Getting plans for statements inside a function or procedure

[VolkerBarth]

I have been profiling a number of functions and procedures and this has highlighted a big difference (in the wrong direction, unfortunately) in performance of some individual statements within a number of functions after moving from v10.0.1 to 12.0.1.

Some of these statements are not straight selects or updates, but are in the form of a Watcom IF connstruct eg:

if VacID is not null and(exists(select 1 from Progress where Progress.VacancyID = VacID and Progress.PersonID = persid and Progress.status = '.')
or exists(select 1 from Progress where Progress.VacancyID = VacID and Progress.PersonID = persid and Progress.noreemploy = 1)) then
return 'V' end if;

This is just one of half a dozen similarly constructed statements in the function.

The application profiling / tracing viewer treats everything between the initial BEGIN and the final END as a single statement, so no plan is available. Obviously I could rewrite the statement as something like

select if VacID is not null and(exists(select 1 from Progress where Progress.VacancyID = VacID and Progress.PersonID = persid and Progress.status = '.')
or exists(select 1 from Progress where Progress.VacancyID = VacID and Progress.PersonID = persid and Progress.noreemploy = 1)) then 1 else 0 endif

then run that from isql and get a plan, but the query isn't quite the same and the context is quite different.

Is there some way of getting the plans for such statements as the are actually executed, in the context of the function / procedure?

---

UPDATE

Screen shot showing how the whole procedure is treated as a single statement, with no plan tab

[VolkerBarth]

...Is DESPERATION_LEVEL another coming knob? If so, what's the default, and can I set it on a per-user base?

[justin_willey]

Yup that's the one - I'll just have to wait until 2014 - probably about the time one of the queries is going to finish!

[Breck_Carter]

Are you sure Database Tracing doesn't capture queries executed inside stored procedures?

[justin_willey]

Part of the problem is that I don't really know how the IF statement is actually executed by the engine, ie is it recast as a SELECT, if so how etc? GRAPHICAL_PLAN() only takes SELECT, UPDATE and DELETE.

I presume the thing to do would be to fetch the plan for the statement, in re-written form, BEFORE doing it for real, so that the plan isn't changed by running the actual statement?

I rather like the LOG_EXPENSIVE_QUERY () idea - especially the way you would be able to have it in place at danger points and only invoke it when DESPERATION_LEVEL > (TOLERANCE_THRESHOLD - CAFFINE_QUOTIENT)

[justin_willey]

When I look at the detailed results you see the whole contents ie from BEGIN to END in the query column. Then when you click on that you see the contents in the query window with the overall timing but unlike a single statement there's no tab for the plan. I also looked to see if the individual statements are separately logged as well, but even after removing the filters I can't see them.

That doesn't mean I'm not missing something though!

---

I'll post some screen shots when I get a moment

[Breck_Carter]

@All: The "Comment Text Removed" isn't the work of some nefarious censor, it's the result of me deleting my own comments without realizing replies had already been posted. Oh, well... whatever you imagine the missing comments to be is probably more interesting than the (now forgotten) reality 🙂

[Breck_Carter]

FWIW... I usually start with the stored procedure profiler to find which statements are actually slow, before digging deeper. Sometimes, it is all I use, if the flaw is obvious once the statement is highlighted... and it's a LOT easier to use than database tracing.

[justin_willey]

Indeed, if only the tracing was as easy to use as the procedure profiling - turn on, look at results! That's how I got started down this route, then found I had to try to dig out the individual statements to why it had changed so much.

[Former Member]

I really don't understand, why only SA still don't has convenient mechanism for getting plans of any sql statements, without voodoo. Using Tracing/LogExpensiveQueries is not that thing that all wants today. For some statement 1min is very fast, for another -1ms - very slow. So how to use LogExpensiveQueries in that case? Please, just give us simple mechanism getting any plans without voodoo, like any other RDBMS has.

[Breck_Carter]

"A simple mechanism for getting plans without voodoo" is a good description of a much needed improvement... too bad it lacks management appeal.

Let's see... paradigm shift... adaptive server... unwired enterprise...

...got it! cloud computing!

How about "A simple mechanism for getting plans to improve cloud performance"?

[VolkerBarth]

...what's the current value of the brandnew BUZZWORD_LEVEL option...?

[justin_willey]

I'm sure it's essential for implementing IP6 🙂 or even better BIG DATA - the last one is even has the advantage of being true

[VolkerBarth]

And now is the time to give the slight pointer that in German (or my particular region), "Fuji" sounds similar to the colloquial "futsch" or its "italized" version "fut­schi­ka­to" - both meaning

lost, gone, broken

Some may claim that's a very fitting association with a cloud-based database, others may not...