cartodb-postgresql/scripts-available/CDB_FederatedServerListRemote.sql
2019-10-31 15:29:37 +01:00

188 lines
7.4 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 $$
DECLARE
-- Import schemata from the information schema
--
-- "The view schemata contains all schemas in the current database
-- that the current user has access to (by way of being the owner
-- or having some privilege)."
-- See https://www.postgresql.org/docs/11/infoschema-schemata.html
--
-- "The information schema is defined in the SQL standard and can
-- therefore be expected to be portable and remain stable"
-- See https://www.postgresql.org/docs/11/information-schema.html
inf_schema name := 'information_schema';
remote_table name := 'schemata';
local_schema name := @extschema@.__CDB_FS_Create_Schema(server_internal, inf_schema);
role_name text := @extschema@.__CDB_FS_Generate_Server_Role_Name(server_internal);
BEGIN
-- Import the foreign schemata table
IF NOT EXISTS (
SELECT * FROM pg_class
WHERE relnamespace = (SELECT oid FROM pg_namespace WHERE nspname = local_schema)
AND relname = remote_table
) THEN
EXECUTE format('IMPORT FOREIGN SCHEMA %I LIMIT TO (%I) FROM SERVER %I INTO %I', inf_schema, remote_table, server_internal, local_schema);
END IF;
-- Return the result we're interested in. Exclude toast and temp schemas
RETURN QUERY EXECUTE format('
SELECT schema_name::name AS remote_schema FROM %I.%I
WHERE schema_name NOT LIKE %s
ORDER BY remote_schema
', local_schema, remote_table, '''pg_%''');
END
$$
LANGUAGE PLPGSQL VOLATILE PARALLEL UNSAFE;
--
-- List the tables from 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;
-- Return the result we're interested in
-- 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 from a remote PG table
--
CREATE OR REPLACE FUNCTION @extschema@.__CDB_FS_List_Foreign_Columns_PG(server_internal name, remote_schema name, remote_table name)
RETURNS TABLE(column_name name)
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);
sql_q text;
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;
-- Return the result we're interested in
-- Note: in this context, remote schema and remote table names are not to be quoted
RETURN QUERY EXECUTE format($q$
SELECT column_name::name FROM %I.%I
WHERE table_schema = '%s' AND table_name = '%s'
ORDER BY column_name$q$,
local_schema, remote_col_table, remote_schema, remote_table);
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.
--
CREATE OR REPLACE FUNCTION @extschema@.CDB_Federated_Server_List_Remote_Tables(server TEXT, remote_schema TEXT)
RETURNS TABLE(remote_table name)
AS $$
DECLARE
server_internal name := @extschema@.__CDB_FS_Generate_Server_Name(input_name := server, check_existence := true);
server_type name := @extschema@.__CDB_FS_server_type(server_internal);
BEGIN
CASE server_type
WHEN 'postgres_fdw' THEN
RETURN QUERY SELECT @extschema@.__CDB_FS_List_Foreign_Tables_PG(server_internal, remote_schema);
ELSE
RAISE EXCEPTION 'Not implemented server type % for remote server %', server_type, remote_server;
END CASE;
END
$$
LANGUAGE PLPGSQL VOLATILE PARALLEL UNSAFE;
CREATE OR REPLACE FUNCTION @extschema@.CDB_Federated_Server_List_Remote_Columns(
server TEXT,
remote_schema TEXT,
remote_table TEXT)
RETURNS TABLE(column_name name)
AS $$
DECLARE
server_internal name := @extschema@.__CDB_FS_Generate_Server_Name(input_name := server, check_existence := true);
server_type name := @extschema@.__CDB_FS_server_type(server_internal);
BEGIN
CASE server_type
WHEN 'postgres_fdw' THEN
RETURN QUERY SELECT @extschema@.__CDB_FS_List_Foreign_Columns_PG(server_internal, remote_schema, remote_table);
ELSE
RAISE EXCEPTION 'Not implemented server type % for remote server %', server_type, remote_server;
END CASE;
END
$$
LANGUAGE PLPGSQL VOLATILE PARALLEL UNSAFE;