> What is a reliable way to programmatically &
generically populate an empty schema with all the objects in the public
schema as a template?
The simplest way is just to load the attached clone_schema function. It was originally created by Emanuel '3manuek', which I enhanced. It
now copies all sequences, tables, indexes, rules, triggers, data(optional), views & functions from any existing schema to a new schema.
Then just call the function.
SAMPLE CALL:
SELECT clone_schema('public', 'new_schema', TRUE);
Use FALSE if you do not want to copy data.
--
The simplest way is just to load the attached clone_schema function. It was originally created by Emanuel '3manuek', which I enhanced. It
now copies all sequences, tables, indexes, rules, triggers, data(optional), views & functions from any existing schema to a new schema.
Then just call the function.
SAMPLE CALL:
SELECT clone_schema('public', 'new_schema', TRUE);
Use FALSE if you do not want to copy data.
--
Melvin Davidson
Maj. Database & Exploration Specialist
Universe Exploration Command – UXC
Employment by invitation only!
Maj. Database & Exploration Specialist
Universe Exploration Command – UXC
Employment by invitation only!
-- Function: public.clone_schema(text, text, boolean)
-- DROP FUNCTION public.clone_schema(text, text, boolean);
CREATE OR REPLACE FUNCTION public.clone_schema(
source_schema text,
dest_schema text,
include_recs boolean)
RETURNS void AS
$BODY$
-- Initial code by Emanuel '3manuek'
-- Last revision 2017-04-17 by Melvin Davidson
-- Added SELECT REPLACE for schema views
--
-- This function will clone all sequences, tables, indexes, rules, triggers,
-- data(optional), views & functions from any existing schema to a new schema
-- SAMPLE CALL:
-- SELECT clone_schema('public', 'new_schema', TRUE);
DECLARE
src_oid oid;
tbl_oid oid;
func_oid oid;
con_oid oid;
v_path text;
v_func text;
v_args text;
v_conname text;
v_rule text;
v_trig text;
object text;
buffer text;
srctbl text;
default_ text;
v_column text;
qry text;
dest_qry text;
v_def text;
v_stat integer;
seqval bigint;
sq_last_value bigint;
sq_max_value bigint;
sq_start_value bigint;
sq_increment_by bigint;
sq_min_value bigint;
sq_cache_value bigint;
sq_log_cnt bigint;
sq_is_called boolean;
sq_is_cycled boolean;
sq_cycled char(10);
BEGIN
-- Check that source_schema exists
SELECT oid INTO src_oid
FROM pg_namespace
WHERE nspname = quote_ident(source_schema);
IF NOT FOUND
THEN
RAISE NOTICE 'source schema % does not exist!', source_schema;
RETURN ;
END IF;
-- Check that dest_schema does not yet exist
PERFORM nspname
FROM pg_namespace
WHERE nspname = quote_ident(dest_schema);
IF FOUND
THEN
RAISE NOTICE 'dest schema % already exists!', dest_schema;
RETURN ;
END IF;
EXECUTE 'CREATE SCHEMA ' || quote_ident(dest_schema) ;
-- Add schema comment
SELECT description INTO v_def
FROM pg_description
WHERE objoid = src_oid
AND objsubid = 0;
IF FOUND
THEN
EXECUTE 'COMMENT ON SCHEMA ' || quote_ident(dest_schema) || ' IS ' || quote_literal(v_def);
END IF;
-- Create sequences
-- TODO: Find a way to make this sequence's owner is the correct table.
