SQL/MP Reference Manual

HP NonStop SQL/MP Reference Manual—523352-013
D-68
DSLACK File Attribute
DSLACK File Attribute
DSLACK is a Guardian file attribute that specifies the minimum percentage of space to
leave for future insertions when loading data blocks. DSLACK applies only to
key-sequenced tables and to indexes.
percent
is an integer from 0 to 99 that specifies the percent of empty space to leave in
each data block when loading the file.
Considerations—DSLACK

DSLACK specifications are usually between 15 and 25 percent.

Specifying a larger-than-normal DSLACK value when a file is initially loaded and
many more inserts are expected can improve performance by reducing the number
of block splits required when inserts occur.

For a file expected to have little write activity, you can save disk space by
specifying a smaller-than-normal DSLACK value.
DSLACK percent
The default is the value of the SLACK file attribute.
The default for SLACK is 15 percent.