SET EXPLAIN question

Posted in 1999

M Ramasubramanian — Thu, 21 Jan 1999 20:15:04 +0530 — source: Informix-list mailing list archive (1991-1998)

I have an application that links several .ec files, and I need to get the explain output in sqexplain.out using SET EXPLAIN ON. How should I place the SET EXPLAIN ON statements : once per file, once per function, once for the entire executable, etc. ? I would like to get the output for each query executed by the program. The manual for 7.2 does not seem to explain this. Thanks and regards, ramsub

↪ replying to M Ramasubramanian

Art S. Kagel — Thu, 21 Jan 1999 12:58:38 -0500 — source: Informix-list mailing list archive (1991-1998)

M Ramasubramanian wrote: > > I have an application that links several .ec files, and I need to get the > explain output in sqexplain.out using SET EXPLAIN ON. How should > I place the SET EXPLAIN ON statements : once per file, once per > function, once for the entire executable, etc. ? I would like to get the > output for each query executed by the program. The manual for 7.2 > does not seem to explain this. SET EXPLAIN... turns explain processing on or off from the point ofexecution to the end of the session or the next reversing SET EXPLAIN statement. So to trap all statements place the SET EXPLAIN ON after the DATABASE or CONNECT TO statement and before the execution of any queries. Place the SET EXPLAIN OFF before exiting the program or executing a DISCONNECT statement. Art S. Kagel

↪ replying to Art S. Kagel

Dino Gomez — Thu, 21 Jan 1999 14:50:42 -0500 — source: Informix-list mailing list archive (1991-1998)

Remember, the 'sqlexplain.out' file doesn't get flushed until the end of the session. -Dino Art S. Kagel wrote: > M Ramasubramanian wrote: > > > > I have an application that links several .ec files, and I need to get the > > explain output in sqexplain.out using SET EXPLAIN ON. How should > > I place the SET EXPLAIN ON statements : once per file, once per > > function, once for the entire executable, etc. ? I would like to get the > > output for each query executed by the program. The manual for 7.2 > > does not seem to explain this. > > SET EXPLAIN... turns explain processing on or off from the point of> execution to the end of the session or the next reversing SET EXPLAIN > statement. So to trap all statements place the SET EXPLAIN ON after > the DATABASE or CONNECT TO statement and before the execution of any > queries. Place the SET EXPLAIN OFF before exiting the program or > executing a DISCONNECT statement. > > Art S. Kagel

↪ replying to Dino Gomez

June Tong — Fri, 22 Jan 1999 21:24:19 -0800 — source: Informix-list mailing list archive (1991-1998)

Dino Gomez wrote: > Remember, the 'sqlexplain.out' file doesn't get flushed until the end of the > session. Um, if this means what it sounds to me like it means, then I don't think it's true. sqexplain.out is written to as soon as the optimizer finishes processing the query plan. I've never had a problem with this. June -- june_t@hotmail.com Grounded in Palo Alto, living on M&M's (plain)