|
|
|
The datacompress option indicates whether to create files with data compression enabled. When data compression is enabled, data records are compressed using the compression algorithm specified by the type attribute. Data compression reduces disk space utilization but it may also impact performance. This feature is turned off by default.
Note: If your configuration file does not include a datacompress element, the application can turn on compression programmatically for the files that need them. If you include this attribute in the configuration file, the setting will override programmatic requests from the application.
Accepted Values
Value |
Effect |
Synonyms |
|---|---|---|
yes |
Files are created with data compression enabled. This is the default value for RM/COBOL. |
y, true, on, 1 |
no |
Files are created without data compression. This is the default value for all file handlers except for RM/COBOL. |
n, false, off, 0 |
Attributes
Attribute |
Description |
Synonyms |
|---|---|---|
type |
Selects the type of compression. Values: "rle" : Use a simple RLE compression algorithm. "zlib" : Use the zlib compression algorithm (you will need to download the zlib library and place it in the local directory with the c-tree Server binary). The default value is "rle". |
|
strategy |
Selects the compression strategy. Depending on the compression type the possible values for strategy are: Valid values for type "rle": "0" : Use the default simple RLE compression strategy. Valid values for type "zlib": "0" : Use the default zlib compression strategy. "1" : Use the zlib filtered compression strategy. "2" : Use zlib Huffman only compression strategy. "3" : Use zlib RLE compression strategy. This is the default value. "4" : Use zlib fixed compression strategy. The default value is "0". |
|
level |
Selects the compression level. Valid values are 0 and the range between 1 and 9: "0" : Use the compression algorithm default level. "1" : Provides best speed but uses more disk space "9" : Provides best compression at the expense of performance. The default value is "0". |
|
Please refer to the zlib documentation available at http://zlib.net/manual.html for more information about zlib compression.
Note: The zlib library is not included with FairCom RTG. You will need to download the zlib library and place it in the local directory with the c-tree Server binary). If the FairCom RTG Server does not find ZLIB1.DLL in the path when it is started, an error 946 is returned when attempting to create files with zlib data compression.
Notice that the default for RM/COBOL is to create files with compression. Set datacompress to No if you do not want your RM/COBOL files to be compressed.
Examples
<datacompress type="rle" level="5">yes</datacompress>
<datacompress type="zlib" strategy="3" level="9">yes</datacompress>
<datacompress level="1">yes</datacompress>
