Always treat RETURNING as supported by SQL engines (#19047)

AndrewFerr · web-flow · commit 9d81bb703c2d · 2025-10-24T13:21:49.000-05:00
Can do this now that SQLite 3.35.0 added support for `RETURNING`. > The RETURNING syntax has been supported by SQLite since version 3.35.0 (2021-03-12). > > *-- https://sqlite.org/lang_returning.html* This also bumps the minimum supported SQLite version according to Synapse's [deprecation policy](https://element-hq.github.io/synapse/latest/deprecation_policy.html#platform-dependencies). Fix #17577
diff --git a/.ci/scripts/calculate_jobs.py b/.ci/scripts/calculate_jobs.py
@@ -99,24 +99,24 @@ def set_output(key: str, value: str):
 
 # First calculate the various sytest jobs.
 #
-# For each type of test we only run on bullseye on PRs
+# For each type of test we only run on bookworm on PRs
 
 
 sytest_tests = [
     {
-        "sytest-tag": "bullseye",
+        "sytest-tag": "bookworm",
     },
     {
-        "sytest-tag": "bullseye",
+        "sytest-tag": "bookworm",
         "postgres": "postgres",
     },
     {
-        "sytest-tag": "bullseye",
+        "sytest-tag": "bookworm",
         "postgres": "multi-postgres",
         "workers": "workers",
     },
     {
-        "sytest-tag": "bullseye",
+        "sytest-tag": "bookworm",
         "postgres": "multi-postgres",
         "workers": "workers",
         "reactor": "asyncio",
@@ -127,11 +127,11 @@ def set_output(key: str, value: str):
     sytest_tests.extend(
         [
             {
-                "sytest-tag": "bullseye",
+                "sytest-tag": "bookworm",
                 "reactor": "asyncio",
             },
             {
-                "sytest-tag": "bullseye",
+                "sytest-tag": "bookworm",
                 "postgres": "postgres",
                 "reactor": "asyncio",
             },
diff --git a/.github/workflows/latest_deps.yml b/.github/workflows/latest_deps.yml
@@ -139,9 +139,9 @@ jobs:
       fail-fast: false
       matrix:
         include:
-          - sytest-tag: bullseye
+          - sytest-tag: bookworm
 
-          - sytest-tag: bullseye
+          - sytest-tag: bookworm
             postgres: postgres
             workers: workers
             redis: redis
diff --git a/.github/workflows/twisted_trunk.yml b/.github/workflows/twisted_trunk.yml
@@ -108,11 +108,11 @@ jobs:
     if: needs.check_repo.outputs.should_run_workflow == 'true'
     runs-on: ubuntu-latest
     container:
-      # We're using debian:bullseye because it uses Python 3.9 which is our minimum supported Python version.
+      # We're using bookworm because that's what Debian oldstable is at the time of writing.
       # This job is a canary to warn us about unreleased twisted changes that would cause problems for us if
       # they were to be released immediately. For simplicity's sake (and to save CI runners) we use the oldest
       # version, assuming that any incompatibilities on newer versions would also be present on the oldest.
-      image: matrixdotorg/sytest-synapse:bullseye
+      image: matrixdotorg/sytest-synapse:bookworm
       volumes:
         - ${{ github.workspace }}:/src
 
diff --git a/changelog.d/19047.doc b/changelog.d/19047.doc
@@ -0,0 +1 @@
+Update the link to the Debian oldstable package for SQLite.
diff --git a/changelog.d/19047.misc b/changelog.d/19047.misc
@@ -0,0 +1 @@
+Always treat `RETURNING` as supported by SQL engines, now that the minimum-supported versions of both SQLite and PostgreSQL support it.
diff --git a/changelog.d/19047.removal b/changelog.d/19047.removal
@@ -0,0 +1 @@
+Remove support for SQLite < 3.37.2.
diff --git a/docs/deprecation_policy.md b/docs/deprecation_policy.md
@@ -21,7 +21,7 @@ people building from source should ensure they can fetch recent versions of Rust
 (e.g. by using [rustup](https://rustup.rs/)).
 
