Hierarchical Continuous Aggregates

Enable users create Hierarchical Continuous Aggregates (aka Continuous
Aggregates on top of another Continuous Aggregates).

With this PR users can create levels of aggregation granularity in
Continuous Aggregates making the refresh process even faster.

A problem with this feature can be in upper levels we can end up with
the "average of averages". But to get the "real average" we can rely on
"stats_aggs" TimescaleDB Toolkit function that calculate and store the
partials that can be finalized with other toolkit functions like
"average" and "sum".

Closes timescale#1400

sql/pre_install/tables.sql

@@ -203,7 +203,7 @@ CREATE INDEX chunk_compressed_chunk_id_idx ON _timescaledb_catalog.chunk (compre
 --we could use a partial index (where osm_chunk is true). However, the catalog code
 --does not work with partial/functional indexes. So we instead have a full index here.
 --Another option would be to use the status field to identify a OSM chunk. However bit
---operations only work on varbit datatype and not integer datatype. 
+--operations only work on varbit datatype and not integer datatype.
 CREATE INDEX chunk_osm_chunk_idx ON _timescaledb_catalog.chunk (osm_chunk, hypertable_id);
 
 SELECT pg_catalog.pg_extension_config_dump('_timescaledb_catalog.chunk', '');
@@ -350,6 +350,7 @@ SELECT pg_catalog.pg_extension_config_dump('_timescaledb_catalog.metadata', $$
 CREATE TABLE _timescaledb_catalog.continuous_agg (
   mat_hypertable_id integer NOT NULL,
   raw_hypertable_id integer NOT NULL,
+  parent_mat_hypertable_id integer,
   user_view_schema name NOT NULL,
   user_view_name name NOT NULL,
   partial_view_schema name NOT NULL,
@@ -364,7 +365,9 @@ CREATE TABLE _timescaledb_catalog.continuous_agg (
   CONSTRAINT continuous_agg_partial_view_schema_partial_view_name_key UNIQUE (partial_view_schema, partial_view_name),
   CONSTRAINT continuous_agg_user_view_schema_user_view_name_key UNIQUE (user_view_schema, user_view_name),
   CONSTRAINT continuous_agg_mat_hypertable_id_fkey FOREIGN KEY (mat_hypertable_id) REFERENCES _timescaledb_catalog.hypertable (id) ON DELETE CASCADE,
-  CONSTRAINT continuous_agg_raw_hypertable_id_fkey FOREIGN KEY (raw_hypertable_id) REFERENCES _timescaledb_catalog.hypertable (id) ON DELETE CASCADE
+  CONSTRAINT continuous_agg_raw_hypertable_id_fkey FOREIGN KEY (raw_hypertable_id) REFERENCES _timescaledb_catalog.hypertable (id) ON DELETE CASCADE,
+  CONSTRAINT continuous_agg_parent_mat_hypertable_id_fkey FOREIGN KEY (parent_mat_hypertable_id)
+    REFERENCES _timescaledb_catalog.continuous_agg (mat_hypertable_id) ON DELETE CASCADE
 );
 
 CREATE INDEX continuous_agg_raw_hypertable_id_idx ON _timescaledb_catalog.continuous_agg (raw_hypertable_id);
@@ -559,7 +562,7 @@ SELECT pg_catalog.pg_extension_config_dump('_timescaledb_catalog.continuous_agg_
 SELECT pg_catalog.pg_extension_config_dump(pg_get_serial_sequence('_timescaledb_catalog.continuous_agg_migrate_plan_step', 'step_id'), '');
 
 CREATE TABLE _timescaledb_internal.job_errors (
-  job_id integer not null, 
+  job_id integer not null,
   pid integer,
   start_time timestamptz,
   finish_time timestamptz,

sql/updates/latest-dev.sql

@@ -220,17 +220,17 @@ CREATE TABLE _timescaledb_config.bgw_job (
   config jsonb ,
   check_schema NAME,
   check_name NAME,
-  timezone TEXT 
+  timezone TEXT
 );
 