FOR object IN
SELECT sequence_name::text
FROM information_schema.sequences
WHERE sequence_schema = quote_ident(source_schema)
LOOP
EXECUTE 'CREATE SEQUENCE ' || quote_ident(dest_schema) || '.' || quote_ident(object);
srctbl := quote_ident(source_schema) || '.' || quote_ident(object);
EXECUTE 'SELECT last_value, max_value, start_value, increment_by, min_value, cache_value, log_cnt, is_cycled, is_called
FROM ' || quote_ident(source_schema) || '.' || quote_ident(object) || ';'
INTO sq_last_value, sq_max_value, sq_start_value, sq_increment_by, sq_min_value, sq_cache_value, sq_log_cnt, sq_is_cycled, sq_is_called ;
IF sq_is_cycled
THEN
sq_cycled := 'CYCLE';
ELSE
sq_cycled := 'NO CYCLE';
END IF;
EXECUTE 'ALTER SEQUENCE ' || quote_ident(dest_schema) || '.' || quote_ident(object)
|| ' INCREMENT BY ' || sq_increment_by
|| ' MINVALUE ' || sq_min_value
|| ' MAXVALUE ' || sq_max_value
|| ' START WITH ' || sq_start_value
|| ' RESTART ' || sq_min_value
|| ' CACHE ' || sq_cache_value
|| sq_cycled || ' ;' ;
buffer := quote_ident(dest_schema) || '.' || quote_ident(object);
IF include_recs
THEN
EXECUTE 'SELECT setval( ''' || buffer || ''', ' || sq_last_value || ', ' || sq_is_called || ');' ;
ELSE
EXECUTE 'SELECT setval( ''' || buffer || ''', ' || sq_start_value || ', ' || sq_is_called || ');' ;
END IF;
-- add sequence comments
SELECT oid INTO tbl_oid
FROM pg_class
WHERE relkind = 'S'
AND relnamespace = src_oid
AND relname = quote_ident(object);
SELECT description INTO v_def
FROM pg_description
WHERE objoid = tbl_oid
AND objsubid = 0;
IF FOUND
THEN
EXECUTE 'COMMENT ON SEQUENCE ' || quote_ident(dest_schema) || '.' || quote_ident(object)
|| ' IS ''' || v_def || ''';';
END IF;
END LOOP;
-- Create tables
FOR object IN
SELECT TABLE_NAME::text
FROM information_schema.tables
WHERE table_schema = quote_ident(source_schema)
AND table_type = 'BASE TABLE'
LOOP
buffer := quote_ident(dest_schema) || '.' || quote_ident(object);
EXECUTE 'CREATE TABLE ' || buffer || ' (LIKE ' || quote_ident(source_schema) || '.' || quote_ident(object)
|| ' INCLUDING ALL)';
-- Add table comment
SELECT oid INTO tbl_oid
FROM pg_class
WHERE relkind = 'r'
AND relnamespace = src_oid
AND relname = quote_ident(object);
SELECT description INTO v_def
FROM pg_description
WHERE objoid = tbl_oid
AND objsubid = 0;
IF FOUND
THEN
EXECUTE 'COMMENT ON TABLE ' || quote_ident(dest_schema) || '.' || quote_ident(object)
|| ' IS ''' || v_def || ''';';
END IF;
IF include_recs
THEN
-- Insert records from source table
EXECUTE 'INSERT INTO ' || buffer || ' SELECT * FROM ' || quote_ident(source_schema) || '.' || quote_ident(object) || ';';
END IF;
FOR v_column, default_ IN
SELECT column_name::text,
REPLACE(column_default::text, quote_ident(source_schema) || '.', quote_ident(dest_schema) || '.' )
FROM information_schema.COLUMNS
WHERE table_schema = dest_schema
AND TABLE_NAME = object
AND column_default LIKE 'nextval(%' || quote_ident(source_schema) || '%::regclass)'
LOOP
EXECUTE 'ALTER TABLE ' || buffer || ' ALTER COLUMN ' || v_column || ' SET DEFAULT ' || default_;
