SQL/MP Reference Manual

HP NonStop SQL/MP Reference Manual—523352-013

A-7

ALLOCATE File Attribute

ALLOCATE is a Guardian file attribute that reserves disk space for a file, or frees disk

space previously reserved for a file that does not contain data. ALLOCATE applies to

key-sequenced, relative, and entry-sequenced tables and indexes.

Allocating disk space in advance ensures that space is available when needed and

avoids processing errors caused by full or fragmented disks during normal

allocation-on-demand.

ALLOCATE num-extents

specifies the number of extents to allocate in advance. The number must be an

integer between 1 and the current value of the MAXEXTENTS file attribute.

Depending on your file configuration, you might not be able to allocate the full

number of MAXEXTENTS.

For ALTER TABLE or ALTER INDEX, ALLOCATE allocates new extents until the

total of new and existing extents equals the specified number.

DEALLOCATE

frees all unused allocated extents (that is, all allocated extents beyond the extent

that contains the end-of-file). DEALLOCATE is valid only for ALTER TABLE or

ALTER INDEX.

Considerations—ALLOCATE



ALLOCATE and DEALLOCATE apply to all partitions of the specified file unless

you include a PARTONLY clause on the statement that specifies the file attribute.

Use the PARTONLY clause if you want to specify different numbers of extents for

different partitions:



In a CREATE TABLE statement that defines the primary partition and four

secondary partitions, ALLOCATE 40 allocates 40 extents to each of the five

partitions.



In an ALTER TABLE statement that specifies PARTONLY, ALLOCATE 40

allocates additional extents so that the specified partition has a total of 40

extents.



In an ALTER TABLE statement that does not specify PARTONLY, ALLOCATE

40 allocates additional extents to each partition whose total is less than 40 to

make the number of extents equal to 40. ALLOCATE has no effect on partitions

with 40 or more extents.

{ ALLOCATE num-extents }

{ DEALLOCATE }

The default is ALLOCATE 0.