cartodb-postgresql/scripts-available/CDB_FederatedServerListRemote.sql

300 lines
12 KiB
PL/PgSQL

--------------------------------------------------------------------------------
-- Private functions
--------------------------------------------------------------------------------
--
-- List the schemas of a remote PG server
--
CREATE OR REPLACE FUNCTION @extschema@.__CDB_FS_List_Foreign_Schemas_PG(server_internal name)
RETURNS TABLE(remote_schema name)
AS $$
DECLARE
-- Import schemata from the information schema
--
-- "The view schemata contains all schemas in the current database
-- that the current user has access to (by way of being the owner
-- or having some privilege)."
-- See https://www.postgresql.org/docs/11/infoschema-schemata.html
--
-- "The information schema is defined in the SQL standard and can
-- therefore be expected to be portable and remain stable"
-- See https://www.postgresql.org/docs/11/information-schema.html
inf_schema name := 'information_schema';
remote_table name := 'schemata';
local_schema name := @extschema@.__CDB_FS_Create_Schema(server_internal, inf_schema);
role_name name := @extschema@.__CDB_FS_Generate_Server_Role_Name(server_internal);
BEGIN
-- Import the foreign schemata table
IF NOT EXISTS (
SELECT * FROM pg_class
WHERE relnamespace = (SELECT oid FROM pg_namespace WHERE nspname = local_schema)
AND relname = remote_table
) THEN
EXECUTE format('IMPORT FOREIGN SCHEMA %I LIMIT TO (%I) FROM SERVER %I INTO %I',
inf_schema, remote_table, server_internal, local_schema);
END IF;
-- Return the result we're interested in. Exclude toast and temp schemas
BEGIN
RETURN QUERY EXECUTE format('
SELECT schema_name::name AS remote_schema FROM %I.%I
WHERE schema_name NOT LIKE %s
ORDER BY remote_schema
', local_schema, remote_table, '''pg_%''');
EXCEPTION WHEN OTHERS THEN
RAISE EXCEPTION 'Not enough permissions to access the server "%"',
@extschema@.__CDB_FS_Extract_Server_Name(server_internal);
END;
END
$$
LANGUAGE PLPGSQL VOLATILE PARALLEL UNSAFE;
--
-- List the names of the tables in a remote PG schema
--
CREATE OR REPLACE FUNCTION @extschema@.__CDB_FS_List_Foreign_Tables_PG(server_internal name, remote_schema name)
RETURNS TABLE(remote_table name)
AS $func$
DECLARE
-- Import `tables` from the information schema
--
-- "The view tables contains all tables and views defined in the
-- current database. Only those tables and views are shown that
-- the current user has access to (by way of being the owner or
-- having some privilege)."
-- https://www.postgresql.org/docs/11/infoschema-tables.html
-- Create local target schema if it does not exists
inf_schema name := 'information_schema';
remote_table name := 'tables';
local_schema name := @extschema@.__CDB_FS_Create_Schema(server_internal, inf_schema);
BEGIN
-- Import the foreign `tables` if not done
IF NOT EXISTS (
SELECT * FROM pg_class
WHERE relnamespace = (SELECT oid FROM pg_namespace WHERE nspname = local_schema)
AND relname = remote_table
) THEN
EXECUTE format('IMPORT FOREIGN SCHEMA %I LIMIT TO (%I) FROM SERVER %I INTO %I',
inf_schema, remote_table, server_internal, local_schema);
END IF;
-- Note: in this context, schema names are not to be quoted
RETURN QUERY EXECUTE format($q$
SELECT table_name::name AS remote_table FROM %I.%I WHERE table_schema = '%s' ORDER BY table_name
$q$, local_schema, remote_table, remote_schema);
END
$func$
LANGUAGE PLPGSQL VOLATILE PARALLEL UNSAFE;
--
-- List the columns in a remote PG schema
--
CREATE OR REPLACE FUNCTION @extschema@.__CDB_FS_List_Foreign_Columns_PG(server_internal name, remote_schema name)
RETURNS TABLE(table_name name, column_name name, column_type text)
AS $func$
DECLARE
-- Import `columns` from the information schema
--
-- "The view columns contains information about all table columns (or view columns)
-- in the database. System columns (oid, etc.) are not included. Only those columns
-- are shown that the current user has access to (by way of being the owner or having some privilege)."
