1 files changed, 0 insertions, 88 deletions
diff --git a/sqlglot/optimizer/lower_identities.py b/sqlglot/optimizer/lower_identities.py
deleted file mode 100644
index fae1726..0000000
--- a/sqlglot/optimizer/lower_identities.py
+++ /dev/null
@@ -1,88 +0,0 @@
-from sqlglot import exp
-
-
-def lower_identities(expression):
-    """
-    Convert all unquoted identifiers to lower case.
-
-    Assuming the schema is all lower case, this essentially makes identifiers case-insensitive.
-
-    Example:
-        >>> import sqlglot
-        >>> expression = sqlglot.parse_one('SELECT Bar.A AS A FROM "Foo".Bar')
-        >>> lower_identities(expression).sql()
-        'SELECT bar.a AS A FROM "Foo".bar'
-
-    Args:
-        expression (sqlglot.Expression): expression to quote
-    Returns:
-        sqlglot.Expression: quoted expression
-    """
-    # We need to leave the output aliases unchanged, so the selects need special handling
-    _lower_selects(expression)
-
-    # These clauses can reference output aliases and also need special handling
-    _lower_order(expression)
-    _lower_having(expression)
-
-    # We've already handled these args, so don't traverse into them
-    traversed = {"expressions", "order", "having"}
-
-    if isinstance(expression, exp.Subquery):
-        # Root subquery, e.g. (SELECT A AS A FROM X) LIMIT 1
-        lower_identities(expression.this)
-        traversed |= {"this"}
-
-    if isinstance(expression, exp.Union):
-        # Union, e.g. SELECT A AS A FROM X UNION SELECT A AS A FROM X
-        lower_identities(expression.left)
-        lower_identities(expression.right)
-        traversed |= {"this", "expression"}
-
-    for k, v in expression.iter_expressions():
-        if k in traversed:
-            continue
-        v.transform(_lower, copy=False)
-
-    return expression
-
-
-def _lower_selects(expression):
-    for e in expression.expressions:
-        # Leave output aliases as-is
-        e.unalias().transform(_lower, copy=False)
-
-
-def _lower_order(expression):
-    order = expression.args.get("order")
-
-    if not order:
-        return
-
-    output_aliases = {e.alias for e in expression.expressions if isinstance(e, exp.Alias)}
-
-    for ordered in order.expressions:
-        # Don't lower references to output aliases
-        if not (
-            isinstance(ordered.this, exp.Column)
-            and not ordered.this.table
-            and ordered.this.name in output_aliases
-        ):
-            ordered.transform(_lower, copy=False)
-
-
-def _lower_having(expression):
-    having = expression.args.get("having")
-
-    if not having:
-        return
-
-    # Don't lower references to output aliases
-    for agg in having.find_all(exp.AggFunc):
-        agg.transform(_lower, copy=False)
-
-
-def _lower(node):
-    if isinstance(node, exp.Identifier) and not node.quoted:
-        node.set("this", node.this.lower())
-    return node