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feat(db-tool): hectic-inheritance: add hectic.immutable + diff coverage

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Add a hectic.immutable parent table. Tables inheriting it get auto-attached
BEFORE INSERT/UPDATE/DELETE/TRUNCATE row+statement triggers that block DML
unless the session sets hectic.migration_mode='on' (intended use: SET LOCAL
inside a migration transaction). Same exemptions as the rest of the bundle
apply (hectic schema, partitions, temp tables, GUC-excluded schemas).

database diff now appends an --- IMMUTABLE TABLE DATA --- section to its
output, with per-table unified row diffs of every table inheriting
hectic.immutable, surfacing drift in 'frozen' reference data alongside schema
drift. Subcommand exits non-zero when either schema or data differs.

Test postgres-init-hectic-inheritance extended to 10 cases covering
immutable triggers, DML blocked outside migration_mode, SET LOCAL allowing
DML inside a transaction, GUC not leaking past COMMIT, and TRUNCATE under
migration_mode.
This commit is contained in:
yukkop
2026-04-30 16:10:38 +00:00
parent 31d2994997
commit 2eaa568f5b
4 changed files with 266 additions and 5 deletions
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104
package/db-tool/sql/hectic-inheritance.sql
View File

@@ -1,17 +1,28 @@
-- hectic.created_at / hectic.updated_at inheritance machinery.
-- hectic.created_at / hectic.updated_at / hectic.immutable inheritance machinery.
--
-- Provides:
-- * schema hectic
-- * tables hectic.created_at(created_at TIMESTAMPTZ NOT NULL DEFAULT NOW())
-- hectic.updated_at(updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW())
-- hectic.immutable() -- pure marker
-- * function hectic.set_updated_at() -- BEFORE UPDATE row trigger function
-- * function hectic.block_immutable_dml()
-- BEFORE INSERT/UPDATE/DELETE/TRUNCATE row+statement trigger function;
-- allows DML iff current_setting('hectic.migration_mode', true) = 'on'.
-- * GUC hectic.inheritance_extra_excluded_schemas
-- (text, comma-separated list of schemas the enforcement trigger skips)
-- * GUC hectic.migration_mode
-- (text, 'on' enables DML on tables inheriting hectic.immutable.
-- Intended use: SET LOCAL inside a migration transaction.)
-- * event trigger hectic_enforce_created_at_inheritance
-- RAISE EXCEPTION on CREATE TABLE that does not inherit hectic.created_at
-- * event trigger hectic_attach_updated_at_trigger
-- auto-attaches BEFORE UPDATE row trigger calling hectic.set_updated_at()
-- on any new table that inherits hectic.updated_at and lacks one.
-- * event trigger hectic_attach_immutable_triggers
-- auto-attaches BEFORE INSERT/UPDATE/DELETE FOR EACH ROW and BEFORE
-- TRUNCATE FOR EACH STATEMENT triggers calling hectic.block_immutable_dml()
-- on any new table that inherits hectic.immutable and lacks them.
--
-- Idempotent: safe to run on an already-bootstrapped database.
@@ -25,6 +36,8 @@ CREATE TABLE IF NOT EXISTS "hectic"."updated_at" (
"updated_at" TIMESTAMPTZ NOT NULL DEFAULT NOW()
);
CREATE TABLE IF NOT EXISTS "hectic"."immutable" ();
DO $bootstrap$
BEGIN
PERFORM set_config('hectic.inheritance_extra_excluded_schemas',
