create_partition_id.sql

CREATE FUNCTION @extschema@.create_partition_id(p_parent_table text, p_partition_ids bigint[], p_analyze boolean DEFAULT true, p_start_partition text DEFAULT NULL) RETURNS boolean
    LANGUAGE plpgsql 
    AS $$
DECLARE

ex_context              text;
ex_detail               text;
ex_hint                 text;
ex_message              text;
v_all                   text[] := ARRAY['SELECT', 'INSERT', 'UPDATE', 'DELETE', 'TRUNCATE', 'REFERENCES', 'TRIGGER'];
v_analyze               boolean := FALSE;
v_control               text;
v_control_type          text;
v_exists                text;
v_grantees              text[];
v_hasoids               boolean;
v_id                    bigint;
v_inherit_fk            boolean;
v_inherit_privileges    boolean;
v_job_id                bigint;
v_jobmon                boolean;
v_jobmon_schema         text;
v_new_search_path       text;
v_old_search_path       text;
v_parent_grant          record;
v_parent_schema         text;
v_parent_tablename      text;
v_parent_tablespace     text;
v_partition_interval    bigint;
v_partition_created     boolean := false;
v_partition_name        text;
v_partition_type        text;
v_publications          text[];
v_revoke                text;
v_row                   record;
v_sql                   text;
v_step_id               bigint;
v_sub_control           text;
v_sub_partition_type    text; 
v_sub_id_max            bigint;
v_sub_id_min            bigint;
v_template_table        text;
v_unlogged              char;

BEGIN
/*
 * Function to create id partitions
 */

SELECT control
    , partition_type
    , partition_interval
    , inherit_fk
    , jobmon
    , template_table
    , publications
    , inherit_privileges
INTO v_control
    , v_partition_type
    , v_partition_interval
    , v_inherit_fk
    , v_jobmon
    , v_template_table
    , v_publications
    , v_inherit_privileges
FROM @extschema@.part_config
WHERE parent_table = p_parent_table;

IF NOT FOUND THEN
    RAISE EXCEPTION 'ERROR: no config found for %', p_parent_table;
END IF;

SELECT n.nspname, c.relname, t.spcname 
INTO v_parent_schema, v_parent_tablename, v_parent_tablespace 
FROM pg_catalog.pg_class c
JOIN pg_catalog.pg_namespace n ON c.relnamespace = n.oid
LEFT OUTER JOIN pg_catalog.pg_tablespace t ON c.reltablespace = t.oid
WHERE n.nspname = split_part(p_parent_table, '.', 1)::name

AND c.relname = split_part(p_parent_table, '.', 2)::name;

SELECT general_type INTO v_control_type FROM @extschema@.check_control_type(v_parent_schema, v_parent_tablename, v_control);
IF v_control_type <> 'id' THEN
    RAISE EXCEPTION 'ERROR: Given parent table is not set up for id/serial partitioning';
END IF;

SELECT current_setting('search_path') INTO v_old_search_path;
IF length(v_old_search_path) > 0 THEN
   v_new_search_path := '@extschema@,pg_temp,'||v_old_search_path;
ELSE
    v_new_search_path := '@extschema@,pg_temp';
END IF;
IF v_jobmon THEN
    SELECT nspname INTO v_jobmon_schema FROM pg_catalog.pg_namespace n, pg_catalog.pg_extension e WHERE e.extname = 'pg_jobmon'::name AND e.extnamespace = n.oid;
    IF v_jobmon_schema IS NOT NULL THEN
        v_new_search_path := format('%s,%s',v_jobmon_schema, v_new_search_path);
    END IF;
END IF;
EXECUTE format('SELECT set_config(%L, %L, %L)', 'search_path', v_new_search_path, 'false');

-- Determine if this table is a child of a subpartition parent. If so, get limits of what child tables can be created based on parent suffix
SELECT sub_min::bigint, sub_max::bigint INTO v_sub_id_min, v_sub_id_max FROM @extschema@.check_subpartition_limits(p_parent_table, 'id');

IF v_jobmon_schema IS NOT NULL THEN
    v_job_id := add_job(format('PARTMAN CREATE TABLE: %s', p_parent_table));
END IF;

