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derby.storage.minimumRecordSize

derby.storage.minimumRecordSize

Indicates the minimum user row size in bytes for on-disk database pages for tables when you are creating a table. This property ensures that there is enough room for a row to grow on a page when updated without having to overflow. This is generally most useful for VARCHAR and VARCHAR FOR BIT DATA data types and for tables that are updated a lot, in which the rows start small and grow due to updates. Reserving the space at the time of insertion minimizes row overflow due to updates, but it can result in wasted space. Set the property prior to issuing the CREATE TABLE statement.

See also derby.storage.pageReservedSpace.

Valid conglomerates

Tables only.

Default

12 bytes.

Minimum value

12 bytes.

Maximum value

derby.storage.pageSize * (1 - derby.storage.pageReservedSpace/100) - 100.

If you set this property to a value outside the legal range, Derby uses the default value.

Examples

-- changing the default for the system 
derby.storage.minimumRecordSize=128
 -- changing the default for the database 
CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY( 
    'derby.storage.minimumRecordSize',
    '128')

Dynamic or static

This property is dynamic; if you change it while Derby is running, the change takes effect immediately. For information about dynamic changes to properties, see Dynamic or Static Changes to Properties.


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