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From "vodarus vodarus" <voda...@gmail.com>
Subject Re: Speed of using Derby DB
Date Mon, 16 Jun 2008 10:11:34 GMT
> PS:
>> It *may* be that the reason for the slow execution is outdated index
>> cardinality statistics. Check out "CALL
>> SYSCS_UTIL.SYSCS_INPLACE_COMPRESS_TABLE" either on nabble or in the derby
>> docs.
>>
>
> Vodarus,
>
> Did you get around to try out the tip from Thomas?
>
> If you first create the index and then load the data, the statistics can be
> badly outdated. If you first created the table, loaded the data and finally
> created the index you should be fine though.
>
> Just curious, as we have seen reports of severe performance degradations
> because of this issue, which causes the optimizer to choose a bad plan.
>
> regards,
>
Hello.

I created example of application. All app merged into one file. All in this
topic can run app and get the same results.

final private WORK_TYPE work_type should be set to DATA_FROM_SCRATCH at
first run.
Than use DATA_DROP_AND_CREATE for recreating data or DATA_USE_OLD to use old
data.

Anyone can use app and get the same results as i. I am interested in high
speed of calculateTotalStored or calculateTotalClient methods ONLY!!!


PS this app for testing purposes only, so code re-usability and other things
like it are not important.

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