Expert Oracle Exadata - Parent Directory

CHAPTER 4 STORAGE INDEXES-------------------------------------------------------------------------| Id|Operation |Name | Rows|Bytes|Cost (%CPU)|Time |-------------------------------------------------------------------------| 0|SELECT STATEMENT | | | | 535K(100)| || 1| SORT AGGREGATE | | 1| 8 | | ||* 2| TABLE ACCESS STORAGE FULL|SKEW3 | 384|3072 | 535K (2)|01:47:04|-------------------------------------------------------------------------Predicate Information (identified by operation id):---------------------------------------------------2 - storage("COL3"='20-OCT-05')filter("COL3"='20-OCT-05')20 rows selected.SYS@EXDB1> /Enter value for sql_id: 2s58n6d3mzkmnEnter value for child_no:PLAN_TABLE_OUTPUT--------------------------------------------------------------------------------------------SQL_ID 2s58n6d3mzkmn, child number 0-------------------------------------select count(*) from kso.skew3 where col3 = '20-OCT-2005'Plan hash value: 2684249835------------------------------------------------------------------------------------| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |------------------------------------------------------------------------------------| 0 | SELECT STATEMENT | | | | 531K(100)| || 1 | SORT AGGREGATE | | 1 | 8 | | ||* 2 | TABLE ACCESS STORAGE FULL| SKEW3 | 384 | 3072 | 531K (1)| 01:46:24 |------------------------------------------------------------------------------------Predicate Information (identified by operation id):---------------------------------------------------2 - storage("COL3"=TO_DATE(' 2005-10-20 00:00:00', 'syyyy-mm-ddhh24:mi:ss'))filter("COL3"=TO_DATE(' 2005-10-20 00:00:00', 'syyyy-mm-ddhh24:mi:ss'))22 rows selected.It appears that the optimizer didn’t recognize the two-digit date as a date. At the very least, theoptimizer failed to apply the to_date function to the literal and so the Storage Index was not used.Fortunately most of these types of data conversion issues have been resolved with the later releases.Here’s the same test using cellsrv 11.2.2.2.0:121