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Date: Wed, 10 May 2006 21:49:05 +0000 (GMT+00:00)
From: "Daniel John Debrunner (JIRA)" <derby-dev@db.apache.org>
To: derby-dev@db.apache.org
Subject: [jira] Commented: (DERBY-684) Improve performance of Clob objects
 (ClobOutputStream#write,ClobWriter#write) on the client
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    [ http://issues.apache.org/jira/browse/DERBY-684?page=comments#action_12378981 ] 

Daniel John Debrunner commented on DERBY-684:
---------------------------------------------

Note that StringBufferInputStream is non-portable and should not be used. It will lead to different output on platforms with different default encoding, e.g. IBM z/os. See DERBY-1256

> Improve performance of Clob objects (ClobOutputStream#write,ClobWriter#write) on the client
> -------------------------------------------------------------------------------------------
>
>          Key: DERBY-684
>          URL: http://issues.apache.org/jira/browse/DERBY-684
>      Project: Derby
>         Type: Improvement

>   Components: Performance, Network Client
>     Versions: 10.2.0.0, 10.1.1.1, 10.1.1.0
>  Environment: all
>     Reporter: Sunitha Kambhampati

>
> Dan suggested this improvement  here:
> http://issues.apache.org/jira/browse/DERBY-463?page=comments#action_12356742
> For org.apache.derby.client.am.ClobOutputStream#write(int), five objects are created for every byte written.
> "In fact this class and the client Clob have code like this everywhere, as the Clob is updated:
>         clob_.string_ = clob_.string_.concat(new String(newByte));
>         clob_.asciiStream_ = new java.io.StringBufferInputStream(clob_.string_);
>         clob_.unicodeStream_ = new java.io.StringBufferInputStream(clob_.string_);
>         clob_.characterStream_ = new java.io.StringReader(clob_.string_);
> Would probably be better to create most of those objects on demand, rather than on every modification. I mean if the CLOB is modified
> but the application never retrieives the ascii  or character streams, what was the benefit of creating them? "
> ________________
> Also check the org.apache.derby.client.am.ClobWriter.  Need to make this better and efficient. 

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