|
|
|
|
| Re: Selection of driving table [message #307188 is a reply to message #307178] |
Tue, 18 March 2008 01:56   |
rleishman
Messages: 3728
Registered: October 2005
Location: Melbourne, Australia
|
Senior Member |
|
|
If you don't like the way CBO chooses the driving table, you can use /*+LEADING(..)*/ or /*+ORDERED*/ hints to influence the join order.
Generally speaking the driving table should be the one with the most restrictive filtering WHERE clauses. If there are NO filetering predicates - or only non-restrictive predicates - then arrange the sort order that places the largest tables last.
Ross Leishman
|
|
|
|
| Selection of driving table [message #307202 is a reply to message #307173] |
Tue, 18 March 2008 02:25 |
vkrn
Messages: 18
Registered: March 2008
|
Junior Member |
|
|
Thanks .
If i want to use indexes for fine tuning of the queries,i should know whether indexes are available for my tables or not.
For that how can i get the index statistics for my table.
Thanks,
Kiran.
|
|
|
|
|
|
|
|
|
|
| Re: Selection of driving table [message #307873 is a reply to message #307202] |
Thu, 20 March 2008 04:03 |
msmallya
Messages: 66
Registered: March 2008
Location: AHMEDABAD, GUJARAT
|
Member |
|
|
If you are looking at how to find Indexes on a table, you can use this
select index_name, column_position, column_name, table_name from user_ind_columns
where table_name like upper('&FL%')
order by index_name, column_position;
where FL is your table_name
|
|
|
|
|
|
] 
Blog
Search
Help
Members
Register
Login
Home
.I am tuning the queries with respect to CBO(Cost Based Optimiztion).How to choose a particular table as driving table? Even in CBO also do the selection of driving table effect the performance?can anyone give me claer idea .......
