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HXTT DBF
HXTT DBF Driver takes long time to search data in DBF
Devika Hinge
2013-06-12 03:46:26.0
Hello Support Team,

I have currently downloaded HXTT DBF Driver 4.0 version and in the evaluation period. We are potentially looking at buying a full licensed version as it seems to fit most of our needs. But, I wanted to quickly check following thing with your team first - We have a very large DBF file which is around 190 MB and it has CDX index files defined. If I query this dbf through Java program using a PreparedStatement (query uses ORDER BY ) . It is taking more than a minute to fetch the data.How this search can be improved?

Thanks in advance,

Devika
Re:HXTT DBF Driver takes long time to search data in DBF
HXTT Support
2013-06-12 06:08:03.0
>It is taking more than a minute to fetch the data.How this search can be improved?
ORDER BY need external sort, a bigger maxCacheSize connection property can reduce or avoid disk file swap.

>We have a very large DBF file which is around 190 MB
If you're using "select * from atable order by column1", If there's an index on column1, HXTT DBF can utilize it for ORDER BY clause.

If your ORDER sql has a where clause, and HXTT DBF will try to utilize index for your sql.

If your where clause hasn't a matched index file, but you use a bigger delayedClose connection property, HXTT DBF will utilize automatic temporary index to quicken it.

Re:Re:HXTT DBF Driver takes long time to search data in DBF
Devika
2013-06-13 04:00:02.0
Dear Support Team,

Thanks for the prompt response. As p the guidelines provided - the WHERE caluse did have coumns which were a part of the index dfined on the dbf.But, there are multiple indexes defined for this dbf.

I then tried setting the delayedClose property to 15 and the time was reduced down to 20 sec, which is certainly a good sign.

Would there be any (positive / negative) implications / side-effects of setting the delayedClose property for the connection? Is it absolutely 'safe' to set this property while establishing a connection? Is there any suggested optimal value to be set?

Thanks,
Devika
Re:Re:Re:HXTT DBF Driver takes long time to search data in DBF
HXTT Support
2013-06-13 05:48:03.0
>Is it absolutely 'safe' to set this property while establishing a connection?
It's safe.

>the time was reduced down to 20 sec,
It's too slow still . Please let us know your sql sample, and what index expression on that table.
Re:Re:Re:Re:HXTT DBF Driver takes long time to search data in DBF
Devika
2013-06-14 02:15:57.0
Dear Support Team,

The dbf has in all 8 columns (say column 1 , ... column 8 ) and it has 4 indexes (.CDX ) defined on it. Also, to mention it has a date field as one of it's columns, (col6).

The indexes are as follows :

1. col1, col2, col3,col4,dtos(col6), col7
2. col1, col2,dtos(col6), col7
3. col1,dtos(col6), col7, col2
4. col3,col4,col5,col8

The SQL Query is a Java PreparedStatement as follows:

select col8 from where col1= ? AND col2 = ? AND col3 = ? AND col4= ? AND col5 = ? order by col6 desc

Kindly advise how the search can further be improved.

Thanks & Regards,
Devika
Re:Re:Re:Re:Re:HXTT DBF Driver takes long time to search data in DBF
HXTT Support
2013-06-14 02:36:55.0
>The indexes are as follows :
>1. col1, col2, col3,col4,dtos(col6), col7
>2. col1, col2,dtos(col6), col7
>3. col1,dtos(col6), col7, col2
>4. col3,col4,col5,col8
Your index expression are
1. col1+col2+col3+col4+dtos(col6)+col7
2. col1+col2+dtos(col6)+col7
3. col1+dtos(col6)+col7+col2
4. col3+col4+col5+col8
?
Re:Re:Re:Re:Re:Re:HXTT DBF Driver takes long time to search data in DBF
Devika
2013-06-14 02:40:30.0
Your index expression are
1. col1+col2+col3+col4+dtos(col6)+col7
2. col1+col2+dtos(col6)+col7
3. col1+dtos(col6)+col7+col2
4. col3+col4+col5+col8
?

Yes, Thanks for correction. The indexes are as above (with + and not with , as mentioned in my previous email)

Regards,
Devika
Re:Re:Re:Re:Re:Re:Re:HXTT DBF Driver takes long time to search data in DBF
Devika
2013-06-17 04:45:28.0
Dear Support Team,

Is there any update on this please?

