[ 
https://issues.apache.org/jira/browse/DERBY-3571?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12584537#action_12584537
 ] 

Thomas Nielsen commented on DERBY-3571:
---------------------------------------

The diffs you see IMHO look like the optimizer is choosing different solutions 
for the subquery flattening?

> LOB locators are not released if the LOB columns are not accessed by the 
> client
> -------------------------------------------------------------------------------
>
>                 Key: DERBY-3571
>                 URL: https://issues.apache.org/jira/browse/DERBY-3571
>             Project: Derby
>          Issue Type: Bug
>          Components: JDBC, Network Client
>    Affects Versions: 10.3.2.1, 10.4.0.0, 10.5.0.0
>            Reporter: Kristian Waagan
>            Assignee: Kristian Waagan
>             Fix For: 10.5.0.0
>
>         Attachments: derby-3571-1a-client_track_lob_fix.diff, 
> derby-3571-1a-client_track_lob_fix.stat, 
> derby-3571-1b-client_track_lob_fix.diff, 
> derby-3571-1c-client_track_lob_fix.diff, 
> derby-3571-1d-client_track_lob_fix.diff, 
> derby-3571-1e-client_track_lob_fix.diff, derby-3571-2a-simple_release.diff, 
> derby-3571-2a-simple_release.stat
>
>
> If the client creates a result set containing LOB locator columns and 
> iterates through it without actually accessing the LOB columns, the locators 
> are not released.
> The amount of locators and their associated LOB objects causes the server to 
> consume large amounts of memory and it eventually gets an OOME.
> There are a few workarounds for this bug:
>  a) Access and/or properly close the LOBs (i.e. Blob.free).
>     This is partly dependent on DERBY-2892.
>  b) Invoke Connection.commit (or rollback) periodically, which causes all 
> locators on the connection to be released.

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

Reply via email to