I've come across something peculiar re RushMore.

Basically, it's as if it were not seeing some index entries

I've nailed it down to a simple test, but in real life, a select would return eg 64 records where it should return eg 108

The only way around I've found so far is to not use the index expression, use (j_ref = 0) instead of (bintoc(j_ref) == bintoc(0))

Disabling Rushmore gives correct results in both locate and scan, but not in select sql

I'd like to (1) understand what is going on and (2) find a way around it and use the index expr

function Do_It()
	
	
	set ansi on
	set exact on
	set collate to 'machine'
	set optimize on
	
	create cursor CursorTest ;
		( 	j_ref		I ;
		)
	
	insert into CursorTest values(44 )
	insert into CursorTest values( 0 )
	insert into CursorTest values(44 )

	index on bintoc(j_ref) tag j_ref

	?'-------------------------------------'
	
	locate for (bintoc(j_ref) == bintoc(0))
	?'optimize locate 0 (TRUE)', found(), '  ERROR'

	locate for (bintoc(j_ref) == bintoc(0)) NOOPTIMIZE
	?'no optimize locate 0 (TRUE)', found(), ' OK'
	
	local aa[1]
	aa[1] = 0
	
	select count(*) ;
		from CursorTest ;
		into array aa ;
		where (bintoc(j_ref) == bintoc(0))
	
	?'optimize count 0 (1):', aa[1], ' ERROR'
	
	set optimize off
	select count(*) ;
		from CursorTest ;
		into array aa ;
		where (bintoc(j_ref) == bintoc(0))
	set optimize on
	
	?'no optimize count 0 (1):', aa[1], aa[1], ' ERROR'
	
	
	locate for (bintoc(j_ref) == bintoc(44))
	?'optimize locate 44 (TRUE), recno 1:', found(), 'OK ', recno()
	
	insert into CursorTest  values( 0 )
	locate for (bintoc(j_ref) == bintoc(0))
	?'optimize locate 0 (TRUE), recno 2:', found(), recno(), 'ERROR'
	

endfunc