoding buffer for short character values

                 Key: DERBY-4661
                 URL: https://issues.apache.org/jira/browse/DERBY-4661
             Project: Derby
          Issue Type: Improvement
          Components: JDBC
    Affects Versions:
         Environment: Inserts using setXStream(int, Reader/InputStream, int/long) for short
values on character columns
            Reporter: Kristian Waagan
            Assignee: Kristian Waagan
            Priority: Minor

When inserting character values Derby converts from Java char to an on-disk encoding of UTF-8.
To to this, the user stream is read and the resulting bytes after conversion are placed in
a "translation buffer". The default size of the buffer is 32 KB. When inserting a lot of short
values, the pressure on the Java garbage collector is unnecessary high and the allocation/GC
also causes a somewhat higher CPU usage.

This effect of this issue can easily be reduced by sizing the buffer in the appropriate cases.

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