The
DB_VariableAreaExtentGrow Alert is an alert that is triggered when data is being written to a variable size database extent.
Variable size extents are often used to prevent the database from crashing when fixed size database extents get full.
The variable extent will then grow to 2GB and then the database will crash if it needs further space to write than available.
Unless an Enterprise Database License is in use and largefiles have been enabled, in which case the variable extent will grow to OS/filesystem/user limits if left unattended.
On older filesystems, writting to a variable size extent is slower than writing to a fixed size extent because a variable extent need to grow before each writing of new data to this variable extent and is therefore performance related.
Typically the
DB_AreaSpaceUtilizationHigh Alert is used to warn when Fixed extents are approaching capacity. Refer to Article
Extents DB_AreaSpaceUtilizationHigh alert When the
DB_VariableAreaExtentGrow Alert is enabled and triggered it is recommended to add additional fixed size extent(s) and a new reserve variable extent to accommodate future growth in the area:
