diff --git a/scripts-available/CDB_Overviews.sql b/scripts-available/CDB_Overviews.sql index e1da1fe..a72d48d 100644 --- a/scripts-available/CDB_Overviews.sql +++ b/scripts-available/CDB_Overviews.sql @@ -1,3 +1,40 @@ +-- Calculate the estimated extent of a cartodbfy'ed table. +-- Scope: private. +-- Parameters +-- reloid: oid of the input table. +-- Return value A box2d extent in 3857. +CREATE OR REPLACE FUNCTION _cdb_estimated_extent(reloid REGCLASS) +RETURNS box2d +AS $$ + DECLARE + ext box2d; + ext_query text; + table_id record; + BEGIN + + SELECT n.nspname AS schema_name, c.relname table_name INTO STRICT table_id + FROM pg_class c JOIN pg_namespace n on n.oid = c.relnamespace WHERE c.oid = reloid::oid; + + ext_query = format( + 'SELECT ST_EstimatedExtent(''%1$I'', ''%2$I'', ''%3$I'');', + table_id.schema_name, table_id.table_name, 'the_geom_webmercator' + ); + + BEGIN + EXECUTE ext_query INTO ext; + EXCEPTION + -- This is the typical ERROR: stats for "mytable" do not exist + WHEN internal_error THEN + -- Get stats and execute again + EXECUTE format('ANALYZE %1$I', reloid); + EXECUTE ext_query INTO ext; + END; + + RETURN ext; + END; +$$ LANGUAGE PLPGSQL VOLATILE; + + -- Determine the max feature density of a given dataset. -- Scope: private. -- Parameters