SQL/MX 2.x Reference Manual (H06.04+)

HP NonStop SQL/MX Reference Manual—540440-003
8-1
8 SQL/MX File Attributes
The ATTRIBUTE file option describes physical characteristics of files (including files
that contain tables, indexes, or partitions) that can affect the performance of
applications that use the files.
File attributes are set when a file (or an object that resides in a file) is created. If you do
not specify ATTRIBUTE values in the statement that creates an object (such as
CREATE TABLE or CREATE INDEX), NonStop SQL/MX uses default values for file
attributes.
Many file attributes can be changed later (with statements such as ALTER TABLE or
ALTER INDEX), some file attributes remain in effect for the life of the object, and a few
file attributes can change as a side effect of a command or a change to some other
attribute.
This section describes file attributes for SQL/MX objects:
For more information, see the separate entry for a specific attribute.
ALLOCATE/DEALLOCATE
on page 8-2
Reserves or frees disk space for a file.
AUDITCOMPRESS
on
page 8-3
Controls whether unchanged columns are included in audit
records.
BLOCKSIZE
on page 8-4 Sets size of data blocks. Default is 4096.
CLEARONPURGE
on
page 8-5
Controls disk erasure when file is dropped.
EXTENT
on page 8-6 Controls the size of extents.
MAXEXTENTS
on
page 8-7
Controls the number of extents.