Main   Products   Offshore Outsourcing   Customers   Partners   ContactUs  
JDBC Databases
  HXTT Access v6.0
  HXTT Cobol v3.0
  HXTT DBF v6.0
 
  Buy Now
  Support
  Download
  Document
  FAQ
  HXTT Excel v5.0
  HXTT Paradox v6.0
  HXTT Text(CSV) v6.0
  HXTT XML v2.0
Offshore Outsourcing
Free Resources
  Firewall Tunneling
  Search Indexing Robot
  Conditional Compilation
  Password Recovery for MS Access
  Password Recovery for Corel Paradox
  Checksum Tool for MD5
  Character Set Converter
  Pyramid - Poker of ZYH
   
   
   
Heng Xing Tian Tai Ltd. of Beijing City (abbr, HXTT)

HXTT DBF
Query Optimization in HxTT
OMkar
2006-01-03 00:00:00.0
I am testing HxTT JDBC drivers for my university project. I tested the programms which came with demo package. Can anyone please explain the importance of testSQL.java programm and also I need to know how a complicated query is optimized in HxTT JDBC driver

I would highly appreciate if you can solve my question

Thanks

Happy New Year

OMkar
Re:Query Optimization in HxTT
HXTT Support
2006-01-03 00:00:00.0
>Can anyone please explain the importance of testSQL.java programm
testSQL is only used to show how to use JDBC api to execute some sqls. If you have Java and JDBC experience, you can skip that sample and use DBVisualizer, iSQL-Viewer, JBuilder's Database Pilot, SQuirreL SQL Client, DbEdit Database Utilites, and so on, to operate your data in GUI.

>I need to know how a complicated query is optimized in HxTT JDBC driver
HXTT sql parser will analyze your sql, and do many optimizations according to existent index or temporary index. For instance, it will adjust the table order of join tables, and transform your where clause, having clause, and join condition. Some where clause will be calculated as constant, some OR conditions will become IN operation(a=3 or a=4 become a in (3,4)), some AND conditions will become a condition (a=3 and b=4 become (a,b)=(3,4), a=3 and b>'abc' become (a,b)(=,>)(3,4)) to utilize compound index. All in, between.. and... can utilize index. a like 'eeee' will become a='eee', and a like 'a%' can utilize index. Sometimes it will utilize bitmap operation for condition operation. A prepared sql can be optimizsed too...



Search Key   Search by Last 50 Questions




Google
 

Email: webmaster@hxtt.com
Copyright © 1999-2017 Heng Xing Tian Tai Ltd. of Beijing City. | All Rights Reserved. | Privacy | Legal | Sitemap