diff --git a/sqlmesh/core/engine_adapter/postgres.py b/sqlmesh/core/engine_adapter/postgres.py
index 9962c037ac..a736f5553b 100644
--- a/sqlmesh/core/engine_adapter/postgres.py
+++ b/sqlmesh/core/engine_adapter/postgres.py
@@ -1,8 +1,9 @@
 from __future__ import annotations
 
 import logging
+import re
 import typing as t
-from functools import partial
+from functools import cached_property, partial
 from sqlglot import exp
 
 from sqlmesh.core.engine_adapter.base_postgres import BasePostgresEngineAdapter
@@ -112,11 +113,8 @@ def merge(
         **kwargs: t.Any,
     ) -> None:
         # Merge isn't supported until Postgres 15
-        merge_impl = (
-            super().merge
-            if self._connection_pool.get().server_version >= 150000
-            else partial(logical_merge, self)
-        )
+        major, minor = self.server_version
+        merge_impl = super().merge if major >= 15 else partial(logical_merge, self)
         merge_impl(  # type: ignore
             target_table,
             source_table,
@@ -125,3 +123,13 @@ def merge(
             when_matched=when_matched,
             merge_filter=merge_filter,
         )
+
+    @cached_property
+    def server_version(self) -> t.Tuple[int, int]:
+        """Lazily fetch and cache major and minor server version"""
+        if result := self.fetchone("SHOW server_version"):
+            server_version, *_ = result
+            match = re.search(r"(\d+)\.(\d+)", server_version)
+            if match:
+                return int(match.group(1)), int(match.group(2))
+        return 0, 0
diff --git a/sqlmesh/core/state_sync/db/snapshot.py b/sqlmesh/core/state_sync/db/snapshot.py
index 6064993087..30e0de00f2 100644
--- a/sqlmesh/core/state_sync/db/snapshot.py
+++ b/sqlmesh/core/state_sync/db/snapshot.py
@@ -372,25 +372,31 @@ def update_auto_restatements(
         Args:
             next_auto_restatement_ts: A dictionary of snapshot name version to the next auto restatement timestamp.
         """
+        next_auto_restatement_ts_deleted = []
+        next_auto_restatement_ts_filtered = {}
+        for k, v in next_auto_restatement_ts.items():
+            if v is None:
+                next_auto_restatement_ts_deleted.append(k)
+            else:
+                next_auto_restatement_ts_filtered[k] = v
+
         for where in snapshot_name_version_filter(
             self.engine_adapter,
-            next_auto_restatement_ts,
+            next_auto_restatement_ts_deleted,
             column_prefix="snapshot",
             alias=None,
             batch_size=self.SNAPSHOT_BATCH_SIZE,
         ):
             self.engine_adapter.delete_from(self.auto_restatements_table, where=where)
 
-        next_auto_restatement_ts_filtered = {
-            k: v for k, v in next_auto_restatement_ts.items() if v is not None
-        }
         if not next_auto_restatement_ts_filtered:
             return
 
-        self.engine_adapter.insert_append(
+        self.engine_adapter.merge(
             self.auto_restatements_table,
             _auto_restatements_to_df(next_auto_restatement_ts_filtered),
             columns_to_types=self._auto_restatement_columns_to_types,
+            unique_key=(exp.column("snapshot_name"), exp.column("snapshot_version")),
         )
 
     def count(self) -> int:
diff --git a/tests/core/engine_adapter/integration/test_integration_postgres.py b/tests/core/engine_adapter/integration/test_integration_postgres.py
index 863aae55a4..82172378ae 100644
--- a/tests/core/engine_adapter/integration/test_integration_postgres.py
+++ b/tests/core/engine_adapter/integration/test_integration_postgres.py
@@ -2,7 +2,6 @@
 import pytest
 from pytest import FixtureRequest
 from sqlmesh.core.engine_adapter import PostgresEngineAdapter
-from tests.core.engine_adapter.integration import TestContext
 
 from tests.core.engine_adapter.integration import (
     TestContext,
@@ -29,3 +28,8 @@ def engine_adapter(ctx: TestContext) -> PostgresEngineAdapter:
 def test_engine_adapter(ctx: TestContext):
     assert isinstance(ctx.engine_adapter, PostgresEngineAdapter)
     assert ctx.engine_adapter.fetchone("select 1") == (1,)
+
+
+def test_server_version_psycopg(ctx: TestContext):
+    assert isinstance(ctx.engine_adapter, PostgresEngineAdapter)
+    assert ctx.engine_adapter.server_version != (0, 0)
diff --git a/tests/core/engine_adapter/test_postgres.py b/tests/core/engine_adapter/test_postgres.py
index f013914c3e..fd6ce44994 100644
--- a/tests/core/engine_adapter/test_postgres.py
+++ b/tests/core/engine_adapter/test_postgres.py
@@ -94,7 +94,7 @@ def test_create_table_like(make_mocked_engine_adapter: t.Callable):
 
 def test_merge_version_gte_15(make_mocked_engine_adapter: t.Callable):
     adapter = make_mocked_engine_adapter(PostgresEngineAdapter)
-    adapter._connection_pool.get().server_version = 150000
+    adapter.server_version = (15, 0)
 
     adapter.merge(
         target_table="target",
@@ -117,7 +117,7 @@ def test_merge_version_lt_15(
     make_mocked_engine_adapter: t.Callable, make_temp_table_name: t.Callable, mocker: MockerFixture
 ):
     adapter = make_mocked_engine_adapter(PostgresEngineAdapter)
-    adapter._connection_pool.get().server_version = 140000
+    adapter.server_version = (14, 0)
 
     temp_table_mock = mocker.patch("sqlmesh.core.engine_adapter.EngineAdapter._get_temp_table")
     table_name = "test"
@@ -161,3 +161,19 @@ def table_columns(table_name: str) -> t.Dict[str, exp.DataType]:
     assert to_sql_calls(adapter) == [
         'ALTER TABLE "test_table" DROP COLUMN "test_column" CASCADE',
     ]
+
+
+def test_server_version(make_mocked_engine_adapter: t.Callable, mocker: MockerFixture):
+    adapter = make_mocked_engine_adapter(PostgresEngineAdapter)
+
+    fetchone_mock = mocker.patch.object(adapter, "fetchone")
+    fetchone_mock.return_value = ("14.0",)
+    assert adapter.server_version == (14, 0)
+
+    del adapter.server_version
+    fetchone_mock.return_value = ("15.8",)
+    assert adapter.server_version == (15, 8)
+
+    del adapter.server_version
+    fetchone_mock.return_value = ("15.13 (Debian 15.13-1.pgdg120+1)",)
+    assert adapter.server_version == (15, 13)