How to reduce the number of extents to one per Storage Area

How to reduce the number of database extents to one per Storage Area ?

Method 1:  PROREST

If single area extents need to be restored to the same directory, ensure no structure file (dbname.st) exists in that directory and run the PROREST command. Where 'dbname' is the name used in the PROREST command for the restored database name. When a dbname.st file does not exist in the restore directory, the PROREST command will automatically create a database structure based on the backup file instead, with one variable extent per area in the current directory.  

If the single area extents need to be restored to different directories, then place a structure file in the restore target directory (dbname.st) defining the full paths to where each area extent needs to be restored and run the PROREST command.

Method 2: PROCOPY / PRODB

When a structure file does not exist in the target directory, PROCOPY will create the target database using the Storage Area structure of the source database and will place all of the area/extents in the same directory as the target database structure (.db) file, even when the source database resides in multiple directories, resulting in multiple extents per area.  

If single area extents need to be restored to the same directory or different directories, place a structure file in the target directory (dbname.st) defining the full paths to where each area extent needs to be restored and run the PROCOPY or PRODB command.

Method 3: Dump and Load

The advantage of a dump and load strategy, is that database objects can be re-organised into different single area allocations or loaded into their existing areas with better record per block alignments.

Largefile considerations

If the source database already has the largefiles feature enabled, refer to Article P98733, How do prorest and procopy work with Large File Support?   

The structure used will first need to have the largefiles feature enabled if

• Any of the database objects or combination of database object assigned to a given area with a single extent, exceed 2GB. 
• The database may have multiple extents in an Area that in total exceed 2GB, in order for the single area extent to grow beyond 2GB.
• The largefiles feature is only available with Enterprise Database Licenses and Progress versions 9.1D and above.  

Typically this means that not only an existing .st file needs to be in the target directory, but a void database structure with the same database blocksize as the source database must exist with the largefiles feature set, prior to the method employed.