Need help in tuning a sql-query
- by Viper
Hello,
i need some help to boost this SQL-Statement. The execution time is around 125ms.
During the runtime of my program this sql (better: equally structured sqls for different tables)
will be called 300.000 times.
The average row count in the tables lies around 10.000.000 rows and new rows (updates/inserts) will be added with a timestamp each day. Data which are interesting for this particular export-program lies in the last 1-3 days. Maybe this is helpful for an index to create. The data i need is the current valid row for a given id and the forerunner datarow to get the updates (if exists).
We use a Oracle 11g database and Dot.Net Framework 3.5
SQL-Statement to boost:
select
ID_SOMETHING, -- Number(12)
ID_CONTRIBUTOR, -- Char(4 Byte)
DATE_VALID_FROM, -- DATE
DATE_VALID_TO -- DATE
from
TBL_SOMETHING XID
where
ID_SOMETHING = :ID_INSTRUMENT
and ID_CONTRIBUTOR = :ID_CONTRIBUTOR
and DATE_VALID_FROM <= :EXPORT_DATE
and DATE_VALID_TO >= :EXPORT_DATE
order by
DATE_VALID_FROM asc;
Here i uploaded the current Explain-Plan for this query.
I'm not a database expert so i don't know which index-type would fit best for this requirement.
I have seen that there are many different possible index-types which could be applied.
Maybe Oracle Optimizer Hints are helpful, too.
Does anyone has a good idea for tuning this sql or can point me in a right direction?