what is the steps followed in EXPLAIN Process or EXPLAIN
command. (Explain is for identifying the optimized access
path but how or what is the steps for doing the EXPLAIN)
- 4 Answers
- 7137 Views
- IBM, I also Faced
- E-Mail Answers
Answers were Sorted based on User's Feedback
Answer / bob
Small Correction: With explain(Yes) option, Access path or optimizer's strategy/information will be stored in package_owner.plan_table
| Is This Answer Correct ? | 6 Yes | 0 No |
Answer / sachin borase
Optimized access path means:
When we are runnign any query database make the
path to db2 for fetching the required data called as
optimized acess path.for creating optimized access path
db2 uses db2 catlg.
expalain?
if put EXPLAIN(yes) then optimized path will sotred
whatever query you written in the program in the
table owner.plan_table
How to acess:
if you acess the owner.plan_table
it will have the below imp coloumns.
1.program name
2.latest timestamp
3.indexused
4.and more details
| Is This Answer Correct ? | 2 Yes | 0 No |
Answer / sdexcellent@yahoo.co.in
EXPLAIN is used to display the access path as determined by
the optimizer for a SQL statement.
It can be used in SPUFI (for single SQL statement ) or in
BIND step (for embedded SQL ).
plan table should be created under your authid.if its there
then only EXPLAIN can be used in SPUFI.
Output of EXPLAIN can be stored in userid.plantable
in spufi u ve to write the query with ?
select billtn,lpic from xxxx where lpic > ?
| Is This Answer Correct ? | 1 Yes | 0 No |
Answer / krishna
In bind parameter if you give like
EXPLAIN(YES)
This will store the acess path in SYSIBM.SYSPLAN table,
it will not do any optimization.
| Is This Answer Correct ? | 1 Yes | 1 No |
AGGREGATE function support by DB2. A) SUM & AVG B) SUM, MIN & AVG C) SUM, MAX, AVG , MIN &COUNT D) NONE
When would you prefer to use VARCHAR?
Is it mandatory to use DCLGEN? If not, why would you use it at all?
Can we use group-by clause in sub-query? If 'yes' means,Will it be executed successfully or else If 'no' means why should we not using that method? Give me your suggestion please....
Is it possible to update a primary key value? If not, what is the error code given? If yes, can more than 1 primary key column be updated at a time?
can any body explain about plan and pakage in detail....
What is a DB2 access path?
Return code 100 means?
What does the sqlcode of -818 pertain to?
What is the maximum No of rows per page?
What is QUIESCE?
How can tablespace be moved to another dasd volume that is allocated for that tablespace?
COBOL 