 ALTER SEQUENCE _timescaledb_config.bgw_job_id_seq OWNED BY _timescaledb_config.bgw_job.id;
 CREATE INDEX bgw_job_proc_hypertable_id_idx ON _timescaledb_config.bgw_job(proc_schema,proc_name,hypertable_id);
 
 INSERT INTO _timescaledb_config.bgw_job(
-    id, application_name, schedule_interval, 
-    max_runtime, max_retries, retry_period, 
-    proc_schema, proc_name, owner, scheduled, 
-    hypertable_id, config, check_schema, check_name, 
+    id, application_name, schedule_interval,
+    max_runtime, max_retries, retry_period,
+    proc_schema, proc_name, owner, scheduled,
+    hypertable_id, config, check_schema, check_name,
     fixed_schedule
 )
 SELECT id, application_name, schedule_interval, max_runtime, max_retries, retry_period,
@@ -247,19 +247,19 @@ GRANT SELECT ON _timescaledb_config.bgw_job_id_seq TO PUBLIC;
 
 -- do simple CREATE for the functions with modified signatures
 CREATE FUNCTION @extschema@.add_continuous_aggregate_policy(
-continuous_aggregate REGCLASS, start_offset "any", 
-end_offset "any", schedule_interval INTERVAL, 
-if_not_exists BOOL = false, 
+continuous_aggregate REGCLASS, start_offset "any",
+end_offset "any", schedule_interval INTERVAL,
+if_not_exists BOOL = false,
 initial_start TIMESTAMPTZ = NULL,
 timezone TEXT = NULL)
 RETURNS INTEGER
 AS '@MODULE_PATHNAME@', 'ts_policy_refresh_cagg_add'
 LANGUAGE C VOLATILE;
 