Thanks in advance,

Regards,
Devika
Re:Re:Re:Re:Re:Re:Re:Re:HXTT DBF Driver takes long time to search data in DBF
HXTT Support
2013-06-17 06:24:59.0
col1+col2+col3+col4+dtos(col6)+col7 is not standard component index, which is supported by HXTT Access, HXTT Cobol, and HXTT Paradox. We will provide a similar solution for it in this week.
Re:Re:Re:Re:Re:Re:Re:Re:HXTT DBF Driver takes long time to search data in DBF
Devika
2013-06-17 06:26:55.0
Great. That's brilliant. Will await for the further follow-up.

Regards,
Devika
Re:Re:Re:Re:Re:Re:Re:Re:HXTT DBF Driver takes long time to search data in DBF
Devika
2013-06-21 07:05:22.0
Dear Support Team,

Is there any news? Kindly advise.

Thanks & Regards,
Devika
Re:Re:Re:Re:Re:Re:Re:Re:HXTT DBF Driver takes long time to search data in DBF
HXTT Support
2013-06-25 06:41:09.0
Please wait more 3 day. It's coding.
Re:Re:Re:Re:Re:Re:Re:Re:HXTT DBF Driver takes long time to search data in DBF
Devika
2013-06-25 07:07:29.0
Great. Thanks.

Re:Re:Re:Re:Re:Re:Re:Re:HXTT DBF Driver takes long time to search data in DBF
HXTT Support
2013-06-29 01:31:41.0
Supported now.
Re:Re:Re:Re:Re:Re:Re:Re:HXTT DBF Driver takes long time to search data in DBF
Devika
2013-07-01 05:56:27.0
Dear Support Team,

This is a great news. Can you please let me know where can I download the new vesion? Is there any other config setting that needs to be done?

Regards,
Devika
Re:Re:Re:Re:Re:Re:Re:Re:HXTT DBF Driver takes long time to search data in DBF
HXTT Support
2013-07-01 06:08:37.0
Download JDBC3.0 package from http://www.hxtt.com/dbf.zip or login in to download more.
Re:Re:Re:Re:Re:Re:Re:Re:HXTT DBF Driver takes long time to search data in DBF
Devika
2013-07-02 05:11:39.0
Dear Support Team,


First of all , thanks for the prompt reply. We have now purchased the product :). I have downloaded the DBF_JDBC40.jar and using this jar in the Project path , but I am now encountered with a ClassCastException as follows:

java.sql.SQLException: java.lang.ClassCastException: com.hxtt.e.k cannot be cast to com.hxtt.sql.o

Am I using the right jar ? Can you please help me out.

Regards,
Devika
Re:Re:Re:Re:Re:Re:Re:Re:HXTT DBF Driver takes long time to search data in DBF
Devika
2013-07-02 05:30:38.0
Re-sending the email ..

Dear Support Team,


First of all , thanks for the prompt reply. We have now purchased the product :). I have downloaded the DBF_JDBC40.jar and using this jar in the Project path , but I am now encountered with a ClassCastException as follows:

java.sql.SQLException: java.lang.ClassCastException: com.hxtt.e.k cannot be cast to com.hxtt.sql.o

Am I using the right jar ? Can you please help me out.

Regards,
Devika
Re:Re:Re:Re:Re:Re:Re:Re:HXTT DBF Driver takes long time to search data in DBF
HXTT Support
2013-07-02 06:16:07.0
Please use e.printStackTrace();
to print the detailed message.
Re:Re:Re:Re:Re:Re:Re:Re:HXTT DBF Driver takes long time to search data in DBF
Devika
2013-07-02 06:50:59.0
Dear Support Team,

Please find the complete error stack as follows:

java.sql.SQLException: java.lang.ClassCastException: com.hxtt.e.k cannot be cast to com.hxtt.sql.o
at com.hxtt.sql.ah.a(Unknown Source)
at com.hxtt.sql.ah.a(Unknown Source)
at com.hxtt.sql.ah.if(Unknown Source)
at com.hxtt.sql.dbf.i.if(Unknown Source)
at com.hxtt.sql.a5.a(Unknown Source)
at com.hxtt.sql.d4.a(Unknown Source)
at com.hxtt.sql.d4.a(Unknown Source)
at com.hxtt.sql.d4.a(Unknown Source)
at com.hxtt.sql.df.a(Unknown Source)
at com.hxtt.sql.bz.a(Unknown Source)
at com.hxtt.sql.am.a(Unknown Source)
at com.hxtt.sql.am.a(Unknown Source)
at com.hxtt.sql.am.executeQuery(Unknown Source)
at com.dlr.jcar.car.service.impl.MSLDataProviderServiceImpl.getOrderInfo(MSLDataProviderServiceImpl.java:132)
at com.dlr.jcar.car.core.CARProcessHandler.startCARProcess(CARProcessHandler.java:91)
at com.dlr.jcar.car.core.CARProcessHandler.main(CARProcessHandler.java:43)