END LOOP;
END LOOP;
-- set column statistics
FOR tbl_oid, srctbl IN
SELECT oid, relname
FROM pg_class
WHERE relnamespace = src_oid
AND relkind = 'r'
LOOP
FOR v_column, v_stat IN
SELECT attname, attstattarget
FROM pg_attribute
WHERE attrelid = tbl_oid
AND attnum > 0
LOOP
buffer := quote_ident(dest_schema) || '.' || quote_ident(srctbl);
-- RAISE EXCEPTION 'ALTER TABLE % ALTER COLUMN % SET STATISTICS %', buffer, v_column, v_stat::text;
EXECUTE 'ALTER TABLE ' || buffer || ' ALTER COLUMN ' || quote_ident(v_column) || ' SET STATISTICS ' || v_stat || ';';
END LOOP;
END LOOP;
-- add FK constraint
FOR qry IN
SELECT 'ALTER TABLE ' || quote_ident(dest_schema) || '.' || quote_ident(rn.relname)
|| ' ADD CONSTRAINT ' || quote_ident(ct.conname) || ' ' || replace(pg_get_constraintdef(ct.oid), quote_ident(source_schema) || '.', quote_ident(dest_schema) || '.') || ';'
FROM pg_constraint ct
JOIN pg_class rn ON rn.oid = ct.conrelid
WHERE connamespace = src_oid
AND rn.relkind = 'r'
AND ct.contype = 'f'
LOOP
EXECUTE qry;
END LOOP;
-- Add constraint comment
FOR con_oid IN
SELECT oid
FROM pg_constraint
WHERE conrelid = tbl_oid
LOOP
SELECT conname INTO v_conname
FROM pg_constraint
WHERE oid = con_oid;
SELECT description INTO v_def
FROM pg_description
WHERE objoid = con_oid;
IF FOUND
THEN
EXECUTE 'COMMENT ON CONSTRAINT ' || v_conname || ' ON ' || quote_ident(dest_schema) || '.' || quote_ident(object)
|| ' IS ''' || v_def || ''';';
END IF;
END LOOP;
-- Create views
FOR object IN
SELECT table_name::text,
view_definition
FROM information_schema.views
WHERE table_schema = quote_ident(source_schema)
LOOP
buffer := quote_ident(dest_schema) || '.' || quote_ident(object);
SELECT view_definition INTO v_def
FROM information_schema.views
WHERE table_schema = quote_ident(source_schema)
AND table_name = quote_ident(object);
SELECT REPLACE(v_def, source_schema, dest_schema) INTO v_def;
-- RAISE NOTICE 'view def, % , source % , dest % ', v_def, source_schema, dest_schema;
EXECUTE 'CREATE OR REPLACE VIEW ' || buffer || ' AS ' || v_def || ';' ;
-- Add comment
SELECT oid INTO tbl_oid
FROM pg_class
WHERE relkind = 'v'
AND relnamespace = src_oid
AND relname = quote_ident(object);
SELECT description INTO v_def
FROM pg_description
WHERE objoid = tbl_oid
AND objsubid = 0;
IF FOUND
THEN
EXECUTE 'COMMENT ON VIEW ' || quote_ident(dest_schema) || '.' || quote_ident(object)
|| ' IS ' || quote_literal(v_def);
END IF;
END LOOP;
-- Create functions
FOR func_oid IN
SELECT oid, proargnames
FROM pg_proc
WHERE pronamespace = src_oid
LOOP
SELECT pg_get_functiondef(func_oid) INTO qry;
SELECT proname, oidvectortypes(proargtypes) INTO v_func, v_args
FROM pg_proc
WHERE oid = func_oid;
SELECT replace(qry, quote_ident(source_schema) || '.', quote_ident(dest_schema) || '.') INTO dest_qry;
EXECUTE dest_qry;
-- Add function comment
SELECT description INTO v_def
FROM pg_description
WHERE objoid = func_oid
AND objsubid = 0;
IF FOUND
THEN
-- RAISE NOTICE 'func_oid %, object %, v_args %', func_oid::text, quote_ident(object), v_args;