-- https://www.postgresql.org/docs/11/infoschema-columns.html
-- Create local target schema if it does not exists
inf_schema name := 'information_schema';
remote_col_table name := 'columns';
local_schema name := @extschema@.__CDB_FS_Create_Schema(server_internal, inf_schema);
BEGIN
-- Import the foreign `columns` if not done
IF NOT EXISTS (
SELECT * FROM pg_class
WHERE relnamespace = (SELECT oid FROM pg_namespace WHERE nspname = local_schema)
AND relname = remote_col_table
) THEN
EXECUTE format('IMPORT FOREIGN SCHEMA %I LIMIT TO (%I) FROM SERVER %I INTO %I',
inf_schema, remote_col_table, server_internal, local_schema);
END IF;
-- Note: in this context, schema names are not to be quoted
-- We join with the geometry columns to change the type `USER-DEFINED`
-- by its appropiate geometry and srid
RETURN QUERY EXECUTE format($q$
SELECT
a.table_name::name,
a.column_name::name,
COALESCE(b.column_type, a.data_type)::TEXT as column_type
FROM
%I.%I a
LEFT JOIN
@extschema@.__CDB_FS_List_Foreign_Geometry_Columns_PG('%s', '%s') b
ON a.table_name = b.table_name AND a.column_name = b.column_name
WHERE table_schema = '%s'
ORDER BY a.table_name, a.column_name $q$,
local_schema, remote_col_table,
server_internal, remote_schema,
remote_schema);
END
$func$
LANGUAGE PLPGSQL VOLATILE PARALLEL UNSAFE;
--
-- List the geometry columns in a remote PG schema
--
CREATE OR REPLACE FUNCTION @extschema@.__CDB_FS_List_Foreign_Geometry_Columns_PG(server_internal name, remote_schema name, postgis_schema name DEFAULT 'public')
RETURNS TABLE(table_name name, column_name name, column_type text)
AS $func$
DECLARE
-- Import `geometry_columns` and `geography_columns` from the postgis schema
-- We assume that postgis is installed in the public schema
-- Create local target schema if it does not exists
remote_geometry_view name := 'geometry_columns';
remote_geography_view name := 'geography_columns';
local_schema name := @extschema@.__CDB_FS_Create_Schema(server_internal, postgis_schema);
BEGIN
-- Import the foreign `geometry_columns` and `geography_columns` if not done
IF NOT EXISTS (
SELECT * FROM pg_class
WHERE relnamespace = (SELECT oid FROM pg_namespace WHERE nspname = local_schema)
AND relname = remote_geometry_view
) THEN
EXECUTE format('IMPORT FOREIGN SCHEMA %I LIMIT TO (%I, %I) FROM SERVER %I INTO %I',
postgis_schema, remote_geometry_view, remote_geography_view, server_internal, local_schema);
END IF;
BEGIN
-- Note: We return both the type and srid as the type
RETURN QUERY EXECUTE format($q$
SELECT
f_table_name::NAME as table_name,
f_geometry_column::NAME as column_name,
type::TEXT || ',' || srid::TEXT as column_type
FROM
(
SELECT * FROM %I.%I UNION ALL SELECT * FROM %I.%I
) _geo_views
WHERE f_table_schema = '%s'
$q$,
local_schema, remote_geometry_view,
local_schema, remote_geography_view,
remote_schema);
EXCEPTION WHEN OTHERS THEN
RAISE INFO 'Could not find Postgis installation in the remote "%" schema in server "%"',
postgis_schema, @extschema@.__CDB_FS_Extract_Server_Name(server_internal);
RETURN;
END;
END
$func$
LANGUAGE PLPGSQL VOLATILE PARALLEL UNSAFE;
--------------------------------------------------------------------------------
-- Public functions
--------------------------------------------------------------------------------
--
-- List remote schemas in a federated server that the current user has access to.