FOREACH v_id IN ARRAY p_partition_ids LOOP
-- Do not create the child table if it's outside the bounds of the top parent. 
    IF v_sub_id_min IS NOT NULL THEN
        IF v_id < v_sub_id_min OR v_id >= v_sub_id_max THEN
            CONTINUE;
        END IF;
    END IF;

    v_partition_name := @extschema@.check_name_length(v_parent_tablename, v_id::text, TRUE);
    -- If child table already exists, skip creation
    -- Have to check pg_class because if subpartitioned, table will not be in pg_tables
    SELECT c.relname INTO v_exists 
    FROM pg_catalog.pg_class c
    JOIN pg_catalog.pg_namespace n ON c.relnamespace = n.oid
    WHERE n.nspname = v_parent_schema::name AND c.relname = v_partition_name::name;
    IF v_exists IS NOT NULL THEN
        CONTINUE;
    END IF;

    -- Ensure analyze is run if a new partition is created. Otherwise if one isn't, will be false and analyze will be skipped
    v_analyze := TRUE;

    IF v_jobmon_schema IS NOT NULL THEN
        v_step_id := add_step(v_job_id, 'Creating new partition '||v_partition_name||' with interval from '||v_id||' to '||(v_id + v_partition_interval)-1);
    END IF;

    v_sql := 'CREATE';

    -- As of PG12, the unlogged/logged status of a native parent table cannot be changed via an ALTER TABLE in order to affect its children.
    -- As of v4.2x, the unlogged state will be managed via the template table    
    SELECT relpersistence INTO v_unlogged 
    FROM pg_catalog.pg_class c
    JOIN pg_catalog.pg_namespace n ON c.relnamespace = n.oid
    WHERE c.relname = v_parent_tablename::name
    AND n.nspname = v_parent_schema::name;
    IF v_unlogged = 'u' and v_partition_type != 'native'  THEN
        v_sql := v_sql || ' UNLOGGED';
    END IF;

    -- Close parentheses on LIKE are below due to differing requirements of native subpartitioning
    -- Same INCLUDING list is used in create_parent()
    v_sql := v_sql || format(' TABLE %I.%I (LIKE %I.%I INCLUDING DEFAULTS INCLUDING CONSTRAINTS INCLUDING STORAGE INCLUDING COMMENTS '
            , v_parent_schema
            , v_partition_name
            , v_parent_schema
            , v_parent_tablename);

    IF current_setting('server_version_num')::int >= 120000 THEN
        v_sql := v_sql || ' INCLUDING GENERATED ';
    END IF;

    SELECT sub_partition_type, sub_control INTO v_sub_partition_type, v_sub_control 
    FROM @extschema@.part_config_sub 
    WHERE sub_parent = p_parent_table;
    IF v_sub_partition_type = 'native' THEN
        -- INCLUDING INDEXES isn't necessary for native partitioning. It isn't supported in v10 and 
	    --   for v11+ index inheritance is automatically handled when the partition is attached
        v_sql := v_sql || format(') PARTITION BY RANGE (%I) ', v_sub_control);
    ELSE
        v_sql := v_sql || format(' INCLUDING INDEXES) ', v_sub_control);
    END IF;


    IF current_setting('server_version_num')::int < 120000 THEN
        -- column removed from pgclass in pg12
        SELECT relhasoids INTO v_hasoids 
        FROM pg_catalog.pg_class c
        JOIN pg_catalog.pg_namespace n ON c.relnamespace = n.oid
        WHERE c.relname = v_parent_tablename::name
        AND n.nspname = v_parent_schema::name;
        IF v_hasoids IS TRUE THEN
            v_sql := v_sql || ' WITH (OIDS)';
        END IF;
    END IF;

    RAISE DEBUG 'create_partition_id v_sql: %', v_sql;
    EXECUTE v_sql;

    IF v_partition_type = 'native' THEN

        IF current_setting('server_version_num')::int >= 120000 THEN
            -- PG12 fixed tablespace marking on the parent of a native partition set
            -- Versions older than 12 handle tablespace setting via inherit_template_properties() call below
            IF v_parent_tablespace IS NOT NULL THEN
                EXECUTE format('ALTER TABLE %I.%I SET TABLESPACE %I', v_parent_schema, v_partition_name, v_parent_tablespace);
            END IF;
        END IF;

        IF v_template_table IS NOT NULL THEN
            PERFORM @extschema@.inherit_template_properties(p_parent_table, v_parent_schema, v_partition_name);
        END IF;