at com.hxtt.global.SQLState.SQLException(Unknown Source)
at com.hxtt.sql.bz.a(Unknown Source)
at com.hxtt.sql.am.a(Unknown Source)
at com.hxtt.sql.am.a(Unknown Source)
at com.hxtt.sql.am.executeQuery(Unknown Source)
at com.dlr.jcar.car.service.impl.MSLDataProviderServiceImpl.getOrderInfo(MSLDataProviderServiceImpl.java:132)
at com.dlr.jcar.car.core.CARProcessHandler.startCARProcess(CARProcessHandler.java:91)
at com.dlr.jcar.car.core.CARProcessHandler.main(CARProcessHandler.java:43)

Regards,
Devika
Re:Re:Re:Re:Re:Re:Re:Re:HXTT DBF Driver takes long time to search data in DBF
HXTT Support
2013-07-02 08:11:22.0
Supported. Please redownload it.
Re:Re:Re:Re:Re:Re:Re:Re:HXTT DBF Driver takes long time to search data in DBF
Devika
2013-07-02 08:37:44.0
Hello,

I have downloaed the latest jar. Class Cast Exception seems to have been resolved , but the following error appears:

The prepared Statement I am trying to execute is as follows:

select from where = 'MSN' AND = AND = AND = AND = order by desc

java.sql.SQLException: Failed to get a string value from com.hxtt.e.f: MSN
at com.hxtt.global.SQLState.SQLException(Unknown Source)
at com.hxtt.global.SQLState.transferValueException(Unknown Source)
at com.hxtt.global.ak.int(Unknown Source)
at com.hxtt.sql.dbf.i.a(Unknown Source)
at com.hxtt.sql.a7.a(Unknown Source)
at com.hxtt.sql.ah.a(Unknown Source)
at com.hxtt.sql.cw.a(Unknown Source)
at com.hxtt.sql.a5.a(Unknown Source)
at com.hxtt.sql.d4.a(Unknown Source)
at com.hxtt.sql.d4.a(Unknown Source)
at com.hxtt.sql.d4.a(Unknown Source)
at com.hxtt.sql.d4.if(Unknown Source)
at com.hxtt.sql.d4.a(Unknown Source)
at com.hxtt.sql.d4.a(Unknown Source)
at com.hxtt.sql.d4.a(Unknown Source)
at com.hxtt.sql.bz.a(Unknown Source)
at com.hxtt.sql.bz.a(Unknown Source)
at com.hxtt.sql.bz.a(Unknown Source)
at com.hxtt.sql.am.a(Unknown Source)
at com.hxtt.sql.d6.executeQuery(Unknown Source)
at com.dlr.jcar.car.service.impl.MSLDataProviderServiceImpl.findMSLOrderForBoxID(MSLDataProviderServiceImpl.java:41)
at com.dlr.jcar.car.core.CARProcessHandler.startCARProcess(CARProcessHandler.java:68)
at com.dlr.jcar.car.core.CARProcessHandler.main(CARProcessHandler.java:43)

Can you please advise.

Regards,
Devika
Re:Re:Re:Re:Re:Re:Re:Re:HXTT DBF Driver takes long time to search data in DBF
Devika
2013-07-03 04:47:56.0
Hello guys,

Just wanted to confirm whether you received above logged error. Any update regarding this would be highly appreciated.

Many Thanks,
Devika
Re:Re:Re:Re:Re:Re:Re:Re:HXTT DBF Driver takes long time to search data in DBF
Devika
2013-07-04 02:40:34.0
Dear Support Team,

Any update on above if it is been looked at? Your response would be greatly appreciated.

Regards,
Devika
Re:Re:Re:Re:Re:Re:Re:Re:HXTT DBF Driver takes long time to search data in DBF
HXTT Support
2013-07-04 06:51:32.0
Supported yesterday.
Re:Re:Re:Re:Re:Re:Re:Re:HXTT DBF Driver takes long time to search data in DBF
Devika
2013-07-05 08:19:10.0
Dear Support Team,

Thank you very much. I tried with the latest jar and now the query brings back the data just in a sec. Excellent.

-Regards,
Devika

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