Cloudscape Properties
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cloudscape.storage.pageReservedSpace

Function

Defines the percentage of space reserved for updates on an on-disk database page for tables only (not indexes); indicates the percentage of space to keep free on a page when inserting. Leaving reserved space on a page can minimize row overflow (and the associated performance hit) during updates. Once a page has been filled up to the reserved-space threshold, no new rows are allowed on the page. This reserved space is used only for rows that increase in size when updated, not for new inserts.

Regardless of the value of cloudscape.storage.pageReservedSpace, an empty page always accepts at least one row.

Valid Conglomerates

Tables only.

Default

20%.

Minimum Value

The minimum value is 0% and the maximum is 100%. If you specify a value outside this range, Cloudscape uses the default value of 20%.

Example

-- modifying the default for the system
cloudscape.storage.pageReservedSpace=40

-- modifying the default for the database
CALL PropertyInfo.setDatabaseProperty(
    'cloudscape.storage.pageReservedSpace',
    '40')

-- overriding the defaults for a single table
CREATE TABLE B(textcol LONG VARCHAR)
PROPERTIES cloudscape.storage.pageReservedSpace=40

Scope

system-wide

database-wide

conglomerate-specific

Dynamic or Static

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