1 files changed, 20 insertions, 25 deletions
diff --git a/sqlglot/dialects/postgres.py b/sqlglot/dialects/postgres.py
index 0d74b3a..6418032 100644
--- a/sqlglot/dialects/postgres.py
+++ b/sqlglot/dialects/postgres.py
@@ -148,6 +148,22 @@ def _serial_to_generated(expression):
     return expression
 
 
+def _generate_series(args):
+    # The goal is to convert step values like '1 day' or INTERVAL '1 day' into INTERVAL '1' day
+    step = seq_get(args, 2)
+
+    if step is None:
+        # Postgres allows calls with just two arguments -- the "step" argument defaults to 1
+        return exp.GenerateSeries.from_arg_list(args)
+
+    if step.is_string:
+        args[2] = exp.to_interval(step.this)
+    elif isinstance(step, exp.Interval) and not step.args.get("unit"):
+        args[2] = exp.to_interval(step.this.this)
+
+    return exp.GenerateSeries.from_arg_list(args)
+
+
 def _to_timestamp(args):
     # TO_TIMESTAMP accepts either a single double argument or (text, text)
     if len(args) == 1:
@@ -195,29 +211,6 @@ class Postgres(Dialect):
         HEX_STRINGS = [("x'", "'"), ("X'", "'")]
         BYTE_STRINGS = [("e'", "'"), ("E'", "'")]
 
-        CREATABLES = (
-            "AGGREGATE",
-            "CAST",
-            "CONVERSION",
-            "COLLATION",
-            "DEFAULT CONVERSION",
-            "CONSTRAINT",
-            "DOMAIN",
-            "EXTENSION",
-            "FOREIGN",
-            "FUNCTION",
-            "OPERATOR",
-            "POLICY",
-            "ROLE",
-            "RULE",
-            "SEQUENCE",
-            "TEXT",
-            "TRIGGER",
-            "TYPE",
-            "UNLOGGED",
-            "USER",
-        )
-
         KEYWORDS = {
             **tokens.Tokenizer.KEYWORDS,
             "~~": TokenType.LIKE,
@@ -243,8 +236,6 @@ class Postgres(Dialect):
             "TEMP": TokenType.TEMPORARY,
             "UUID": TokenType.UUID,
             "CSTRING": TokenType.PSEUDO_TYPE,
-            **{f"CREATE {kind}": TokenType.COMMAND for kind in CREATABLES},
-            **{f"DROP {kind}": TokenType.COMMAND for kind in CREATABLES},
         }
         QUOTES = ["'", "$$"]
         SINGLE_TOKENS = {
@@ -257,8 +248,10 @@ class Postgres(Dialect):
 
         FUNCTIONS = {
             **parser.Parser.FUNCTIONS,  # type: ignore
+            "NOW": exp.CurrentTimestamp.from_arg_list,
             "TO_TIMESTAMP": _to_timestamp,
             "TO_CHAR": format_time_lambda(exp.TimeToStr, "postgres"),
+            "GENERATE_SERIES": _generate_series,
         }
 
         BITWISE = {
@@ -272,6 +265,8 @@ class Postgres(Dialect):
         }
 
     class Generator(generator.Generator):
+        LOCKING_READS_SUPPORTED = True
+
         TYPE_MAPPING = {
             **generator.Generator.TYPE_MAPPING,  # type: ignore
             exp.DataType.Type.TINYINT: "SMALLINT",