Hi All,
Can someone please explain what this explain plan statement means? I see a filter(NULL IS NOT NULL) as the first statement - could not figure out why it came up so from googling.
My Query Used:
EXPLAIN PLAN FOR
MERGE INTO summary_bysrccd
USING
(SELECT LAST_DAY(TRUNC(to_timestamp(os.requestdatetime, 'yyyymmddhh24:mi:ss.ff4'))) AS SUMMARY_DATE,
os.acctnum,
ol.sourcecode AS sourcecode,
ol.sourcename AS sourcename,
count(1) cnt_articleview
FROM article_views os , master_sourcecode ol
where os.sourcecode = ol.sourcecode
AND os.acctnum IS NOT NULL
AND ol.sourcecode IS NOT NULL
AND os.requestdatetime IS NOT NULL
AND UPPER(os.success_ind) = 'S'
AND (
('INCR' = 'FULL'
AND (get_date_timestamp(os.requestdatetime) BETWEEN TO_DATE('23-AUG-2011 00:00:00','DD-MON-YYYY HH24:MI:SS') AND TO_DATE('27-AUG-2011 23:59:59','DD-MON-YYYY HH24:MI:SS')
AND os.entry_CreatedDate BETWEEN TO_DATE('22-AUG-2011 00:00:00','DD-MON-YYYY HH24:MI:SS') AND TO_DATE('28-AUG-2011 00:00:00','DD-MON-YYYY HH24:MI:SS')
))
OR ('INCR' = 'FULL'
AND os.entry_createddate BETWEEN TO_DATE('23-AUG-2011 00:00:00','DD-MON-YYYY HH24:MI:SS') AND TO_DATE('27-AUG-2011 23:59:59','DD-MON-YYYY HH24:MI:SS') )
)
group by LAST_DAY(TRUNC(to_timestamp(os.requestdatetime, 'yyyymmddhh24:mi:ss.ff4'))),
os.acctnum,ol.sourcecode,ol.sourcename) mrg_query
ON (ods_av_summary_bysrccd.acctnum = mrg_query.acctnum AND
ods_av_summary_bysrccd.summary_date=mrg_query.summary_date AND
ods_av_summary_bysrccd.sourcecode=mrg_query.sourcecode)
WHEN NOT MATCHED THEN
INSERT (SUMMARY_date,ACCTNUM,SOURCECODE,SOURCENAME,CNT_ARTICLEVIEW,ENTRY_LASTUPDATEDDATE)
VALUES(mrg_query.summary_date,mrg_query.acctnum,mrg_query.sourcecode,mrg_query.sourcename,
mrg_query.cnt_articleview,sysdate)
WHEN MATCHED THEN
UPDATE SET ods_av_summary_bysrccd.cnt_articleview=
CASE WHEN NVL('INCR','INCR') = 'FULL' THEN mrg_query.cnt_articleview
ELSE ods_av_summary_bysrccd.cnt_articleview+mrg_query.cnt_articleview
END,
ods_av_summary_bysrccd.entry_lastupdateddate=sysdate;
My Explain Plan:
SQL> select * from table(dbms_xplan.display);
PLAN_TABLE_OUTPUT
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Plan hash value: 268591246
-----------------------------------------------------------------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes |TempSpc| Cost (%CPU)| Time | Pstart| Pstop |
-----------------------------------------------------------------------------------------------------------------------------------------------
| 0 | MERGE STATEMENT | | 1 | 456 | | 3 (0)| 00:00:01 | | |
| 1 | MERGE | ODS_AV_SUMMARY_BYSRCCD | | | | | | | |
| 2 | VIEW | | | | | | | | |
| 3 | NESTED LOOPS OUTER | | 1 | 417 | | 3 (0)| 00:00:01 | | |
| 4 | VIEW | | 1 | 360 | | 5 (100)| 00:00:01 | | |
| 5 | SORT GROUP BY | | 1 | 73 | 595M| | | | |
PLAN_TABLE_OUTPUT
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|* 6 | FILTER | | | | | | | | |
|* 7 | HASH JOIN | | 6975K| 485M| 3944K| 17594 (1)| 00:03:32 | | |
| 8 | TABLE ACCESS FULL | ODS_MASTER_SOURCECODE | 84021 | 2953K| | 273 (1)| 00:00:04 | | |
|* 9 | TABLE ACCESS BY GLOBAL INDEX ROWID| ODS_ARTICLE_VIEWS | 7007K| 247M| | 826 (0)| 00:00:10 | 33 | 33 |
|* 10 | INDEX FULL SCAN | IDX_AV_ACCTNUM | 25M| | | 26 (0)| 00:00:01 | | |
| 11 | TABLE ACCESS BY GLOBAL INDEX ROWID | ODS_AV_SUMMARY_BYSRCCD | 1 | 57 | | 3 (0)| 00:00:01 | ROWID | ROWID |
|* 12 | INDEX UNIQUE SCAN | ODS_AV_SUMMARY_BYSRCCD_PK | 1 | | | 2 (0)| 00:00:01 | | |
-----------------------------------------------------------------------------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
PLAN_TABLE_OUTPUT
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
6 - filter(NULL IS NOT NULL)
7 - access("OS"."SOURCECODE"="OL"."SOURCECODE")
9 - filter("OS"."REQUESTDATETIME" IS NOT NULL AND "OS"."ENTRY_CREATEDDATE">=TO_DATE(' 2011-08-23 00:00:00', 'syyyy-mm-dd
hh24:mi:ss') AND "OS"."ENTRY_CREATEDDATE"<=TO_DATE(' 2011-08-27 23:59:59', 'syyyy-mm-dd hh24:mi:ss') AND UPPER("OS"."SUCCESS_IND")='S')
10 - filter("OS"."ACCTNUM" IS NOT NULL)
12 - access("ODS_AV_SUMMARY_BYSRCCD"."SUMMARY_DATE"(+)=INTERNAL_FUNCTION("MRG_QUERY"."SUMMARY_DATE") AND
"ODS_AV_SUMMARY_BYSRCCD"."ACCTNUM"(+)="MRG_QUERY"."ACCTNUM" AND "ODS_AV_SUMMARY_BYSRCCD"."SOURCECODE"(+)="MRG_QUERY"."SOURCECODE")
Note
-----
PLAN_TABLE_OUTPUT
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
- dynamic sampling used for this statement