The directives that are processed by the SDF writer are listed below. The suffixes shown are prefixed by the current <WriterKeyword>_ in a mapping file. By default, the <WriterKeyword> for the SDF writer is SDF.
DATASET
Required/Optional: Required
The value for this keyword is the name of the created SDF folder. If a folder of this name exists, it is replaced by the new SDF. A typical mapping file fragment specifying an output SDF dataset looks like:
SDF_DATASET /tmp
APPEND
Required/Optional: Optional
This directive indicates whether or not the writer will append to existing SDF files. An example use of this directive is:
SDF_APPEND yes
DEF
Required/Optional: Required
The SDF writer uses SDF_DEF lines to define files to write features to. A typical mapping file fragment specifying an output SDF file looks like:
SDF_DEF roads
CREATE_KIF
Required/Optional: Optional
This directive controls whether or not a key index file will be created along with the SDF file. If an existing SDF file is being appended to, this flag is ignored. An example specification is:
SDF_CREATE_KIF yes
KEY_MAX_LEN
Required/Optional: Optional
This directive is only used when a key index file is being created, and sets the maximum length of the values expected to be found in the sdf_key attribute. For example:
SDF_KEY_MAX_LEN 65
PRECISION
Required/Optional: Optional
This directive sets the number of bits of accuracy which will be stored for each coordinate output. If an existing SDF file is being appended to, it is ignored and the precision is set to pre-existing precision. An example specification is:
SDF_PRECISION 64