Re: Set explain utility

David Williams wrote: SNIP > Set explain output is ONLY created when you actually open the cursor, > I tested this on my machine at work today (4GL 6.0x / SE 7.1x).> > You get syntax errors if you try to prepare something which is > not valid syntax (I've had these yesterday!). > > Doing > > DATABASE djw > > MAIN > DEFINE x CHAR(200) > SET EXPLAIN ON > LET x = "select * from site" > PREPARE p1 FROM x > DECLARE c1 CURSOR FOR p1 > END MAIN> > no sqexplain.out produced. > I did exactly the same, on Version 4.1, 5.00, 6.0 and 7.22UC1 (OnLine) on different platforms like SCO Solaris HP-UX SINIX The sqexplain.out file exists immediately after the prepare. Please, try it again. > The optimizer DEFINATELY parses statements when they are prepared. > > The optimizer ONLY produces sqexplain.out files when the cursor if > opened. > > My next question is when is it optimizer, I assume when the cursor is > opened since otherwise a needed index could be dropped between when > the prepare is done and when the open is done... > > Anyone able to give a definate statement about when optimization is > done? > > > > -- > David Williams Bye Stefan