Managing file and table sizes

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There are two ways maintain table sizes: setting up the Auto Increase parameters in the file so that free space is added to the tables as needed; or the File Manager may use a number of commands to maintain the table sizes.

The latter is described below.


Overview of Capabilities

Because of the hashed nature of Tables A and C, these tables can only be changed with the CREATE command during a file reorganisation.

The other tables may be modified using the INCREASE and DECREASE command, as follows:

Command Description Exclusive Access? Limitations
INCREASE dataset Add an additional dataset to a Model 204 file. No A model 204 file may have up to 255 datasets

The additional pages are formatted as free space

INCREASE TABLEB Move pages from free space to Table B No, but the DYNAMIC sub-parameter
is required if you don't have exclusive
access
segment boundaries need to be taken into account
the MAXINCBP parameter needs to be set if you wish to increase
Table B beyond the current segment boundary.
INCREASE TABLED
TABLEE or
TABLEX
Move pages from free space to this table No Up to maximum table size
DECREASE TABLEB
TABLED
TABLEE
TABLEX
Move pages to free space from the respective table Yes Only if the _HIGHPG statistic permits it


Increase Datasets

Increase Table B

Increase Other Tables

Decrease Table