 The oldest supported version of SQLite is the version
-[provided](https://packages.debian.org/bullseye/libsqlite3-0) by
+[provided](https://packages.debian.org/oldstable/libsqlite3-0) by
 [Debian oldstable](https://wiki.debian.org/DebianOldStable).
 
 
diff --git a/docs/development/contributing_guide.md b/docs/development/contributing_guide.md
@@ -320,7 +320,7 @@ The following command will let you run the integration test with the most common
 configuration:
 
 ```sh
-$ docker run --rm -it -v /path/where/you/have/cloned/the/repository\:/src:ro -v /path/to/where/you/want/logs\:/logs matrixdotorg/sytest-synapse:bullseye
+$ docker run --rm -it -v /path/where/you/have/cloned/the/repository\:/src:ro -v /path/to/where/you/want/logs\:/logs matrixdotorg/sytest-synapse:bookworm
 ```
 (Note that the paths must be full paths! You could also write `$(realpath relative/path)` if needed.)
 
diff --git a/synapse/storage/database.py b/synapse/storage/database.py
@@ -1161,36 +1161,17 @@ def simple_insert_returning_txn(
         SQLite versions that don't support it).
         """
 
-        if txn.database_engine.supports_returning:
-            sql = "INSERT INTO %s (%s) VALUES(%s) RETURNING %s" % (
-                table,
-                ", ".join(k for k in values.keys()),
-                ", ".join("?" for _ in values.keys()),
-                ", ".join(k for k in returning),
-            )
-
-            txn.execute(sql, list(values.values()))
-            row = txn.fetchone()
-            assert row is not None
-            return row
-        else:
-            # For old versions of SQLite we do a standard insert and then can
-            # use `last_insert_rowid` to get at the row we just inserted
-            DatabasePool.simple_insert_txn(
-                txn,
-                table=table,
-                values=values,
-            )
-            txn.execute("SELECT last_insert_rowid()")
-            row = txn.fetchone()
-            assert row is not None
-            (rowid,) = row
+        sql = "INSERT INTO %s (%s) VALUES(%s) RETURNING %s" % (
+            table,
+            ", ".join(k for k in values.keys()),
+            ", ".join("?" for _ in values.keys()),
+            ", ".join(k for k in returning),
+        )
 
-            row = DatabasePool.simple_select_one_txn(
-                txn, table=table, keyvalues={"rowid": rowid}, retcols=returning
-            )
-            assert row is not None
-            return row
+        txn.execute(sql, list(values.values()))
+        row = txn.fetchone()
+        assert row is not None
+        return row
 
     async def simple_insert_many(
         self,
diff --git a/synapse/storage/databases/main/delayed_events.py b/synapse/storage/databases/main/delayed_events.py
@@ -347,33 +347,28 @@ def process_target_delayed_event_txn(
             EventDetails,
             Optional[Timestamp],
         ]:
-            sql_cols = ", ".join(
-                (
-                    "room_id",
-                    "event_type",
-                    "state_key",
-                    "origin_server_ts",
-                    "content",
-                    "device_id",
-                )
-            )
-            sql_update = "UPDATE delayed_events SET is_processed = TRUE"
-            sql_where = "WHERE delay_id = ? AND user_localpart = ? AND NOT is_processed"
-            sql_args = (delay_id, user_localpart)
             txn.execute(
+                """
+                UPDATE delayed_events
+                SET is_processed = TRUE
+                WHERE delay_id = ? AND user_localpart = ?
+                    AND NOT is_processed
+                RETURNING
+                    room_id,
+                    event_type,
+                    state_key,
+                    origin_server_ts,
+                    content,
+                    device_id
+                """,
                 (
-                    f"{sql_update} {sql_where} RETURNING {sql_cols}"
-                    if self.database_engine.supports_returning
-                    else f"SELECT {sql_cols} FROM delayed_events {sql_where}"
+                    delay_id,
+                    user_localpart,
                 ),
-                sql_args,
             )
             row = txn.fetchone()
             if row is None:
                 raise NotFoundError("Delayed event not found")
-            elif not self.database_engine.supports_returning:
-                txn.execute(f"{sql_update} {sql_where}", sql_args)
-                assert txn.rowcount == 1
 
             event = EventDetails(
                 RoomID.from_string(row[0]),
diff --git a/synapse/storage/databases/main/event_federation.py b/synapse/storage/databases/main/event_federation.py
@@ -2040,61 +2040,29 @@ async def remove_received_event_from_staging(
         Returns:
             The received_ts of the row that was deleted, if any.
         """
-        if self.db_pool.engine.supports_returning:
 
-            def _remove_received_event_from_staging_txn(
-                txn: LoggingTransaction,
-            ) -> Optional[int]:
-                sql = """
-                    DELETE FROM federation_inbound_events_staging
-                    WHERE origin = ? AND event_id = ?
-                    RETURNING received_ts
-                """
-
-                txn.execute(sql, (origin, event_id))
-                row = cast(Optional[tuple[int]], txn.fetchone())
-
-                if row is None:
-                    return None
-
-                return row[0]
-
-            return await self.db_pool.runInteraction(
-                "remove_received_event_from_staging",
-                _remove_received_event_from_staging_txn,
-                db_autocommit=True,
-            )
+        def _remove_received_event_from_staging_txn(
+            txn: LoggingTransaction,
+        ) -> Optional[int]:
+            sql = """
+                DELETE FROM federation_inbound_events_staging
+                WHERE origin = ? AND event_id = ?
+                RETURNING received_ts
+            """
 
