In continuation of my discussion regarding Plan and DSN_STATEMNT table, I am now giving you the code thru which you can EXPLAIN your SQL statements and find the parameters populated in both of the tables mentioned above. This will help you in your analysis of performance regarding SQL you are going to run.
1) You should have all the objects (Referenced in your SQL) created in the same env where you will Explain the SQL.
2) You tables must be runstated before running Explain
3) You can replace host variables with any Char/Int Literals in the SQL statements.
4) Make sure your PLAN_TABLE and DSN_STATEMNT_TABLE present in the same Env.
Here is one example of SQL code regarding How to Explain your query.
DELETE FROM PLAN_TABLE WHERE QUERYNO = 99999;
EXPLAIN PLAN SET QUERYNO = 99999 FOR
SELECT B.STORE_NO, B.STOCK_ITEM, B.DELIVERY_DATE
FROM V1FOGH01 B
WHERE DELIVERY_DATE = (SELECT MAX(DELIVERY_DATE)
FROM V1FOGH01 A
WHERE A.STORE_NO = B.STORE_NO
AND A.STOCK_ITEM = B.STOCK_ITEM
AND A.QTY_TYPE ='7'
AND A.DELIVERY_DATE <= CURRENT DATE)
AND B.QTY_TYPE ='7';
SELECT * FROM PLAN_TABLE
WHERE QUERYNO = 99999
ORDER BY TIMESTAMP,QUERYNO,QBLOCKNO,PLANNO,MIXOPSEQ;
SELECT * FROM DSN_STATEMNT_TABLE
WHERE QUERYNO = 99999;
I have Added the Select statement so that immediately you can view the result. You can run this statement in Batch as well as Online (Spufi).
I have already discussed some important columns of PLAN_TABLE and DSN_STATEMNT_TABLE. So Enjoy while analysing the values you got for these 2 tables.
Prakash C Singh
IBM Certified DB2 DBA.