Performance of a Query : which one is giving good performace

Question

Post reply

Performance of a Query : which one is giving good performace

Raghu.K

SSC Veteran

Points: 286
More actions
December 28, 2012 at 3:45 am

#286731

Hi Please help me...
I want join 4 tables in the Oracle.Table 1 is having 4 different where conditions.
Which one is better (Performance wise)
1.Join all 4 tables and write table1 where conditions globally (After Joining 4 tables)
2.Make Table1 as Derived Table with all where conditions and joining with 3 tables.
Please help me

Viewing 5 posts - 1 through 4 (of 4 total)

You must be logged in to reply to this topic. Login to reply

Gail Shaw SSC Guru Points: 1004504 More actions · Answer 1

Test them and see?

Alternately, maybe ask on an Oracle forum where you're more likely to get an answer.

Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

We walk in the dark places no others will enter
We stand on the bridge and no one may pass

Jo Pattyn SSC-Dedicated Points: 32347 More actions · Answer 2

Can't tell much without actually seeing it. I had success using orafaq[/url], just be sure you read the forum guide. Do you have a testcase (create table, insert data, select query,query plan)?

nick.mcdermaid Hall of Fame Points: 3809 More actions · Answer 3

Generally speaking (as this is a general question), probably Option 1 as it lets Oracle pick the best way of applying predicates. Under limited circumstances, option 2 will limit the way in which it applies predicates.

Ask a general question get a general answer.

PaulB-TheOneAndOnly SSC Guru Points: 66772 More actions · Answer 4

Raghu.K (12/28/2012)
I want join 4 tables in the Oracle.Table 1 is having 4 different where conditions.
Which one is better (Performance wise)
1.Join all 4 tables and write table1 where conditions globally (After Joining 4 tables)
2.Make Table1 as Derived Table with all where conditions and joining with 3 tables.

Not much to work with.

Assuming you have the right indexes on place, test both cases. Since this is an Oracle question I would suggest to trace/tkprof both solutions then look at buffer_gets on both of them, usually the solution with the less buffer_gets would be the one that would perform the better.

Hope this helps.

_____________________________________
Pablo (Paul) Berzukov

Author of Understanding Database Administration available at Amazon and other bookstores.

Disclaimer: Advice is provided to the best of my knowledge but no implicit or explicit warranties are provided. Since the advisor explicitly encourages testing any and all suggestions on a test non-production environment advisor should not held liable or responsible for any actions taken based on the given advice.