This function creates an overview.

Syntax

raster ST_BuildOverview(cstring srcTableName, cstring srcColumnName, integer srcPyramidLevel, cstring chunkTableName);

Parameters

Parameter Description
tableName The name of the table.
columnName The name of the raster object column.
pyramidLevel The pyramid level of the overview to be created.
chunkTableName The name of the chunk table for storing the raster object created as an overview.

This function creates a table-based raster overview.

All the raster objects involved must meet the following requirements:
  • They have the same number of bands.
  • Either all or one of raster objects are geographically referenced. If all of them are geographically referenced, world coordinates (geographic coordinates) are used for the mosaic operation.
  • Their pixel types can be different. If world coordinates are used for the mosaic operation, they must have the same spatial reference system identifier (SRID) and pixel resolution.

Example

Insert into raster_table_overview values(1, ST_BuildOverview('raster_table','raster_obj', 0,'chunk_table_overview'));