Merge 5683a2b976 into 55a0d1f730

src/backend/distributed/sql/udfs/create_time_partitions/12.2-1.sql

@@ -0,0 +1,58 @@
+CREATE OR REPLACE FUNCTION pg_catalog.create_time_partitions(
+    table_name regclass,
+    partition_interval INTERVAL,
+    end_at timestamptz,
+    start_from timestamptz DEFAULT now())
+returns boolean
+LANGUAGE plpgsql
+AS $$
+DECLARE
+    -- partitioned table name
+    schema_name_text name;
+    table_name_text name;
+
+    -- record for to-be-created partition
+    missing_partition_record record;
+
+    -- result indiciates whether any partitions were created
+    partition_created bool := false;
+BEGIN
+    IF start_from >= end_at THEN
+        RAISE 'start_from (%) must be older than end_at (%)', start_from, end_at;
+    END IF;
+
+    SELECT nspname, relname
+    INTO schema_name_text, table_name_text
+    FROM pg_class JOIN pg_namespace ON pg_class.relnamespace = pg_namespace.oid
+    WHERE pg_class.oid = table_name::oid;
+
+    -- Get missing partition range info using the get_missing_partition_ranges
+    -- and create partitions using that info.
+    FOR missing_partition_record IN
+        SELECT *
+        FROM get_missing_time_partition_ranges(table_name, partition_interval, end_at, start_from)
+    LOOP
+        EXECUTE format('CREATE TABLE %I.%I (LIKE %I INCLUDING DEFAULTS INCLUDING CONSTRAINTS)',
+        schema_name_text,
+        missing_partition_record.partition_name,
+        table_name_text);
+        EXECUTE format('ALTER TABLE %I.%I ATTACH PARTITION %I.%I FOR VALUES FROM (%L) TO (%L)',
+        schema_name_text,
+        table_name_text,
+        schema_name_text,
+        missing_partition_record.partition_name,
+        missing_partition_record.range_from_value,
+        missing_partition_record.range_to_value);
+        RAISE NOTICE 'created partition % for table %', missing_partition_record.partition_name, table_name_text;
+        partition_created := true;
+    END LOOP;
+
+    RETURN partition_created;
+END;
+$$;
+COMMENT ON FUNCTION pg_catalog.create_time_partitions(
+    table_name regclass,
+    partition_interval INTERVAL,
+    end_at timestamptz,
+    start_from timestamptz)
+IS 'create time partitions for the given range';

src/backend/distributed/sql/udfs/drop_old_time_partitions/12.2-1.sql

@@ -0,0 +1,69 @@
+CREATE OR REPLACE PROCEDURE pg_catalog.drop_old_time_partitions(
+    table_name regclass,
+    older_than timestamptz)
+LANGUAGE plpgsql
+AS $$
+DECLARE
+    -- properties of the partitioned table
+    number_of_partition_columns int;
+    partition_column_index int;
+    partition_column_type regtype;
+
+    -- used to support dynamic type casting between the partition column type and timestamptz
+    custom_cast text;
+    is_partition_column_castable boolean;
+    older_partitions_query text;
+
+    r record;
+BEGIN
+    -- check whether the table is time partitioned table, if not error out
+    SELECT partnatts, partattrs[0]
+    INTO number_of_partition_columns, partition_column_index
+    FROM pg_catalog.pg_partitioned_table
+    WHERE partrelid = table_name;
+
+    IF NOT FOUND THEN
+        RAISE '% is not partitioned', table_name::text;
+    ELSIF number_of_partition_columns <> 1 THEN
+        RAISE 'partitioned tables with multiple partition columns are not supported';
+    END IF;
+
+    -- get datatype here to check interval-table type
+    SELECT atttypid
+    INTO partition_column_type
+    FROM pg_attribute
+    WHERE attrelid = table_name::oid
+    AND attnum = partition_column_index;
+
+    -- we currently only support partitioning by date, timestamp, and timestamptz
+    custom_cast = '';
+    IF partition_column_type <> 'date'::regtype
+    AND partition_column_type <> 'timestamp'::regtype
+    AND partition_column_type <> 'timestamptz'::regtype  THEN
+      SELECT EXISTS(SELECT OID FROM pg_cast WHERE castsource = partition_column_type AND casttarget = 'timestamptz'::regtype) AND
+             EXISTS(SELECT OID FROM pg_cast WHERE castsource = 'timestamptz'::regtype AND casttarget = partition_column_type)
+      INTO is_partition_column_castable;
+      IF not is_partition_column_castable THEN
+        RAISE 'type of the partition column of the table % must be date, timestamp or timestamptz', table_name;
+      END IF;
+      custom_cast = format('::%s', partition_column_type);
+    END IF;
+
+    older_partitions_query = format('SELECT partition, nspname AS schema_name, relname AS table_name, from_value, to_value
+        FROM pg_catalog.time_partitions, pg_catalog.pg_class c, pg_catalog.pg_namespace n
+        WHERE parent_table = $1 AND partition = c.oid AND c.relnamespace = n.oid
+        AND to_value IS NOT NULL
+        AND to_value%1$s::timestamptz <= $2
+        ORDER BY to_value%1$s::timestamptz', custom_cast);
+    FOR r IN EXECUTE older_partitions_query USING table_name, older_than
+    LOOP
+        RAISE NOTICE 'dropping % with start time % and end time % using DETACH PARTITION partition_name AND THEN DROP IT. ', r.partition, r.from_value, r.to_value;
+        EXECUTE format('ALTER TABLE %I.%I DETACH PARTITION %I',r.schema_name, r.table_name, r.partition);
+        EXECUTE format('DROP TABLE %I.%I', r.schema_name, r.table_name);
+    END LOOP;
+END;
+$$;
+COMMENT ON PROCEDURE pg_catalog.drop_old_time_partitions(
+    table_name regclass,
+    older_than timestamptz)
+IS 'drop old partitions of a time-partitioned table';