Use ST_BuildPyramid to create a vector pyramid-PolarDB(PolarDB)-阿里云帮助中心

Syntax

boolean ST_BuildPyramid(cstring table, cstring geom, cstring fid, cstring config)

Parameters

Parameter	Description
table	The name of the spatial geometry table.
geom	The name of the geometry field.
fid	The name of the feature ID field.
config	The parameters for creating the pyramid, as a JSON string.

configThe following table describes the parameters.

Parameter	Type	Default value	Description
name	string	Same as table name	The name of the pyramid.
parallel	int	0	The number of parallel build tasks. You must set the max_prepared_transactions parameter. 0 indicates maximum parallelism.
tileSize	int	1024	The tile size. Must be > 0 and < 4096.
tileExtend	int	8	The tile padding. Must be > 0.
userExtent	array[double]	null	Custom geographic extent. Set [] with values: minx, miny, maxx, maxy.
splitSize	int	10000	The maximum number of features that determine index node splitting. A larger value results in a sparser pyramid.
maxLevel	int	16	Max pyramid level. Valid values: 0-20.
sourceSRS	int	-1	The coordinate system of the source data. If not set, the SRID of the metadata is read.
destSRS	int	3857	The EPSG code of the output tile coordinate reference system. Only 3857 and 4326 are supported.
updateExtentSRS	int	4326	The EPSG format used for the update range of the pyramid update function. For details, see the description of the ST_UpdatePyramid function.
updateBoxScale	int	10	Affects the precision of the pyramid update operation. For details, see the description of the ST_UpdatePyramid function.
buildRules	array[object]	null	Build rules. Each object contains level and value values.
└level	array[int]	null	Levels to which the rule applies.
└value	object	null	Build rule value.
└filter	string	""	Filter expression using PostgreSQL query syntax.
└attrFields	array[string]	null	Attribute field names in MVT output.
└merge	array[string]	null	Filter conditions for grouping and merging.

configExample:

{
   "name" : "hello",           
   "parallel": 4,         
   "tileSize": 512,           
   "tileExtend": 8,
   "userExtent": [-180,-90,180,90],
   "splitSize": 5000,
   "maxLevel": 16,  
   "destSRS": 3857,
   "buildRules": [             
     {
       "level": [0,1,2],  
       "value": {
         "filter": "code!=0",
         "attrFields": ["name","color"],    
         "merge":["code=1"]
       }
     }
   ]
}

Example

-- Create a vector pyramid for the spatial geometry table roads.
select ST_BuildPyramid('roads', 'geom', 'id', '');
st_buildpyramid
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