You can set a tablespace to automatically extcnd itself by a spccified amount when it reaches its size limit. If you do not enable autocxtcnd. then you arc alcrted when the tablespace reaches its critical or warning thrcshold size. The critical and warning threshold paramctcrs havc default valucs that you can change at any timc. Thcse parameters also cause alerts to be gencrated for autoextending tablespaces that are approaching their specified size limit. You can rcspond to size alerts by manually increasing the tablespace size. You do so by increasing the size of one or morę of the tablespace data files or by adding another data file to the tablespace.