Please use the links in the table below to view the eXtremeSQL aggregate functions:
backup(<dbsFile>, <logFile>, <nThreads>) Copy .dbs and .log files to dbsFile and logFile accordingly using nThreads threads. (Supported only for disk-based databases: config(name, value) Sets a new configuration parameter value and returns the old value. If
value
is null, then the parameter is not changed and only the current value is returned. The following parameters are currently supported:
batch.buf.size [integer]
- size of buffer (number of elements) used for batch insertbulk.page.write [boolean]
- bulk page write mode: instead of writing indidual dirty page thrown away from page pool, sort ad write all dirty page (for disk database only)mursiw.commit.optimization [boolean]
- release transactions lock as soon as possible (for disk database only)index.optimistic.lock.threshold [integer]
- maximum number of active write transactions when optimistic locking of B-Tree indexes can be performedallocation.bitmap.caching.priority [integer]
- disk page pool priority for allocation bitmap pagesindex.caching.priority [integer]
- disk page pool priority for index pagesobject.caching.priority [integer]
- disk page pool priority for object pagessave_dictionary(<filename>) Saves the database metadata in xSQL config format (JSON) to <filename> save_metadata(<filename>) Saves the database metadata in xSQL config format (JSON) to <filename> save_snapshot(<filename>) Saves the database image (calling C API mco_db_save()
) to specified <filename>set_free_memory_threshold(<size>) Set the limit for free database memory. If the limit is reached, the current transaction is aborted (rolled back). xSQL sets the threshold to 4Mb by default. This function changes the limit only for the current connection. tl_save(<snapshotName>) Saves a database snapshot to <snapshotName> and truncates the log. This function is available only for databases created by xSQL with TL support enabled. Returns error code (0 means OK) tl_start(<snapshotName>) Starts Transaction Logging (TL). This function is available only for databases created by xSQL with TL support enabled. <snapshotName> is the file name to save the initial database snapshot. Returns error code (0 means OK) tl_stop() Stops Transaction Logging (TL). This function is available only for databases created by xSQL with TL support enabled. Returns error code (0 means OK)