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From Arindam Bhattacharjee <mr.arindam.bhattachar...@gmail.com>
Subject Re: URGENT!!! JDBC SQL query taking long time for large IN clause
Date Wed, 08 Apr 2009 16:22:39 GMT
> Lastly, are you now using Derby 10.4 for all of this work, or are
> you continuing to use 10.1?
[Arindam] I will respond to the rest of your questions ASAP. The answer to
the above question is : 10.4. I am using 10.4 now and it is significantly
better than 10.1 both during insertion and during query.

Best regards,

Arindam.

On Wed, Apr 8, 2009 at 8:06 PM, Bryan Pendleton
<bpendleton@amberpoint.com>wrote:

> problem - thanks to Knut for indicating that as a possibility. When I
>> compress the tables - the quries start performing a LOT faster!
>>
>
> Good, I'm glad to hear that you've made some good progress.
>
> Do you get a different query plan now? Or is it just that the table
> access is more efficient?
>
> Can you capture the runtime statistics information for the 30 second
> query before you compressed the tables, and for the 1.1 second query
> after you compressed the table, and compare them?
>
> You mention that you've run this query on other databases, and they
> are much faster. Can you make any observations about why that might
> be, and what they may be doing differently? For example, can you see
> if the other database is using a different query plan and let us know
> the general information about what that query plan is?
>
> Also, you mention that the query runs quite well with 100 or 500 elements
> in the IN clause, but falls down with 1000 elements in the IN clause.
> Again, I'd be interested to know how the runtime statistics information
> compares between those two cases. Is it that we using a substantially
> different query plan for the larger query? Or is there some other behavior?
>
> Lastly, are you now using Derby 10.4 for all of this work, or are
> you continuing to use 10.1?
>
> thanks,
>
> bryan
>
>

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