Help to rewirte query for best performance

Question

Hi All,
can you kindly help me to rewirte the below mentioned query for best performance. this is taking more than 20 min in our production server.
SELECT cp.name,mis.secondary_type U_NAME,
count(CASE WHEN (mis.start_time between To_DATE(to_char(next_day (sysdate-161,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy') and To_DATE(to_char(next_day (sysdate-154,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy'))THEN mis.event_audit_id END) Usage,
count(CASE WHEN (mis.start_time between To_DATE(to_char(next_day (sysdate-154,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy') and To_DATE(to_char(next_day (sysdate-147,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy'))THEN mis.event_audit_id END) Usage,
count(CASE WHEN (mis.start_time between To_DATE(to_char(next_day (sysdate-147,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy') and To_DATE(to_char(next_day (sysdate-140,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy'))THEN mis.event_audit_id END) Usage,
count(CASE WHEN (mis.start_time between To_DATE(to_char(next_day (sysdate-140,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy') and To_DATE(to_char(next_day (sysdate-133,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy'))THEN mis.event_audit_id END) Usage,
count(CASE WHEN (mis.start_time between To_DATE(to_char(next_day (sysdate-133,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy') and To_DATE(to_char(next_day (sysdate-126,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy'))THEN mis.event_audit_id END) Usage,
count(CASE WHEN (mis.start_time between To_DATE(to_char(next_day (sysdate-126,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy') and To_DATE(to_char(next_day (sysdate-119,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy'))THEN mis.event_audit_id END) Usage,
count(CASE WHEN (mis.start_time between To_DATE(to_char(next_day (sysdate-119,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy') and To_DATE(to_char(next_day (sysdate-112,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy'))THEN mis.event_audit_id END) Usage,
count(CASE WHEN (mis.start_time between To_DATE(to_char(next_day (sysdate-112,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy') and To_DATE(to_char(next_day (sysdate-105,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy'))THEN mis.event_audit_id END) Usage,
count(CASE WHEN (mis.start_time between To_DATE(to_char(next_day (sysdate-105,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy') and To_DATE(to_char(next_day (sysdate-98,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy'))THEN mis.event_audit_id END) Usage,
count(CASE WHEN (mis.start_time between To_DATE(to_char(next_day (sysdate-98,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy') and To_DATE(to_char(next_day (sysdate-91,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy'))THEN mis.event_audit_id END) Usage,
count(CASE WHEN (mis.start_time between To_DATE(to_char(next_day (sysdate-91,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy') and To_DATE(to_char(next_day (sysdate-84,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy'))THEN mis.event_audit_id END) Usage,
count(CASE WHEN (mis.start_time between To_DATE(to_char(next_day (sysdate-84,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy') and To_DATE(to_char(next_day (sysdate-77,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy'))THEN mis.event_audit_id END) Usage,
count(CASE WHEN (mis.start_time between To_DATE(to_char(next_day (sysdate-77,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy') and To_DATE(to_char(next_day (sysdate-70,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy'))THEN mis.event_audit_id END) Usage,
count(CASE WHEN (mis.start_time between To_DATE(to_char(next_day (sysdate-70,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy') and To_DATE(to_char(next_day (sysdate-63,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy'))THEN mis.event_audit_id END) Usage,
count(CASE WHEN (mis.start_time between To_DATE(to_char(next_day (sysdate-63,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy') and To_DATE(to_char(next_day (sysdate-56,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy'))THEN mis.event_audit_id END) Usage,
count(CASE WHEN (mis.start_time between To_DATE(to_char(next_day (sysdate-56,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy') and To_DATE(to_char(next_day (sysdate-49,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy'))THEN mis.event_audit_id END) Usage,
count(CASE WHEN (mis.start_time between To_DATE(to_char(next_day (sysdate-49,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy') and To_DATE(to_char(next_day (sysdate-42,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy'))THEN mis.event_audit_id END) Usage,
count(CASE WHEN (mis.start_time between To_DATE(to_char(next_day (sysdate-42,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy') and To_DATE(to_char(next_day (sysdate-35,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy'))THEN mis.event_audit_id END) Usage,
count(CASE WHEN (mis.start_time between To_DATE(to_char(next_day (sysdate-35,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy') and To_DATE(to_char(next_day (sysdate-28,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy'))THEN mis.event_audit_id END) Usage,
count(CASE WHEN (mis.start_time between To_DATE(to_char(next_day (sysdate-28,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy') and To_DATE(to_char(next_day (sysdate-21,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy'))THEN mis.event_audit_id END) Usage,
count(CASE WHEN (mis.start_time between To_DATE(to_char(next_day (sysdate-21,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy') and To_DATE(to_char(next_day (sysdate-14,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy'))THEN mis.event_audit_id END) Usage,
count(CASE WHEN (mis.start_time between To_DATE(to_char(next_day (sysdate-14,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy') and To_DATE(to_char(next_day (sysdate-7,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy'))THEN mis.event_audit_id END) Usage
FROM mis_event_audit mis,USER u,com_pros cp where
mis.user_id=u.email_address and u.cp_id=cp.cp_id
and (mis.start_time between To_DATE(to_char(next_day (sysdate-161,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy') and To_DATE(to_char(next_day (sysdate-7,'monday'),'MM/DD/YYYY'),'mm/dd/yyyy'))
GROUP BY cp.name, mis.secondary_type;
Thanks,
krish

