How to optimize this select statement its a simple select....

Question

how to optimize this select statement  as the records in earlier table is abt i million
and this simplet select statement is not executing and taking lot of time
  SELECT  guid  
                stcts      
  INTO table gt_corcts
  FROM   corcts
  FOR all entries in gt_mege
  WHERE  /sapsll/corcts~stcts = gt_mege-ctsex
  and /sapsll/corcts~guid_pobj = gt_Sagmeld-guid_pobj.
regards
Arora

Answer 1

Hi Arora,
Using Package size is very simple and you can avoid the time out and as well as the problem because of memory.  Some time if you have too many records in the internal table, then you will get a short dump called TSV_TNEW_PAGE_ALLOC_FAILED.
Below is the sample code.
DATA p_size = 50000
SELECT field1 field2 field3
   INTO TABLE itab1 PACKAGE SIZE p_size
   FROM dtab
   WHERE <condition>
Other logic or process on the internal table itab1
FREE itab1.
ENDSELECT.
Here the only problem is you have to put the ENDSELECT.
How it works
In the first select it will select 50000 records ( or the p_size you gave).  That will be in the internal table itab1.
In the second select it will clear the 50000 records already there and append next 50000 records from the database table.
So care should be taken to do all the logic or process with in select and endselect.
Some ABAP standards may not allow you to use select-endselect.  But this is the best way to handle huge data without short dumps and memory related problems. 
I am using this approach.  My data is much more huge than yours.  At an average of atleast 5 millions records per select.
Good luck and hope this help you.
Regards,
Kasthuri Rangan Srinivasan