        EXECUTE format('ALTER TABLE %I.%I ATTACH PARTITION %I.%I FOR VALUES FROM (%L) TO (%L)'
            , v_parent_schema
            , v_parent_tablename
            , v_parent_schema
            , v_partition_name
            , v_id
            , v_id + v_partition_interval);

    ELSE -- non-native

        IF v_parent_tablespace IS NOT NULL THEN
            EXECUTE format('ALTER TABLE %I.%I SET TABLESPACE %I', v_parent_schema, v_partition_name, v_parent_tablespace);
        END IF;

        EXECUTE format('ALTER TABLE %I.%I ADD CONSTRAINT %I CHECK (%I >= %s AND %I < %s )'
            , v_parent_schema
            , v_partition_name
            , v_partition_name||'_partition_check'
            , v_control
            , v_id
            , v_control
            , v_id + v_partition_interval);

        EXECUTE format('ALTER TABLE %I.%I INHERIT %I.%I', v_parent_schema, v_partition_name, v_parent_schema, v_parent_tablename);

        -- Indexes cannot be created on the parent, so clustering cannot be used for native yet.
        PERFORM @extschema@.apply_cluster(v_parent_schema, v_parent_tablename, v_parent_schema, v_partition_name);

        -- Foreign keys to other tables not supported on native parent tables
        IF v_inherit_fk THEN
            PERFORM @extschema@.apply_foreign_keys(p_parent_table, v_parent_schema||'.'||v_partition_name, v_job_id);
        END IF;

    END IF;
    
    -- NOTE: Privileges not automatically inherited for native. Only do so if config flag is set
    IF v_partition_type != 'native' OR (v_partition_type = 'native' AND v_inherit_privileges = TRUE) THEN
        PERFORM @extschema@.apply_privileges(v_parent_schema, v_parent_tablename, v_parent_schema, v_partition_name, v_job_id);
    END IF;

    IF v_jobmon_schema IS NOT NULL THEN
        PERFORM update_step(v_step_id, 'OK', 'Done');
    END IF;

    -- Will only loop once and only if sub_partitioning is actually configured
    -- This seemed easier than assigning a bunch of variables then doing an IF condition
    -- This column list must be kept consistent between: 
    --   create_parent, check_subpart_sameconfig, create_partition_id, create_partition_time, dump_partitioned_table_definition, and table definition
    FOR v_row IN 
        SELECT sub_parent
            , sub_partition_type
            , sub_control
            , sub_partition_interval
            , sub_constraint_cols
            , sub_premake
            , sub_optimize_trigger
            , sub_optimize_constraint
            , sub_epoch
            , sub_inherit_fk
            , sub_retention
            , sub_retention_schema
            , sub_retention_keep_table
            , sub_retention_keep_index
            , sub_infinite_time_partitions
            , sub_automatic_maintenance
            , sub_jobmon
            , sub_trigger_exception_handling
            , sub_upsert
            , sub_trigger_return_null
            , sub_template_table
            , sub_inherit_privileges
            , sub_constraint_valid
            , sub_subscription_refresh
            , sub_date_trunc_interval
            , sub_ignore_default_data
        FROM @extschema@.part_config_sub
        WHERE sub_parent = p_parent_table
    LOOP
        IF v_jobmon_schema IS NOT NULL THEN
            v_step_id := add_step(v_job_id, 'Subpartitioning '||v_partition_name);
        END IF;
        v_sql := format('SELECT @extschema@.create_parent(
                 p_parent_table := %L
                , p_control := %L
                , p_type := %L
                , p_interval := %L
                , p_constraint_cols := %L
                , p_premake := %L
                , p_automatic_maintenance := %L
                , p_inherit_fk := %L
                , p_epoch := %L
                , p_template_table := %L
                , p_jobmon := %L
                , p_start_partition := %L 
                , p_date_trunc_interval := %L )'
            , v_parent_schema||'.'||v_partition_name
            , v_row.sub_control
            , v_row.sub_partition_type
            , v_row.sub_partition_interval
            , v_row.sub_constraint_cols
            , v_row.sub_premake
            , v_row.sub_automatic_maintenance
            , v_row.sub_inherit_fk
            , v_row.sub_epoch
            , v_row.sub_template_table
            , v_row.sub_jobmon
            , p_start_partition
            , v_row.sub_date_trunc_interval);
        RAISE DEBUG 'create_partition_id (create_parent loop): %', v_sql;
        EXECUTE v_sql;