 CREATE FUNCTION @extschema@.add_compression_policy(
-        hypertable REGCLASS, compress_after "any", 
+        hypertable REGCLASS, compress_after "any",
         if_not_exists BOOL = false,
-        schedule_interval INTERVAL = NULL, 
+        schedule_interval INTERVAL = NULL,
         initial_start TIMESTAMPTZ = NULL,
         timezone TEXT = NULL
 )
@@ -399,3 +399,100 @@ BEGIN
      RAISE EXCEPTION 'unable to modify frozen chunk %s', TG_TABLE_NAME;
 END;
 $BODY$ SET search_path TO pg_catalog, pg_temp;
+
+--
+-- Rebuild the catalog table `_timescaledb_catalog.continuous_agg`
+--
+DROP VIEW IF EXISTS timescaledb_information.hypertables;
+DROP VIEW IF EXISTS timescaledb_information.continuous_aggregates;
+DROP PROCEDURE IF EXISTS @extschema@.cagg_migrate (REGCLASS, BOOLEAN, BOOLEAN);
+DROP FUNCTION IF EXISTS _timescaledb_internal.cagg_migrate_pre_validation (TEXT, TEXT, TEXT);
+DROP PROCEDURE IF EXISTS _timescaledb_internal.cagg_migrate_create_plan (_timescaledb_catalog.continuous_agg, TEXT, BOOLEAN, BOOLEAN);
+DROP FUNCTION IF EXISTS _timescaledb_internal.cagg_migrate_plan_exists (INTEGER);
+DROP PROCEDURE IF EXISTS _timescaledb_internal.cagg_migrate_execute_plan (_timescaledb_catalog.continuous_agg);
+DROP PROCEDURE IF EXISTS _timescaledb_internal.cagg_migrate_execute_create_new_cagg (_timescaledb_catalog.continuous_agg, _timescaledb_catalog.continuous_agg_migrate_plan_step);
+DROP PROCEDURE IF EXISTS _timescaledb_internal.cagg_migrate_execute_disable_policies (_timescaledb_catalog.continuous_agg, _timescaledb_catalog.continuous_agg_migrate_plan_step);
+DROP PROCEDURE IF EXISTS _timescaledb_internal.cagg_migrate_execute_enable_policies (_timescaledb_catalog.continuous_agg, _timescaledb_catalog.continuous_agg_migrate_plan_step);
+DROP PROCEDURE IF EXISTS _timescaledb_internal.cagg_migrate_execute_copy_policies (_timescaledb_catalog.continuous_agg, _timescaledb_catalog.continuous_agg_migrate_plan_step);
+DROP PROCEDURE IF EXISTS _timescaledb_internal.cagg_migrate_execute_refresh_new_cagg (_timescaledb_catalog.continuous_agg, _timescaledb_catalog.continuous_agg_migrate_plan_step);
+DROP PROCEDURE IF EXISTS _timescaledb_internal.cagg_migrate_execute_copy_data (_timescaledb_catalog.continuous_agg, _timescaledb_catalog.continuous_agg_migrate_plan_step);
+DROP PROCEDURE IF EXISTS _timescaledb_internal.cagg_migrate_execute_override_cagg (_timescaledb_catalog.continuous_agg, _timescaledb_catalog.continuous_agg_migrate_plan_step);
+DROP PROCEDURE IF EXISTS _timescaledb_internal.cagg_migrate_execute_drop_old_cagg (_timescaledb_catalog.continuous_agg, _timescaledb_catalog.continuous_agg_migrate_plan_step);
+
+ALTER EXTENSION timescaledb
+    DROP TABLE _timescaledb_catalog.continuous_agg;
+
+ALTER TABLE _timescaledb_catalog.continuous_aggs_materialization_invalidation_log
+    DROP CONSTRAINT continuous_aggs_materialization_invalid_materialization_id_fkey;
+
+ALTER TABLE _timescaledb_catalog.continuous_agg_migrate_plan
+    DROP CONSTRAINT continuous_agg_migrate_plan_mat_hypertable_id_fkey;
+
+CREATE TABLE _timescaledb_catalog._tmp_continuous_agg AS
+    SELECT
+        mat_hypertable_id,
+        raw_hypertable_id,
+        NULL::INTEGER AS parent_mat_hypertable_id,
+        user_view_schema,
+        user_view_name,
+        partial_view_schema,
+        partial_view_name,
+        bucket_width,
+        direct_view_schema,
+        direct_view_name,
+        materialized_only,
+        finalized
+    FROM
+        _timescaledb_catalog.continuous_agg
+    ORDER BY
+        mat_hypertable_id;
+
+DROP TABLE _timescaledb_catalog.continuous_agg;
+
+CREATE TABLE _timescaledb_catalog.continuous_agg (
+    mat_hypertable_id integer NOT NULL,
+    raw_hypertable_id integer NOT NULL,
+    parent_mat_hypertable_id integer,
+    user_view_schema name NOT NULL,
+    user_view_name name NOT NULL,
+    partial_view_schema name NOT NULL,
+    partial_view_name name NOT NULL,
+    bucket_width bigint NOT NULL,
+    direct_view_schema name NOT NULL,
+    direct_view_name name NOT NULL,
+    materialized_only bool NOT NULL DEFAULT FALSE,
+    finalized bool NOT NULL DEFAULT TRUE,
+    -- table constraints
+    CONSTRAINT continuous_agg_pkey PRIMARY KEY (mat_hypertable_id),
+    CONSTRAINT continuous_agg_partial_view_schema_partial_view_name_key UNIQUE (partial_view_schema, partial_view_name),
+    CONSTRAINT continuous_agg_user_view_schema_user_view_name_key UNIQUE (user_view_schema, user_view_name),
+    CONSTRAINT continuous_agg_mat_hypertable_id_fkey
+        FOREIGN KEY (mat_hypertable_id) REFERENCES _timescaledb_catalog.hypertable (id) ON DELETE CASCADE,
+    CONSTRAINT continuous_agg_raw_hypertable_id_fkey
+        FOREIGN KEY (raw_hypertable_id) REFERENCES _timescaledb_catalog.hypertable (id) ON DELETE CASCADE,
+    CONSTRAINT continuous_agg_parent_mat_hypertable_id_fkey
+        FOREIGN KEY (parent_mat_hypertable_id)
+        REFERENCES _timescaledb_catalog.continuous_agg (mat_hypertable_id) ON DELETE CASCADE
+);
+
+INSERT INTO _timescaledb_catalog.continuous_agg
+SELECT * FROM _timescaledb_catalog._tmp_continuous_agg;
+DROP TABLE _timescaledb_catalog._tmp_continuous_agg;
+
+CREATE INDEX continuous_agg_raw_hypertable_id_idx ON _timescaledb_catalog.continuous_agg (raw_hypertable_id);
+
+SELECT pg_catalog.pg_extension_config_dump('_timescaledb_catalog.continuous_agg', '');
+
+GRANT SELECT ON TABLE _timescaledb_catalog.continuous_agg TO PUBLIC;
+
+ALTER TABLE _timescaledb_catalog.continuous_aggs_materialization_invalidation_log
+    ADD CONSTRAINT continuous_aggs_materialization_invalid_materialization_id_fkey
+        FOREIGN KEY (materialization_id)
+        REFERENCES _timescaledb_catalog.continuous_agg(mat_hypertable_id) ON DELETE CASCADE;
+
+ALTER TABLE _timescaledb_catalog.continuous_agg_migrate_plan
+    ADD CONSTRAINT continuous_agg_migrate_plan_mat_hypertable_id_fkey
+        FOREIGN KEY (mat_hypertable_id)
+        REFERENCES _timescaledb_catalog.continuous_agg (mat_hypertable_id);
+
+ANALYZE _timescaledb_catalog.continuous_agg;

