DEQ=

DEQ=

Tells OpenVMS how many disk blocks to add when it automatically extends a SAS data set during a write operation

Language element: data set option

Default: enough blocks for 5 data set pages

Engines: V6, V7, CONCUR

Valid as: data set option, engine or host option

OpenVMS specifics: All aspects are host-specific

Syntax
Details
Example
See Also

Syntax

DEQ=default-file-extension-quantity

default-file-extension-quantity: can range from 0 to 65,535 blocks. (A block is 512 bytes.) If you specify a value of 0, OpenVMS uses the process's default value. The default value is enough space for 5 pages.

Details

You should set the value to at least 10 percent of the normal data set size. A large value results in fewer file extensions during the life of the file; a small value results in many file extensions over the life of the file. Note that record access is slowed when a file has many noncontiguous file extensions.

Example

Suppose you specify the DEQ= data set option as follows:

libname test '[mydir]';
data test.a(alq=1000 deq=1000);
   . . . more data lines . . .
run;

Specifying DEQ=1000 indicates that if more space is needed for the file, that space is allocated in 1,000-block chunks. Note that OpenVMS always rounds the DEQ= value up to the next disk-cluster boundary.

See Also

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Language element:	data set option
Default:	enough blocks for 5 data set pages
Engines:	V6, V7, CONCUR
Valid as:	data set option, engine or host option
OpenVMS specifics:	All aspects are host-specific