diff options
Diffstat (limited to 'synapse/storage/background_updates.py')
| -rw-r--r-- | synapse/storage/background_updates.py | 98 |
1 files changed, 66 insertions, 32 deletions
diff --git a/synapse/storage/background_updates.py b/synapse/storage/background_updates.py index 813ad59e56..7157fb1dfb 100644 --- a/synapse/storage/background_updates.py +++ b/synapse/storage/background_updates.py @@ -210,7 +210,9 @@ class BackgroundUpdateStore(SQLBaseStore): self._background_update_handlers[update_name] = update_handler def register_background_index_update(self, update_name, index_name, - table, columns, where_clause=None): + table, columns, where_clause=None, + unique=False, + psql_only=False): """Helper for store classes to do a background index addition To use: @@ -226,48 +228,80 @@ class BackgroundUpdateStore(SQLBaseStore): index_name (str): name of index to add table (str): table to add index to columns (list[str]): columns/expressions to include in index + unique (bool): true to make a UNIQUE index + psql_only: true to only create this index on psql databases (useful + for virtual sqlite tables) """ - # if this is postgres, we add the indexes concurrently. Otherwise - # we fall back to doing it inline - if isinstance(self.database_engine, engines.PostgresEngine): - conc = True - else: - conc = False - # We don't use partial indices on SQLite as it wasn't introduced - # until 3.8, and wheezy has 3.7 - where_clause = None - - sql = ( - "CREATE INDEX %(conc)s %(name)s ON %(table)s (%(columns)s)" - " %(where_clause)s" - ) % { - "conc": "CONCURRENTLY" if conc else "", - "name": index_name, - "table": table, - "columns": ", ".join(columns), - "where_clause": "WHERE " + where_clause if where_clause else "" - } - - def create_index_concurrently(conn): + def create_index_psql(conn): conn.rollback() # postgres insists on autocommit for the index conn.set_session(autocommit=True) - c = conn.cursor() - c.execute(sql) - conn.set_session(autocommit=False) - def create_index(conn): + try: + c = conn.cursor() + + # If a previous attempt to create the index was interrupted, + # we may already have a half-built index. Let's just drop it + # before trying to create it again. + + sql = "DROP INDEX IF EXISTS %s" % (index_name,) + logger.debug("[SQL] %s", sql) + c.execute(sql) + + sql = ( + "CREATE %(unique)s INDEX CONCURRENTLY %(name)s" + " ON %(table)s" + " (%(columns)s) %(where_clause)s" + ) % { + "unique": "UNIQUE" if unique else "", + "name": index_name, + "table": table, + "columns": ", ".join(columns), + "where_clause": "WHERE " + where_clause if where_clause else "" + } + logger.debug("[SQL] %s", sql) + c.execute(sql) + finally: + conn.set_session(autocommit=False) + + def create_index_sqlite(conn): + # Sqlite doesn't support concurrent creation of indexes. + # + # We don't use partial indices on SQLite as it wasn't introduced + # until 3.8, and wheezy has 3.7 + # + # We assume that sqlite doesn't give us invalid indices; however + # we may still end up with the index existing but the + # background_updates not having been recorded if synapse got shut + # down at the wrong moment - hance we use IF NOT EXISTS. (SQLite + # has supported CREATE TABLE|INDEX IF NOT EXISTS since 3.3.0.) + sql = ( + "CREATE %(unique)s INDEX IF NOT EXISTS %(name)s ON %(table)s" + " (%(columns)s)" + ) % { + "unique": "UNIQUE" if unique else "", + "name": index_name, + "table": table, + "columns": ", ".join(columns), + } + c = conn.cursor() + logger.debug("[SQL] %s", sql) c.execute(sql) + if isinstance(self.database_engine, engines.PostgresEngine): + runner = create_index_psql + elif psql_only: + runner = None + else: + runner = create_index_sqlite + @defer.inlineCallbacks def updater(progress, batch_size): - logger.info("Adding index %s to %s", index_name, table) - if conc: - yield self.runWithConnection(create_index_concurrently) - else: - yield self.runWithConnection(create_index) + if runner is not None: + logger.info("Adding index %s to %s", index_name, table) + yield self.runWithConnection(runner) yield self._end_background_update(update_name) defer.returnValue(1) |