@@ -35,6 +48,16 @@ EXCEPTION WHEN undefined_object THEN
END
$bootstrap$;
DO $bootstrap_mm$
BEGIN
PERFORM set_config('hectic.migration_mode',
current_setting('hectic.migration_mode', true),
false);
EXCEPTION WHEN undefined_object THEN
PERFORM set_config('hectic.migration_mode', '', false);
END
$bootstrap_mm$;
CREATE OR REPLACE FUNCTION "hectic"."set_updated_at"() RETURNS trigger
LANGUAGE plpgsql AS $fn$
BEGIN
@@ -43,6 +66,29 @@ BEGIN
END
$fn$;
CREATE OR REPLACE FUNCTION "hectic"."block_immutable_dml"() RETURNS trigger
LANGUAGE plpgsql AS $fn$
DECLARE
mm text;
BEGIN
BEGIN
mm := current_setting('hectic.migration_mode', true);
EXCEPTION WHEN OTHERS THEN
mm := '';
END;
IF mm = 'on' THEN
IF TG_LEVEL = 'STATEMENT' THEN RETURN NULL; END IF;
IF TG_OP = 'DELETE' THEN RETURN OLD; END IF;
RETURN NEW;
END IF;
RAISE EXCEPTION
'hectic: table %.% inherits hectic.immutable; % blocked outside migration_mode',
quote_ident(TG_TABLE_SCHEMA), quote_ident(TG_TABLE_NAME), TG_OP
USING HINT = 'wrap the statement in a migration transaction with '
|| 'SET LOCAL hectic.migration_mode = ''on''';
END
$fn$;
CREATE OR REPLACE FUNCTION "hectic"."_is_excluded_schema"(p_schema text) RETURNS boolean
LANGUAGE plpgsql STABLE AS $fn$
DECLARE
@@ -153,3 +199,59 @@ CREATE EVENT TRIGGER "hectic_attach_updated_at_trigger"
ON ddl_command_end
WHEN TAG IN ('CREATE TABLE')
EXECUTE FUNCTION "hectic"."attach_updated_at_trigger"();
CREATE OR REPLACE FUNCTION "hectic"."attach_immutable_triggers"() RETURNS event_trigger
LANGUAGE plpgsql AS $fn$
DECLARE
obj record;
rel pg_class;
schema_name text;
parent_oid oid;
has_row boolean;
has_trunc boolean;
BEGIN
parent_oid := 'hectic.immutable'::regclass;
FOR obj IN SELECT * FROM pg_event_trigger_ddl_commands() WHERE command_tag = 'CREATE TABLE'
LOOP
SELECT * INTO rel FROM pg_class WHERE oid = obj.objid;
IF NOT FOUND THEN CONTINUE; END IF;
IF rel.relpersistence = 't' THEN CONTINUE; END IF;
IF rel.relispartition THEN CONTINUE; END IF;
SELECT nspname INTO schema_name FROM pg_namespace WHERE oid = rel.relnamespace;
IF schema_name = 'hectic' THEN CONTINUE; END IF;
IF NOT "hectic"."_table_inherits"(rel.oid, parent_oid) THEN CONTINUE; END IF;
SELECT EXISTS (
SELECT 1 FROM pg_trigger
WHERE tgrelid = rel.oid
AND tgname = 'hectic_block_immutable_dml'
AND NOT tgisinternal
) INTO has_row;
SELECT EXISTS (
SELECT 1 FROM pg_trigger
WHERE tgrelid = rel.oid
AND tgname = 'hectic_block_immutable_truncate'
AND NOT tgisinternal
) INTO has_trunc;
IF NOT has_row THEN
EXECUTE format(
'CREATE TRIGGER %I BEFORE INSERT OR UPDATE OR DELETE ON %I.%I '
|| 'FOR EACH ROW EXECUTE FUNCTION "hectic"."block_immutable_dml"()',
'hectic_block_immutable_dml', schema_name, rel.relname
);
END IF;
IF NOT has_trunc THEN
EXECUTE format(
'CREATE TRIGGER %I BEFORE INSERT OR UPDATE OR DELETE OR TRUNCATE ON %I.%I '
|| 'FOR EACH STATEMENT EXECUTE FUNCTION "hectic"."block_immutable_dml"()',
'hectic_block_immutable_truncate', schema_name, rel.relname
);
END IF;
END LOOP;
END
$fn$;
DROP EVENT TRIGGER IF EXISTS "hectic_attach_immutable_triggers";
CREATE EVENT TRIGGER "hectic_attach_immutable_triggers"
ON ddl_command_end
WHEN TAG IN ('CREATE TABLE')
EXECUTE FUNCTION "hectic"."attach_immutable_triggers"();