Shut down if no connected users (AUTO_CLOSE)
When this option is enabled, the database is closed and shut down when the last user of the database exits and all processes in the database complete, thereby freeing any resources. The database reopens automatically when a user tries to use the database again. When disabled, the database remains open even if no users are currently using the database.
Auto create statistics on columns in predicates (AUTO_CREATE_STATISTICS)
When this option is enabled, statistics are automatically created on columns used in a predicate. Adding statistics improves query performance because the SQL Server query optimizer can better determine how to evaluate a query. If the statistics are not used, SQL Server automatically deletes them. When disabled, statistics are not automatically created; instead, statistics can be manually created.
Auto update statistics when out-of-date (AUTO_UPDATE_STATISTICS)
When this option is enabled, existing statistics are automatically updated when the statistics become out-of-date because the data in the tables have been changed. When disabled, existing statistics are not automatically updated; instead, statistics can be manually updated.
Asynchronous update (AUTO_UPDATE_STATISTICS_ASYNC)
When this option is enabled, queries do not wait for the statistics to be updated before compiling. Instead, the out-of-date statistics are put on a queue for updating by a worker thread in a background process. The query and any other concurrent queries compile immediately by using the existing out-of-date statistics.
Auto shrink data and log files (AUTO_SHRINK)
When this option is enabled, the database files are candidates for periodic shrinking. Both data files and log files can be shrunk automatically by SQL Server. AUTO_SHRINK reduces the size of the transaction log only if the database is set to SIMPLE recovery model or if the log is backed up. When disabled, the database files are not automatically shrunk during periodic checks for unused space.