[ 
http://issues.apache.org/jira/browse/DERBY-326?page=comments#action_12362679 ] 

Kathey Marsden commented on DERBY-326:
--------------------------------------

I am reviewing this patch.    I am sorry for the long delay after the holidays. 
 I should be able to post comments Monday.    I am still working to understand 
the changes.

 A  few  general items 

1) Javadoc - I think it would be good to add more javadoc even with the 
briefest description of the method function and parameters.

2) Tests - You had asked at one point I think about a location for tests.  I 
think largedata/loblengthTests could be modified to use a stream and then the 
jvmflags line removed.

3) Code Formatting  - There seem to be code indentation inconsistencies in 
DDMWriter.  Also I think it is good to indent the method bodies  in the new 
methods in ReEncodedInputStream.java. Things sort of run together.


Thanks

Kathey


> Improve streaming of large objects for network server and client
> ----------------------------------------------------------------
>
>          Key: DERBY-326
>          URL: http://issues.apache.org/jira/browse/DERBY-326
>      Project: Derby
>         Type: Improvement
>   Components: Network Server, Network Client, Performance
>     Reporter: Kathey Marsden
>     Assignee: Tomohito Nakayama
>  Attachments: DERBY-326.patch, DERBY-326_2.patch, DERBY-326_3.patch, 
> DERBY-326_4.patch, DERBY-326_5.patch
>
> Currently the stream writing  methods in network server and client require a  
> length parameter. This means that we have to get the length of the stream 
> before sending it. For example in network server in EXTDTAInputStream we have 
> to use getString and getbytes() instead of getCharacterStream and 
> getBinaryStream so that we can get the  length.
> SQLAM Level 7 provides for the enhanced LOB processing to allow streaming 
> without indicating the length, so, the writeScalarStream methods in
> network server DDMWriter.java and network client Request.java can be changed 
> to not require a length.
> Code inspection of these methods seems to indicate that while the length is 
> never written it is used heavily in generating the DSS. One strange thing is 
> that it appears on error, the stream is padded out to full length with zeros, 
> but an actual exception is never sent.  Basically I think perhaps these 
> methods need to be rewritten from scratch based on the spec requirements for 
> lobs.
> After the writeScalarStream methods have been changed, then EXTDAInputStream 
> can be changed to properly stream LOBS. See TODO tags in this file for more 
> info.  I am guessing similar optimizations available in the client as well, 
> but am not sure where that code is.

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