db-derby-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Kristian Waagan (JIRA)" <j...@apache.org>
Subject [jira] Updated: (DERBY-3825) StoreStreamClob.getReader(charPos) performs poorly
Date Thu, 28 Aug 2008 12:39:44 GMT

     [ https://issues.apache.org/jira/browse/DERBY-3825?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Kristian Waagan updated DERBY-3825:
-----------------------------------

    Attachment: derby-3825-1a-reset_readpositioninbuffer.diff

'derby-3825-1a-reset_readpositioninbuffer.diff' is a small cleanup patch moving the resetting
of the readPositionInBuffer variable into fillBuffer.

Committed to trunk with revision 689803.

> StoreStreamClob.getReader(charPos) performs poorly
> --------------------------------------------------
>
>                 Key: DERBY-3825
>                 URL: https://issues.apache.org/jira/browse/DERBY-3825
>             Project: Derby
>          Issue Type: Bug
>          Components: JDBC, Store
>    Affects Versions: 10.5.0.0
>            Reporter: Kristian Waagan
>         Attachments: derby-3825-0a-preview.diff, derby-3825-1a-reset_readpositioninbuffer.diff
>
>
> StoreStreamClob.getReader(charPos) performs poorly because it resets the underlying stream
and skips data until it reached the requested character position. Not only does the data has
to be skipped, it also has to be decoded (UTF-8).
> The problem is exposed through EmbedClob.getSubString, which causes extremely bad performance
for the client driver because the locator based Clob implementation uses this method.
> For the record, there is another read buffer size issue that exaggerates the problem
(it will probably be handled under DERBY-3769, and also DERBY-3818).

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message