Fix(optimizer): solve an infinite loop problem in simplify (#2071)

tobymao · Aug 16, 2023 · 3c493e9 · 3c493e9
1 parent 3c01cbf
commit 3c493e9
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Showing 2 changed files with 6 additions and 2 deletions.
diff --git a/sqlglot/optimizer/simplify.py b/sqlglot/optimizer/simplify.py
@@ -350,7 +350,8 @@ def absorb_and_eliminate(expression, root=True):
 def simplify_literals(expression, root=True):
     if isinstance(expression, exp.Binary) and not isinstance(expression, exp.Connector):
         return _flat_simplify(expression, _simplify_binary, root)
-    elif isinstance(expression, exp.Neg):
+
+    if isinstance(expression, exp.Neg):
         this = expression.this
         if this.is_number:
             value = this.name
@@ -645,7 +646,7 @@ def _flat_simplify(expression, simplifier, root=True):
             for b in queue:
                 result = simplifier(expression, a, b)
 
-                if result:
+                if result and result is not expression:
                     queue.remove(b)
                     queue.appendleft(result)
                     break

diff --git a/tests/fixtures/optimizer/simplify.sql b/tests/fixtures/optimizer/simplify.sql
@@ -615,6 +615,9 @@ TRUE;
 x = 2018 OR x <> 2018;
 x <> 2018 OR x = 2018;
 
+t0.x = t1.x AND t0.y < t1.y AND t0.y <= t1.y;
+t0.x = t1.x AND t0.y < t1.y AND t0.y <= t1.y;
+
 --------------------------------------
 -- Coalesce
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