sql/updates/reverse-dev.sql

@@ -168,7 +168,7 @@ LANGUAGE C VOLATILE STRICT;
 DROP VIEW IF EXISTS timescaledb_information.jobs;
 DROP VIEW IF EXISTS timescaledb_information.job_stats;
 
--- now need to rebuild the table 
+-- now need to rebuild the table
 ALTER TABLE _timescaledb_internal.bgw_job_stat
       DROP CONSTRAINT bgw_job_stat_job_id_fkey;
 ALTER TABLE _timescaledb_internal.bgw_policy_chunk_stats
@@ -178,8 +178,6 @@ ALTER TABLE _timescaledb_internal.bgw_policy_chunk_stats
 CREATE TABLE _timescaledb_config.bgw_job_tmp AS SELECT * FROM _timescaledb_config.bgw_job;
 ALTER EXTENSION timescaledb DROP TABLE _timescaledb_config.bgw_job;
 ALTER EXTENSION timescaledb DROP SEQUENCE _timescaledb_config.bgw_job_id_seq;
--- ALTER TABLE _timescaledb_internal.bgw_job_stat DROP CONSTRAINT IF EXISTS bgw_job_stat_job_id_fkey;
--- ALTER TABLE _timescaledb_internal.bgw_policy_chunk_stats DROP CONSTRAINT IF EXISTS bgw_policy_chunk_stats_job_id_fkey;
 
 CREATE TABLE _timescaledb_internal.tmp_bgw_job_seq_value AS SELECT last_value, is_called FROM _timescaledb_config.bgw_job_id_seq;
 DROP TABLE _timescaledb_config.bgw_job;
@@ -202,7 +200,7 @@ CREATE TABLE _timescaledb_config.bgw_job (
   scheduled bool NOT NULL DEFAULT TRUE,
   hypertable_id integer REFERENCES _timescaledb_catalog.hypertable (id) ON DELETE CASCADE,
   config jsonb,
-  check_schema NAME, 
+  check_schema NAME,
   check_name NAME
 );
 
