I want to evaluate the performances of different query plans.

I dont really need TuneTable since I don't really care the statistics is correct or not.

I just have to evaluate impact of those different parameters feed into optimizer.

Below is my sample test program and it should reveal my intention.  It seems like BlockCount is not fetching the newest value from ^Blk when I compile. Any solution for this ?

<SQLMap name="Index">
<BlockCount> ^Blk</BlockCount>
</SQLMap>

 

set Blks = $lb(-100,-200,-300)

for = 1:1:$ll(Blks){
set ^Blk = $li(Blks,r)

do $system.SQL.Purge()
!,$system.OBJ.Compile("User.Table")
set query = "select XXXX"
set stat = ##class(%SQL.Statement).%New()
if 'stat.%Prepare(query) !,"prepare failed "_query
set startT = $zts
set = stat.%Execute()
set endT = $zts

//record startT and endT

}