hai,

as mentioned above...
script to '/temp/backup.sql'; 

Backup the original database, then deleted it. 

Connect to the same database connection (it will created a new empty 
database). 

Then do something like this: 

  runscript from '/temp/backup.sql'; 

*As mentioned above i tried the same procedure but *iam getting like this
Result: Out of memory.; SQL statement:
SCRIPT 
[90108-169]<https://192.168.123.109:8082/tools.do?jsessionid=284983806554205066d2fb253968fbf3#>90108/90108
 
(Help) <http://h2database.com/javadoc/org/h2/constant/ErrorCode.html#c90108>
thanks in advance...




On Wednesday, December 31, 2008 9:30:08 AM UTC+5:30, Brish wrote:
>
> On Dec 30, 10:31 am, Peter W <[email protected]> wrote: 
> > Some questions: 
> > -Any way to reduce the table and index size? 90% overhead = lots of I/ 
> > O 
>
> H2 doesn't shrink the data, or index files so it's possible there is 
> empty space in it. Did you delete and/or update a lot of records after 
> the original insert? If not that you probably won't be able to reduce 
> the size. 
>
> If you have done a lot of updates/deletes you can do a script to like 
> this: 
>
>   script to '/temp/backup.sql'; 
>
> Backup the original database, then deleted it. 
>
> Connect to the same database connection (it will created a new empty 
> database). 
>
> Then do something like this: 
>
>   runscript from '/temp/backup.sql'; 
>
> That will rebuild the entire database so there shouldn't be a lot of 
> empty space in it. 
>
> > -Does table fragmentation affect query speed? Can tables be 
> > defragmented? 
>
> Yes it affects the performance. 
>
> You can't defrag a database but you can rebuild it using the above 
> method. 
>
> > -Other hints to improve execution speed (e.g. "partitioning" by 
> > item_id)? 
>
> Try putting "explain" in front of your query to see what h2 is doing. 
>
> You might want to try to analyze the database. That helps sometimes. 
>
> You might also want to try to change the order of the primary key so 
> that created is first, and item_id is second. 
>
> H2 is slow for large queries. If the query returns a lot of values 
> there isn't anything you can do to speed it up. 
>
> Brish 
>

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