@@ -235,9 +233,9 @@ CREATE TABLE _timescaledb_internal.tmp_dimension_seq_value AS
 SELECT last_value, is_called FROM _timescaledb_catalog.dimension_id_seq;
 
 --drop foreign keys on dimension table
-ALTER TABLE _timescaledb_catalog.dimension_partition DROP CONSTRAINT 
+ALTER TABLE _timescaledb_catalog.dimension_partition DROP CONSTRAINT
 dimension_partition_dimension_id_fkey;
-ALTER TABLE _timescaledb_catalog.dimension_slice DROP CONSTRAINT 
+ALTER TABLE _timescaledb_catalog.dimension_slice DROP CONSTRAINT
 dimension_slice_dimension_id_fkey;
 
 --drop dependent views
@@ -290,11 +288,11 @@ SELECT pg_catalog.pg_extension_config_dump('_timescaledb_catalog.dimension', '')
 SELECT pg_catalog.pg_extension_config_dump(pg_get_serial_sequence('_timescaledb_catalog.dimension', 'id'), '');
 
 --add the foreign key constraints
-ALTER TABLE _timescaledb_catalog.dimension_partition ADD CONSTRAINT 
-dimension_partition_dimension_id_fkey FOREIGN KEY (dimension_id) 
-REFERENCES _timescaledb_catalog.dimension(id) ON DELETE CASCADE; 
+ALTER TABLE _timescaledb_catalog.dimension_partition ADD CONSTRAINT
+dimension_partition_dimension_id_fkey FOREIGN KEY (dimension_id)
+REFERENCES _timescaledb_catalog.dimension(id) ON DELETE CASCADE;
 ALTER TABLE _timescaledb_catalog.dimension_slice ADD CONSTRAINT
-dimension_slice_dimension_id_fkey FOREIGN KEY (dimension_id) 
+dimension_slice_dimension_id_fkey FOREIGN KEY (dimension_id)
 REFERENCES _timescaledb_catalog.dimension(id) ON DELETE CASCADE;
 
 --cleanup
@@ -311,3 +309,123 @@ DROP INDEX _timescaledb_catalog.chunk_data_node_node_name_idx;
 DROP FUNCTION @extschema@.alter_data_node;
 
