Specifies the type of data compression to be done on sequential and indexed files.
Syntax:
>>-.---.-.-----DATACOMPRESS--"integer"-.---><
+-/-+ +-NO--DATACOMPRESS------------+
Parameters:
- integer
- Must be one of:
- 0
- Equivalent to NODATACOMPRESS
- 1
- Specifies run-length encoding.
- 3
- Specifies run-length encoding for double-byte (DBCS) characters
- 128 through 255
- User-defined compression routines
Properties:
| Default:
|
DATACOMPRESS"0"
|
| Phase:
|
Syntax check
|
| $SET:
|
Any
|
Comments:
The only values that can be specified for data compression supported by this system are 0, 1 and 3. Values in the range 128 through 255 indicate user-defined compression routines.
You need to specify data compression only when creating the file. Subsequently, the data compression is detected when the file is opened.
To get data compression on an individual file, use $SET statements in your source so that this directive is in effect only for the part of the source containing the file's SELECT statement.
Data compression is supported only by the Callable File Handler. All indexed files are processed by the Callable File Handler. However, if you want to use data compression with sequential files, every program referencing those files must be compiled with the directive CALLFH"EXTFH".