EXECUTE 'COMMENT ON FUNCTION ' || quote_ident(dest_schema) || '.' || quote_ident(v_func) || '(' || v_args || ')'
|| ' IS ' || quote_literal(v_def) ||';' ;
END IF;
END LOOP;
-- add Rules
FOR v_def IN
SELECT definition
FROM pg_rules
WHERE schemaname = quote_ident(source_schema)
LOOP
IF v_def IS NOT NULL
THEN
SELECT replace(v_def, 'TO ', 'TO ' || quote_ident(dest_schema) || '.') INTO v_def;
EXECUTE ' ' || v_def;
END IF;
END LOOP;
-- add triggers
FOR v_def IN
SELECT pg_get_triggerdef(oid)
FROM pg_trigger
WHERE tgname NOT LIKE 'RI_%'
AND tgrelid IN (SELECT oid
FROM pg_class
WHERE relkind = 'r'
AND relnamespace = src_oid)
LOOP
SELECT replace(v_def, ' ON ', ' ON ' || quote_ident(dest_schema) || '.') INTO dest_qry;
EXECUTE dest_qry;
END LOOP;
-- Disable inactive triggers
-- D = disabled
FOR tbl_oid IN
SELECT oid
FROM pg_trigger
WHERE tgenabled = 'D'
AND tgname NOT LIKE 'RI_%'
AND tgrelid IN (SELECT oid
FROM pg_class
WHERE relkind = 'r'
AND relnamespace = src_oid)
LOOP
SELECT t.tgname, c.relname INTO object, srctbl
FROM pg_trigger t
JOIN pg_class c ON c.oid = t.tgrelid
WHERE t.oid = tbl_oid;
IF FOUND
THEN
EXECUTE 'ALTER TABLE ' || dest_schema || '.' || srctbl || ' DISABLE TRIGGER ' || object || ';';
END IF;
END LOOP;
-- Add index comment
FOR tbl_oid IN
SELECT oid
FROM pg_class
WHERE relkind = 'i'
AND relnamespace = src_oid
LOOP
SELECT relname INTO object
FROM pg_class
WHERE oid = tbl_oid;
SELECT description INTO v_def
FROM pg_description
WHERE objoid = tbl_oid
AND objsubid = 0;
IF FOUND
THEN
EXECUTE 'COMMENT ON INDEX ' || quote_ident(dest_schema) || '.' || quote_ident(object)
|| ' IS ''' || v_def || ''';';
END IF;
END LOOP;
-- add rule comments
FOR con_oid IN
SELECT oid, *
FROM pg_rewrite
WHERE rulename <> '_RETURN'::name
LOOP
SELECT rulename, ev_class INTO v_rule, tbl_oid
FROM pg_rewrite
WHERE oid = con_oid;
SELECT relname INTO object
FROM pg_class
WHERE oid = tbl_oid
AND relkind = 'r';
SELECT description INTO v_def
FROM pg_description
WHERE objoid = con_oid
AND objsubid = 0;
IF FOUND
THEN
EXECUTE 'COMMENT ON RULE ' || v_rule || ' ON ' || quote_ident(dest_schema) || '.' || object || ' IS ' || quote_literal(v_def);
END IF;
END LOOP;
-- add trigger comments
FOR con_oid IN
SELECT oid, *
FROM pg_trigger
WHERE tgname NOT LIKE 'RI_%'
LOOP
SELECT tgname, tgrelid INTO v_trig, tbl_oid
FROM pg_trigger
WHERE oid = con_oid;
SELECT relname INTO object
FROM pg_class
WHERE oid = tbl_oid
AND relkind = 'r';
SELECT description INTO v_def
FROM pg_description
WHERE objoid = con_oid
AND objsubid = 0;
IF FOUND
THEN
EXECUTE 'COMMENT ON TRIGGER ' || v_trig || ' ON ' || quote_ident(dest_schema) || '.' || object || ' IS ' || quote_literal(v_def);
END IF;
END LOOP;
RETURN;
END;
$BODY$
LANGUAGE plpgsql VOLATILE
COST 100;
ALTER FUNCTION public.clone_schema(text, text, boolean)
OWNER TO postgres;
COMMENT ON FUNCTION public.clone_schema(text, text, boolean) IS 'Duplicates sequences, tables, indexes, rules, triggers, data(optional),
views & functions from the source schema to the destination schema';
