[ http://issues.apache.org/jira/browse/DERBY-1676?page=all ]

Sunitha Kambhampati updated DERBY-1676:
---------------------------------------

    Description: 
Please see solution #3 proposed in DERBY-1661 notes. 
http://issues.apache.org/jira/secure/attachment/12338618/1661_Notes.txt

Currently, the max number of open files for a merge phase is 512.  Worst case, 
the sort module can keep 512 open files per connection during the merge phase.  
It seems that we should be able to dynamically change the max merge runs. 

Even though the 512 limit is there, it is very much possible to hit the too 
many file descriptor limit given other files open on the system. One 
interesting solution would be to catch the FileNotFoundException that gets 
thrown when during the scan , when an error happens on  opening the merge run 
file and dynamically change the max_merge_runs to accommadate this.  

This jira is to investigate this issue.

More improvements are possible in the sort module, see derby-1661


  was:
Please see solution #3 proposed in DERBY-1660 notes. 
http://issues.apache.org/jira/secure/attachment/12338618/1661_Notes.txt

Currently, the max number of open files for a merge phase is 512.  Worst case, 
the sort module can keep 512 open files per connection during the merge phase.  
It seems that we should be able to dynamically change the max merge runs. 

Even though the 512 limit is there, it is very much possible to hit the too 
many file descriptor limit given other files open on the system. One 
interesting solution would be to catch the FileNotFoundException that gets 
thrown when during the scan , when an error happens on  opening the merge run 
file and dynamically change the max_merge_runs to accommadate this.  

This jira is to investigate this issue.

More improvements are possible in the sort module, see derby-1660.



> Dynamically change the max merge runs in a merge phase during external 
> sorting.
> -------------------------------------------------------------------------------
>
>                 Key: DERBY-1676
>                 URL: http://issues.apache.org/jira/browse/DERBY-1676
>             Project: Derby
>          Issue Type: Improvement
>          Components: Store
>    Affects Versions: 10.0.2.0, 10.0.2.1, 10.1.1.0, 10.2.0.0, 10.1.2.1, 
> 10.1.3.0, 10.1.3.1
>            Reporter: Sunitha Kambhampati
>
> Please see solution #3 proposed in DERBY-1661 notes. 
> http://issues.apache.org/jira/secure/attachment/12338618/1661_Notes.txt
> Currently, the max number of open files for a merge phase is 512.  Worst 
> case, the sort module can keep 512 open files per connection during the merge 
> phase.  It seems that we should be able to dynamically change the max merge 
> runs. 
> Even though the 512 limit is there, it is very much possible to hit the too 
> many file descriptor limit given other files open on the system. One 
> interesting solution would be to catch the FileNotFoundException that gets 
> thrown when during the scan , when an error happens on  opening the merge run 
> file and dynamically change the max_merge_runs to accommadate this.  
> This jira is to investigate this issue.
> More improvements are possible in the sort module, see derby-1661

-- 
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators: 
http://issues.apache.org/jira/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira

        

Reply via email to