-        else:
+            txn.execute(sql, (origin, event_id))
+            row = cast(Optional[tuple[int]], txn.fetchone())
 
-            def _remove_received_event_from_staging_txn(
-                txn: LoggingTransaction,
-            ) -> Optional[int]:
-                received_ts = self.db_pool.simple_select_one_onecol_txn(
-                    txn,
-                    table="federation_inbound_events_staging",
-                    keyvalues={
-                        "origin": origin,
-                        "event_id": event_id,
-                    },
-                    retcol="received_ts",
-                    allow_none=True,
-                )
-                self.db_pool.simple_delete_txn(
-                    txn,
-                    table="federation_inbound_events_staging",
-                    keyvalues={
-                        "origin": origin,
-                        "event_id": event_id,
-                    },
-                )
+            if row is None:
+                return None
 
-                return received_ts
+            return row[0]
 
-            return await self.db_pool.runInteraction(
-                "remove_received_event_from_staging",
-                _remove_received_event_from_staging_txn,
-            )
+        return await self.db_pool.runInteraction(
+            "remove_received_event_from_staging",
+            _remove_received_event_from_staging_txn,
+            db_autocommit=True,
+        )
 
     async def get_next_staged_event_id_for_room(
         self,
diff --git a/synapse/storage/databases/main/registration.py b/synapse/storage/databases/main/registration.py
@@ -2544,31 +2544,13 @@ def user_delete_access_tokens_for_devices_txn(
             )
             args.append(user_id)
 
-            if self.database_engine.supports_returning:
-                sql = f"""
-                    DELETE FROM access_tokens
-                    WHERE {clause} AND user_id = ?
-                    RETURNING token, id, device_id
-                """
-                txn.execute(sql, args)
-                tokens_and_devices = txn.fetchall()
-            else:
-                tokens_and_devices = self.db_pool.simple_select_many_txn(
-                    txn,
-                    table="access_tokens",
-                    column="device_id",
-                    iterable=batch_device_ids,
-                    keyvalues={"user_id": user_id},
-                    retcols=("token", "id", "device_id"),
-                )
-
-                self.db_pool.simple_delete_many_txn(
-                    txn,
-                    table="access_tokens",
-                    keyvalues={"user_id": user_id},
-                    column="device_id",
-                    values=batch_device_ids,
-                )
+            sql = f"""
+                DELETE FROM access_tokens
+                WHERE {clause} AND user_id = ?
+                RETURNING token, id, device_id
+            """
+            txn.execute(sql, args)
+            tokens_and_devices = txn.fetchall()
 
             self._invalidate_cache_and_stream_bulk(
                 txn,
diff --git a/synapse/storage/databases/main/user_directory.py b/synapse/storage/databases/main/user_directory.py
@@ -353,27 +353,19 @@ async def _populate_user_directory_process_users(
         def _populate_user_directory_process_users_txn(
             txn: LoggingTransaction,
         ) -> Optional[int]:
-            if self.database_engine.supports_returning:
-                # Note: we use an ORDER BY in the SELECT to force usage of an
-                # index. Otherwise, postgres does a sequential scan that is
-                # surprisingly slow (I think due to the fact it will read/skip
-                # over lots of already deleted rows).
-                sql = f"""
-                    DELETE FROM {TEMP_TABLE + "_users"}
-                    WHERE user_id IN (
-                        SELECT user_id FROM {TEMP_TABLE + "_users"} ORDER BY user_id LIMIT ?
-                    )
-                    RETURNING user_id
-                """
-                txn.execute(sql, (batch_size,))
-                user_result = cast(list[tuple[str]], txn.fetchall())
-            else:
-                sql = "SELECT user_id FROM %s ORDER BY user_id LIMIT %s" % (
-                    TEMP_TABLE + "_users",
-                    str(batch_size),
+            # Note: we use an ORDER BY in the SELECT to force usage of an
+            # index. Otherwise, postgres does a sequential scan that is
+            # surprisingly slow (I think due to the fact it will read/skip
+            # over lots of already deleted rows).
+            sql = f"""
+                DELETE FROM {TEMP_TABLE + "_users"}
+                WHERE user_id IN (
+                    SELECT user_id FROM {TEMP_TABLE + "_users"} ORDER BY user_id LIMIT ?
                 )
-                txn.execute(sql)
-                user_result = cast(list[tuple[str]], txn.fetchall())
+                RETURNING user_id
+            """
+            txn.execute(sql, (batch_size,))
+            user_result = cast(list[tuple[str]], txn.fetchall())
 
             if not user_result:
                 return None
@@ -432,17 +424,6 @@ def _populate_user_directory_process_users_txn(
             # Actually insert the users with their profiles into the directory.
             self._update_profiles_in_user_dir_txn(txn, profiles_to_insert)
 