 DROP FUNCTION _timescaledb_internal.frozen_chunk_modify_blocker;
+
+--
+-- Prevent downgrading if there are hierarchical continuous aggregates
+--
+DO
+$$
+DECLARE
+    caggs_hierarchical TEXT;
+    caggs_count INTEGER;
+BEGIN
+    SELECT
+        string_agg(format('%I.%I', user_view_schema, user_view_name), ', '),
+        count(*)
+    INTO
+        caggs_hierarchical,
+        caggs_count
+    FROM
+        _timescaledb_catalog.continuous_agg
+    WHERE
+        parent_mat_hypertable_id IS NOT NULL;
+
+    IF caggs_count > 0 THEN
+        RAISE EXCEPTION 'Downgrade is not possible because there are % hierarchical continuous aggregates: %', caggs_count, caggs_nested
+            USING HINT = 'Remove the corresponding continuous aggregates manually before downgrading';
+    END IF;
+END;
+$$
+LANGUAGE 'plpgsql';
+
+--
+-- Rebuild the catalog table `_timescaledb_catalog.continuous_agg`
+--
+DROP VIEW IF EXISTS timescaledb_information.hypertables;
+DROP VIEW IF EXISTS timescaledb_information.continuous_aggregates;
+DROP PROCEDURE IF EXISTS @extschema@.cagg_migrate (REGCLASS, BOOLEAN, BOOLEAN);
+DROP FUNCTION IF EXISTS _timescaledb_internal.cagg_migrate_pre_validation (TEXT, TEXT, TEXT);
+DROP PROCEDURE IF EXISTS _timescaledb_internal.cagg_migrate_create_plan (_timescaledb_catalog.continuous_agg, TEXT, BOOLEAN, BOOLEAN);
+DROP FUNCTION IF EXISTS _timescaledb_internal.cagg_migrate_plan_exists (INTEGER);
+DROP PROCEDURE IF EXISTS _timescaledb_internal.cagg_migrate_execute_plan (_timescaledb_catalog.continuous_agg);
+DROP PROCEDURE IF EXISTS _timescaledb_internal.cagg_migrate_execute_create_new_cagg (_timescaledb_catalog.continuous_agg, _timescaledb_catalog.continuous_agg_migrate_plan_step);
+DROP PROCEDURE IF EXISTS _timescaledb_internal.cagg_migrate_execute_disable_policies (_timescaledb_catalog.continuous_agg, _timescaledb_catalog.continuous_agg_migrate_plan_step);
+DROP PROCEDURE IF EXISTS _timescaledb_internal.cagg_migrate_execute_enable_policies (_timescaledb_catalog.continuous_agg, _timescaledb_catalog.continuous_agg_migrate_plan_step);
+DROP PROCEDURE IF EXISTS _timescaledb_internal.cagg_migrate_execute_copy_policies (_timescaledb_catalog.continuous_agg, _timescaledb_catalog.continuous_agg_migrate_plan_step);
+DROP PROCEDURE IF EXISTS _timescaledb_internal.cagg_migrate_execute_refresh_new_cagg (_timescaledb_catalog.continuous_agg, _timescaledb_catalog.continuous_agg_migrate_plan_step);
+DROP PROCEDURE IF EXISTS _timescaledb_internal.cagg_migrate_execute_copy_data (_timescaledb_catalog.continuous_agg, _timescaledb_catalog.continuous_agg_migrate_plan_step);
+DROP PROCEDURE IF EXISTS _timescaledb_internal.cagg_migrate_execute_override_cagg (_timescaledb_catalog.continuous_agg, _timescaledb_catalog.continuous_agg_migrate_plan_step);
+DROP PROCEDURE IF EXISTS _timescaledb_internal.cagg_migrate_execute_drop_old_cagg (_timescaledb_catalog.continuous_agg, _timescaledb_catalog.continuous_agg_migrate_plan_step);
+
+ALTER EXTENSION timescaledb
+    DROP TABLE _timescaledb_catalog.continuous_agg;
+
+ALTER TABLE _timescaledb_catalog.continuous_aggs_materialization_invalidation_log
+    DROP CONSTRAINT continuous_aggs_materialization_invalid_materialization_id_fkey;
+
+ALTER TABLE _timescaledb_catalog.continuous_agg_migrate_plan
+    DROP CONSTRAINT continuous_agg_migrate_plan_mat_hypertable_id_fkey;
+
+CREATE TABLE _timescaledb_catalog._tmp_continuous_agg AS
+    SELECT
+        mat_hypertable_id,
+        raw_hypertable_id,
+        user_view_schema,
+        user_view_name,
+        partial_view_schema,
+        partial_view_name,
+        bucket_width,
+        direct_view_schema,
+        direct_view_name,
+        materialized_only,
+        finalized
+    FROM
+        _timescaledb_catalog.continuous_agg
+    ORDER BY
+        mat_hypertable_id;
+
+DROP TABLE _timescaledb_catalog.continuous_agg;
+
+CREATE TABLE _timescaledb_catalog.continuous_agg (
+    mat_hypertable_id integer NOT NULL,
+    raw_hypertable_id integer NOT NULL,
+    user_view_schema name NOT NULL,
+    user_view_name name NOT NULL,
+    partial_view_schema name NOT NULL,
+    partial_view_name name NOT NULL,
+    bucket_width bigint NOT NULL,
+    direct_view_schema name NOT NULL,
+    direct_view_name name NOT NULL,
+    materialized_only bool NOT NULL DEFAULT FALSE,
+    finalized bool NOT NULL DEFAULT TRUE,
+    -- table constraints
+    CONSTRAINT continuous_agg_pkey PRIMARY KEY (mat_hypertable_id),
+    CONSTRAINT continuous_agg_partial_view_schema_partial_view_name_key UNIQUE (partial_view_schema, partial_view_name),
+    CONSTRAINT continuous_agg_user_view_schema_user_view_name_key UNIQUE (user_view_schema, user_view_name),
+    CONSTRAINT continuous_agg_mat_hypertable_id_fkey
+        FOREIGN KEY (mat_hypertable_id) REFERENCES _timescaledb_catalog.hypertable (id) ON DELETE CASCADE,
+    CONSTRAINT continuous_agg_raw_hypertable_id_fkey
+        FOREIGN KEY (raw_hypertable_id) REFERENCES _timescaledb_catalog.hypertable (id) ON DELETE CASCADE
+);
+
+INSERT INTO _timescaledb_catalog.continuous_agg
+SELECT * FROM _timescaledb_catalog._tmp_continuous_agg;
+DROP TABLE _timescaledb_catalog._tmp_continuous_agg;
+
+CREATE INDEX continuous_agg_raw_hypertable_id_idx ON _timescaledb_catalog.continuous_agg (raw_hypertable_id);
+
+SELECT pg_catalog.pg_extension_config_dump('_timescaledb_catalog.continuous_agg', '');
+
+GRANT SELECT ON TABLE _timescaledb_catalog.continuous_agg TO PUBLIC;
+
+ALTER TABLE _timescaledb_catalog.continuous_aggs_materialization_invalidation_log
+    ADD CONSTRAINT continuous_aggs_materialization_invalid_materialization_id_fkey
+        FOREIGN KEY (materialization_id)
+        REFERENCES _timescaledb_catalog.continuous_agg(mat_hypertable_id) ON DELETE CASCADE;
+
+ALTER TABLE _timescaledb_catalog.continuous_agg_migrate_plan
+    ADD CONSTRAINT continuous_agg_migrate_plan_mat_hypertable_id_fkey
+        FOREIGN KEY (mat_hypertable_id)
+        REFERENCES _timescaledb_catalog.continuous_agg (mat_hypertable_id);
+
+ANALYZE _timescaledb_catalog.continuous_agg;

