This function compresses a pcpatch object based on the specified compression method.
Syntax
pcpatch ST_compress(pcpatch pc, text global_compression_schema default '', text compression_config default '');
Parameters
Parameter | Description |
---|---|
pc | The pcpatch object. |
global_compression_schema | The compression schema. |
compression_config | The compression configuration item that specifies the compression algorithm for specific dimensions. |
Description
Valid values of the global_compression_schema parameter include:
auto -- determined by pcid
dimension
laz -- no compression config supported
ght -- is discarded
If the global_compression_schema parameter is set to dimension, valid values of the compression_config parameter include:
auto -- determined automatically, from values stats
zlib -- deflate compression
sigbits -- significant bits removal
rle -- run-length encoding
Examples
SELECT ST_asText(ST_Compress(ST_MakePatch(1, ARRAY[-126.99,45.01,1,0, -126.98,45.02,2,0, -126.97,45.03,3,0])));
-------------------------------------------------
{"pcid":1,"pts":[
[-126.99,45.01,1,0],[-126.98,45.02,2,0],[-126.97,45.03,3,0]
]}