-            # We've finished processing the users. Delete it from the table, if
-            # we haven't already.
-            if not self.database_engine.supports_returning:
-                self.db_pool.simple_delete_many_txn(
-                    txn,
-                    table=TEMP_TABLE + "_users",
-                    column="user_id",
-                    values=users_to_work_on,
-                    keyvalues={},
-                )
-
             # Update the remaining counter.
             progress["remaining"] -= len(users_to_work_on)
             self.db_pool.updates._background_update_progress_txn(
diff --git a/synapse/storage/engines/_base.py b/synapse/storage/engines/_base.py
@@ -63,12 +63,6 @@ def supports_using_any_list(self) -> bool:
         """
         ...
 
-    @property
-    @abc.abstractmethod
-    def supports_returning(self) -> bool:
-        """Do we support the `RETURNING` clause in insert/update/delete?"""
-        ...
-
     @abc.abstractmethod
     def check_database(
         self, db_conn: ConnectionType, allow_outdated_version: bool = False
diff --git a/synapse/storage/engines/postgres.py b/synapse/storage/engines/postgres.py
@@ -193,11 +193,6 @@ def supports_using_any_list(self) -> bool:
         """Do we support using `a = ANY(?)` and passing a list"""
         return True
 
-    @property
-    def supports_returning(self) -> bool:
-        """Do we support the `RETURNING` clause in insert/update/delete?"""
-        return True
-
     def is_deadlock(self, error: Exception) -> bool:
         if isinstance(error, psycopg2.DatabaseError):
             # https://www.postgresql.org/docs/current/static/errcodes-appendix.html
diff --git a/synapse/storage/engines/sqlite.py b/synapse/storage/engines/sqlite.py

Original file line number	Diff line number	Diff line change
`@@ -99,24 +99,24 @@ def set_output(key: str, value: str):`
`99`	`99`
`100`	`100`	`# First calculate the various sytest jobs.`
`101`	`101`	`#`
`102`		`-# For each type of test we only run on bullseye on PRs`
	`102`	`+# For each type of test we only run on bookworm on PRs`
`103`	`103`
`104`	`104`
`105`	`105`	`sytest_tests = [`
`106`	`106`	`{`
`107`		`- "sytest-tag": "bullseye",`
	`107`	`+ "sytest-tag": "bookworm",`
`108`	`108`	`},`
`109`	`109`	`{`
`110`		`- "sytest-tag": "bullseye",`
	`110`	`+ "sytest-tag": "bookworm",`
`111`	`111`	`"postgres": "postgres",`
`112`	`112`	`},`
`113`	`113`	`{`
`114`		`- "sytest-tag": "bullseye",`
	`114`	`+ "sytest-tag": "bookworm",`
`115`	`115`	`"postgres": "multi-postgres",`
`116`	`116`	`"workers": "workers",`
`117`	`117`	`},`
`118`	`118`	`{`
`119`		`- "sytest-tag": "bullseye",`
	`119`	`+ "sytest-tag": "bookworm",`
`120`	`120`	`"postgres": "multi-postgres",`
`121`	`121`	`"workers": "workers",`
`122`	`122`	`"reactor": "asyncio",`
`@@ -127,11 +127,11 @@ def set_output(key: str, value: str):`
`127`	`127`	`sytest_tests.extend(`
`128`	`128`	`[`
`129`	`129`	`{`
`130`		`- "sytest-tag": "bullseye",`
	`130`	`+ "sytest-tag": "bookworm",`
`131`	`131`	`"reactor": "asyncio",`
`132`	`132`	`},`
`133`	`133`	`{`
`134`		`- "sytest-tag": "bullseye",`
	`134`	`+ "sytest-tag": "bookworm",`
`135`	`135`	`"postgres": "postgres",`
`136`	`136`	`"reactor": "asyncio",`
`137`	`137`	`},`
Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	`+Update the link to the Debian oldstable package for SQLite.`
Original file line number	Diff line number	Diff line change
`@@ -0,0 +1 @@`
	`1`	+Always treat `RETURNING` as supported by SQL engines, now that the minimum-supported versions of both SQLite and PostgreSQL support it.