        UPDATE @extschema@.part_config SET 
            retention_schema = v_row.sub_retention_schema
            , retention_keep_table = v_row.sub_retention_keep_table
            , retention_keep_index = v_row.sub_retention_keep_index
            , optimize_trigger = v_row.sub_optimize_trigger
            , optimize_constraint = v_row.sub_optimize_constraint
            , infinite_time_partitions = v_row.sub_infinite_time_partitions
            , trigger_exception_handling = v_row.sub_trigger_exception_handling
            , upsert = v_row.sub_upsert
            , inherit_privileges = v_row.sub_inherit_privileges
            , trigger_return_null = v_row.sub_trigger_return_null
            , constraint_valid = v_row.sub_constraint_valid
            , subscription_refresh = v_row.sub_subscription_refresh
            , ignore_default_data = v_row.sub_ignore_default_data
        WHERE parent_table = v_parent_schema||'.'||v_partition_name;

        IF v_jobmon_schema IS NOT NULL THEN
            PERFORM update_step(v_step_id, 'OK', 'Done');
        END IF;

    END LOOP; -- end sub partitioning LOOP
    
    -- Manage additonal constraints if set
    PERFORM @extschema@.apply_constraints(p_parent_table, p_job_id := v_job_id);

    IF v_publications IS NOT NULL THEN
        -- NOTE: Native publication inheritance is only supported on PG14+
        PERFORM @extschema@.apply_publications(p_parent_table, v_parent_schema, v_partition_name);
    END IF;

    v_partition_created := true;

END LOOP;

-- v_analyze is a local check if a new table is made.
-- p_analyze is a parameter to say whether to run the analyze at all. Used by create_parent() to avoid long exclusive lock or run_maintenence() to avoid long creation runs.
IF v_analyze AND p_analyze THEN
    IF v_jobmon_schema IS NOT NULL THEN
        v_step_id := add_step(v_job_id, format('Analyzing partition set: %s', p_parent_table));
    END IF;

    EXECUTE format('ANALYZE %I.%I', v_parent_schema, v_parent_tablename);

    IF v_jobmon_schema IS NOT NULL THEN
        PERFORM update_step(v_step_id, 'OK', 'Done');
    END IF;
END IF;

IF v_jobmon_schema IS NOT NULL THEN
    IF v_partition_created = false THEN
        v_step_id := add_step(v_job_id, format('No partitions created for partition set: %s', p_parent_table));
        PERFORM update_step(v_step_id, 'OK', 'Done');
    END IF;

    PERFORM close_job(v_job_id);
END IF;
 
EXECUTE format('SELECT set_config(%L, %L, %L)', 'search_path', v_old_search_path, 'false');

RETURN v_partition_created;

EXCEPTION
    WHEN OTHERS THEN
        GET STACKED DIAGNOSTICS ex_message = MESSAGE_TEXT,
                                ex_context = PG_EXCEPTION_CONTEXT,
                                ex_detail = PG_EXCEPTION_DETAIL,
                                ex_hint = PG_EXCEPTION_HINT;
        IF v_jobmon_schema IS NOT NULL THEN
            IF v_job_id IS NULL THEN
                EXECUTE format('SELECT %I.add_job(''PARTMAN CREATE TABLE: %s'')', v_jobmon_schema, p_parent_table) INTO v_job_id;
                EXECUTE format('SELECT %I.add_step(%s, ''EXCEPTION before job logging started'')', v_jobmon_schema, v_job_id, p_parent_table) INTO v_step_id;
            ELSIF v_step_id IS NULL THEN
                EXECUTE format('SELECT %I.add_step(%s, ''EXCEPTION before first step logged'')', v_jobmon_schema, v_job_id) INTO v_step_id;
            END IF;
            EXECUTE format('SELECT %I.update_step(%s, ''CRITICAL'', %L)', v_jobmon_schema, v_step_id, 'ERROR: '||coalesce(SQLERRM,'unknown'));
            EXECUTE format('SELECT %I.fail_job(%s)', v_jobmon_schema, v_job_id);
        END IF;
        RAISE EXCEPTION '%
CONTEXT: %
DETAIL: %
HINT: %', ex_message, ex_context, ex_detail, ex_hint; 
END
$$;