Hi,
I've just been looking into the TPC-H benchmark with intention to put together some scripts which can be run easily to output some run times for each of the 22 queries.
I've not had a great deal of exposure to pgbench yet, but I had thought that it might be able to help me run these queries with the randomly chosen inputs that are described in the TPC-H spec.
1. DATE is the first of January of a randomly selected year within [1993 .. 1997];
2. DISCOUNT is randomly selected within [0.02 .. 0.09];
3. QUANTITY is randomly selected within [24 .. 25].
With pgbench I can do:
\setrandom qty 24 25
then throw a :qty into the query and have pgbench replace that with either 24 or 25.
The problem is that this does not work for anything apart from integer types.
I also can't seem to do anything with the date type. Perhaps it would be nice to be able to do something like:
\setrandom date '1993-01-01' '1994-01-01' '1995-01-01' '1996-01-01' '1997-01-01'
But this would be ambiguous if I wanted to choose either from either 10 or 20 as:
\setrandom var 10 20
would choose a random number between 10 and 20, not 10 or 20.
I would imagine that code could be added to allow the random to choose a floating point number, if one or more of the inputs had a decimal point in them, but I can't see around how to make it work with lists without changing the syntax.
Perhaps [between] could become a optional keyword in there so that we could do:
\setrandom var between 0 10
And for lists it could work like:
\setrandom var list 'a' 'b' 'c'
There should be no conflicts with the original syntax, as as far as I'm aware only an integer number can follow the variable name.
I was planning on putting something together to help me with this, but I thought I'd post here first so that I might actually end up with something useful at the end of it.
So my questions are:
1. Would anyone else find this useful?
2. Is my proposed syntax ok? Can you think of anything better or more flexible?
Regards
David Rowley