--
CREATE OR REPLACE FUNCTION @extschema@.CDB_Federated_Server_List_Remote_Schemas(server TEXT)
RETURNS TABLE(remote_schema name)
AS $$
DECLARE
server_internal name := @extschema@.__CDB_FS_Generate_Server_Name(input_name => server, check_existence => true);
server_type name := @extschema@.__CDB_FS_server_type(server_internal);
BEGIN
CASE server_type
WHEN 'postgres_fdw' THEN
RETURN QUERY SELECT @extschema@.__CDB_FS_List_Foreign_Schemas_PG(server_internal);
ELSE
RAISE EXCEPTION 'Not implemented server type % for remote server %', server_type, server;
END CASE;
END
$$
LANGUAGE PLPGSQL VOLATILE PARALLEL UNSAFE;
--
-- List remote tables in a federated server that the current user has access to.
-- For registered tables it returns also the associated configuration
--
CREATE OR REPLACE FUNCTION @extschema@.CDB_Federated_Server_List_Remote_Tables(server TEXT, remote_schema TEXT)
RETURNS TABLE(
registered boolean,
remote_table TEXT,
local_qualified_name TEXT,
id_column_name TEXT,
geom_column_name TEXT,
webmercator_column_name TEXT,
columns JSON
)
AS $$
DECLARE
server_internal name := @extschema@.__CDB_FS_Generate_Server_Name(input_name => server, check_existence => true);
server_type name := @extschema@.__CDB_FS_server_type(server_internal);
BEGIN
CASE server_type
WHEN 'postgres_fdw' THEN
RETURN QUERY
SELECT
coalesce(registered_tables.registered, false)::boolean as registered,
foreign_tables.remote_table::text as remote_table,
registered_tables.local_qualified_name as local_qualified_name,
registered_tables.id_column_name as id_column_name,
registered_tables.geom_column_name as geom_column_name,
registered_tables.webmercator_column_name as webmercator_column_name,
remote_columns.columns as columns
FROM
@extschema@.__CDB_FS_List_Foreign_Tables_PG(server_internal, remote_schema) foreign_tables
LEFT JOIN
@extschema@.__CDB_FS_List_Registered_Tables(server_internal, remote_schema) registered_tables
ON foreign_tables.remote_table = registered_tables.remote_table
LEFT JOIN
( -- Extract and group columns with their remote table
SELECT table_name,
json_agg(json_build_object('Name', column_name, 'Type', column_type)) as columns
FROM @extschema@.__CDB_FS_List_Foreign_Columns_PG(server_internal, remote_schema)
GROUP BY table_name
) remote_columns
ON foreign_tables.remote_table = remote_columns.table_name
ORDER BY foreign_tables.remote_table;
ELSE
RAISE EXCEPTION 'Not implemented server type % for remote server %', server_type, remote_server;
END CASE;
END
$$
LANGUAGE PLPGSQL VOLATILE PARALLEL UNSAFE;
--
-- List the columns of a remote table in a federated server that the current user has access to.
--
CREATE OR REPLACE FUNCTION @extschema@.CDB_Federated_Server_List_Remote_Columns(
server TEXT,
remote_schema TEXT,
remote_table TEXT)
RETURNS TABLE(column_n name, column_t text)
AS $$
DECLARE
server_internal name := @extschema@.__CDB_FS_Generate_Server_Name(input_name => server, check_existence => true);
server_type name := @extschema@.__CDB_FS_server_type(server_internal);
BEGIN
IF remote_table IS NULL THEN
RAISE EXCEPTION 'Remote table name cannot be NULL';
END IF;
CASE server_type
WHEN 'postgres_fdw' THEN
RETURN QUERY
SELECT
column_name,
column_type
FROM @extschema@.__CDB_FS_List_Foreign_Columns_PG(server_internal, remote_schema)
WHERE table_name = remote_table
ORDER BY column_name;
ELSE
RAISE EXCEPTION 'Not implemented server type % for remote server %', server_type, remote_server;
END CASE;
END
$$
LANGUAGE PLPGSQL VOLATILE PARALLEL UNSAFE;