SYS_CONTEXT usage taking time for first run

Question

Hi all,
we have a screen(search) with conditions like make, manufacturing date, region, etc upto 20 conditions. User can restrict the result he wants based on the filters specified. As there are more parameters, a static query was takign a lot of time to return the result.
We went with dynamic query(only adding the conditions that user has specified in the screen dynamically) and to avoid hard parsing we introduced sys_context.
we found the result amazing with the subsequent run taking very less time(3-10 secs max) to fetch the results. But the first run (which goes for hard parsing done) is taking a quite a lot of time (close to 10mins).
we are using Oracle 11g.
thought this query is used on a regular basis, sometimes the sqlID gets cleared off from the cache due to LRU algorithm. Also sometimes, I see there are more than one SQL ID getting generated for the same set of parameter.
we cannot use the sql pin option as we would need to pin the sql for every combination of parameter(around 30).
Could anyone suggest a way of reducing the first run time?
Thanks in advance..
Regards,
Ela

Answer 1

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we cannot use the sql pin option as we would need to pin the sql for every combination of parameter(around 30).
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Then try specifying 'something' for every condition and using '%' for the context values that you don't care about.
If you don't care about 'empno' use '%' for the context value.
select * from emp where empno like '%'If you do care use an actual value
select * from emp where empno like '7369'The 'like' will be treated as '=' for the second case and in the first case it should be optimized out in the actual query.
That way every query has the same 30 placeholders but the '%' will optimize out the ones you don't want to use.