src/ts_catalog/catalog.c

@@ -81,8 +81,8 @@ static const TableInfoDef catalog_table_names[_MAX_CATALOG_TABLES + 1] = {
 		.table_name = BGW_POLICY_CHUNK_STATS_TABLE_NAME,
 	},
 	[CONTINUOUS_AGG] = {
-			.schema_name = CATALOG_SCHEMA_NAME,
-			.table_name = CONTINUOUS_AGG_TABLE_NAME,
+		.schema_name = CATALOG_SCHEMA_NAME,
+		.table_name = CONTINUOUS_AGG_TABLE_NAME,
 	},
 	[CONTINUOUS_AGGS_HYPERTABLE_INVALIDATION_LOG] = {
 		.schema_name = CATALOG_SCHEMA_NAME,

src/ts_catalog/catalog.h

@@ -938,6 +938,7 @@ typedef enum Anum_continuous_agg
 {
 	Anum_continuous_agg_mat_hypertable_id = 1,
 	Anum_continuous_agg_raw_hypertable_id,
+	Anum_continuous_agg_parent_mat_hypertable_id,
 	Anum_continuous_agg_user_view_schema,
 	Anum_continuous_agg_user_view_name,
 	Anum_continuous_agg_partial_view_schema,
@@ -956,6 +957,7 @@ typedef struct FormData_continuous_agg
 {
 	int32 mat_hypertable_id;
 	int32 raw_hypertable_id;
+	int32 parent_mat_hypertable_id; /* Nested Continuous Aggregate */
 	NameData user_view_schema;
 	NameData user_view_name;
 	NameData partial_view_schema;