1.1 KiB
1.1 KiB
Create overviews for vector dataset.
Using the function
The table for which overviews will be generated should be a Cartodbfied dataset with vector geometry.
SELECT CDB_CreateOverviews('table_name');
--- Generates overview tables for the dataset
Arguments
CDB_CreateOverviews(table_name, ref_z_strategy, reduction_strategy)
- table_name regclass, table for which overviews will be generated
- ref_z_strategy regproc, function that provides the Z-scale strategy.
It returns the base Z level for the dataset.
It should have these arguments:
- table_name regclass, table to compute the reference Z scale for
- reduction_strategy regproc, function that provides the reduction strategy
to generate an overview table from a table for a smaller scale (higher Z number).
It returns the name of the generated table.
It should have these arguments:
- base_table_name regclass, base table to be reduced.
- base_z integer, base Z level assigned to the base table.
- overview_z integer, Z level for which to generate the overview.