postgres.git / summary / log / commit / refs

commit    ff68b256a533b398e3420750f34d161aeee4e099
Author:   Tom Lane <tgl@sss.pgh.pa.us>
Date:     Mon Dec 05 20:50:06 2011 +0000

    Remove troublesome Asserts in cost_mergejoin().
    
    While logically correct, these two Asserts could fail depending on the
    vagaries of floating-point arithmetic.  In particular, on machines with
    floating-point registers wider than standard "double" values, it was
    possible for the compiler to compare a rounded-to-double value already
    stored in memory with an unrounded long double value still in a register.
    Given the preceding checks, these assertions aren't adding much, so let's
    just get rid of them rather than try to find a compiler-proof fix.
    Per report from Pavel Stehule.
    
    Given the lack of previous complaints, and the fact that only developers
    would be likely to trip over it, I'm only going to change this in HEAD,
    even though the code has been like this for a long time.


 src/backend/optimizer/path/costsize.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c
index 348c36b40e3..db663203dac 100644
--- a/src/backend/optimizer/path/costsize.c
+++ b/src/backend/optimizer/path/costsize.c
@@ -1933,9 +1933,6 @@ cost_mergejoin(MergePath *path, PlannerInfo *root, SpecialJoinInfo *sjinfo)
 	outerendsel = outer_rows / outer_path_rows;
 	innerendsel = inner_rows / inner_path_rows;
 
-	Assert(outerstartsel <= outerendsel);
-	Assert(innerstartsel <= innerendsel);
-
 	/* cost of source data */
 
 	if (outersortkeys)			/* do we need to sort outer? */


[parent: 89e850e6fda9]