Answer 1

Hi, Krish,
Something like this will probably be faster, because it cuts out most of the function calls:
WITH     got_cnt          AS
     SELECT    cp.name
     ,       mis.secondary_type          AS u_name
     ,       COUNT (mis.event_audit_id)     AS cnt
     ,       ( TRUNC (mis.start_time, 'IW')
            - TRUNC (SYSDATE,        'IW')
            ) / 7                    AS week_num
     FROM      mis_event_audit  mis
     JOIN       user_table        u     ON   mis.user_id  = u.email_address     -- USER is not a good table name
     JOIN       com_pros        cp     ON   u.cp_id       = cp.cp_id
     WHERE       mis.start_time   >= TRUNC (SYSDATE, 'IW') - 161
     AND       mis.start_time   <  TRUNC (SYSDATE, 'IW')
     GROUP BY  cp.name
     ,            mis.secondary_type
     ,       TRUNC (mis.start_time, 'IW')
SELECT       name
,       secondary_type
,       SUM (CASE WHEN week_num = 22 THEN cnt END)     AS week_23
,       SUM (CASE WHEN week_num = 21 THEN cnt END)     AS week_22
,       SUM (CASE WHEN week_num = 20 THEN cnt END)     AS week_21
,       SUM (CASE WHEN week_num =  0  THEN cnt END)     AS week_1
FROM       got_cnt
GROUP BY  name
,            secondary_type
;TRUNC (d, 'IW')       is midnight on the last Monday before or equal to the DATE d. It does not depend on you NLS settings.
Whenever you're tempted to write an exprssion as complicated as
,     COUNT ( CASE
                   WHEN ( mis.start_time BETWEEN TO_DATE ( TO_CHAR ( NEXT_DAY  ( SYSDATE - 161
                                                                   , 'monday'
                                              , 'MM/DD/YYYY'
                                    , 'MM/DD/YYYY'
                          AND     TO_DATE ( TO_CHAR ( NEXT_DAY ( SYSDATE - 154
                                                             ,'monday'
                                            , 'MM/DD/YYYY'
                                      , 'MM/DD/YYYY'
              THEN mis.event_audit_id
           END
         )               AS usageseek alternate ways. Oracle provides several handy functions, especially for manipulating DATEs. In particular "TO_DATE (TO_CHAR ...)" is almost never needed; think very carefully before doing a round-trip conversion like that.
Besides being more efficient, this will be easier to debug and maintain.
If you're using Oracle 11.1 (or higher), then you can also use SELECT ... PIVOT in the main query, but I doubt that will be any faster, and it might not be any simpler.
I hope this answers your question.
If not, post a little sample data (CREATE TABLE and INSERT statements, relevant columns only) for all tables involved, and also post the results you want from that data.
Explain, using specific examples, how you get those results from that data.
Simplify the problem as much as possible. For example, instead of posting a problem that covers the last 23 weeks, pretend that you're only interested in the last 3 weeks. You'll get a solution that's easy to adapt to any number of weeks.
Always say which version of Oracle you're using (e.g., 11.2.0.2.0).
See the forum FAQ {message:id=9360002}
For performance problems, there's another page of the forum FAQ {message:id=9360003}, but, before you start that process, let's get a cleaner query, without so many functions.
Edited by: Frank Kulash on Oct 2, 2012 11:50 AM
Changed week_num to be non-negative