From e0fd167849b8531afc99c7bb250b89f4251782c1 Mon Sep 17 00:00:00 2001
From: Harshal Sheth <hsheth2@gmail.com>
Date: Mon, 21 Oct 2024 23:20:23 -0700
Subject: [PATCH] move to new scope depth

---
 sqlglot/lineage.py         |  7 +------
 sqlglot/optimizer/scope.py | 15 +++++++--------
 2 files changed, 8 insertions(+), 14 deletions(-)

diff --git a/sqlglot/lineage.py b/sqlglot/lineage.py
index dc76a07d3d..2c9c1f5e10 100644
--- a/sqlglot/lineage.py
+++ b/sqlglot/lineage.py
@@ -294,12 +294,7 @@ def to_node(
             subfield = ".".join(subfields)
 
             node.downstream.append(
-                Node(
-                    name=c.sql(comments=False),
-                    source=source,
-                    expression=source,
-                    subfield=subfield,
-                )
+                Node(name=c.sql(comments=False), source=source, expression=source, subfield=subfield)
             )
 
     return node
diff --git a/sqlglot/optimizer/scope.py b/sqlglot/optimizer/scope.py
index 0a98d57b73..17009cdb86 100644
--- a/sqlglot/optimizer/scope.py
+++ b/sqlglot/optimizer/scope.py
@@ -14,8 +14,6 @@
 
 TRAVERSABLES = (exp.Query, exp.DDL, exp.DML)
 
-MAX_SCOPE_DEPTH = 500
-
 
 class ScopeType(Enum):
     ROOT = auto()
@@ -454,7 +452,6 @@ def remove_source(self, name):
 
     def __repr__(self):
         return f"Scope<{self.expression.sql()}>"
-
     def traverse(self):
         """
         Traverse the scope tree from this node.
@@ -463,9 +460,16 @@ def traverse(self):
             Scope: scope instances in depth-first-search post-order
         """
         stack = [self]
+        seen_scopes = set()
         result = []
         while stack:
             scope = stack.pop()
+
+            # Scopes aren't hashable, so we use id(scope) instead.
+            if id(scope) in seen_scopes:
+                raise OptimizeError(f"Scope {scope} has a circular scope dependency")
+            seen_scopes.add(id(scope))
+
             result.append(scope)
             stack.extend(
                 itertools.chain(
@@ -475,11 +479,6 @@ def traverse(self):
                     scope.subquery_scopes,
                 )
             )
-            actual_depth = len(result)
-            if actual_depth > MAX_SCOPE_DEPTH:
-                raise OptimizeError(
-                    f"Scope depth limit of {MAX_SCOPE_DEPTH} exceeded"
-                )
 
         yield from reversed(result)