-- New configuration option for retention system that allows child tables that are eligible for removal to instead be moved to another schema. Set the "retention_schema" option in the configuration table to move the table to the designated schema instead of dropping it. This overrides the retention_keep_table & retention_keep_index options.
-- New python script, dump_partition.py, that will dump any tables found in a given schema using pg_dump, create a SHA-512 hash of the dumped file and then drop the table from the database.
-- The combination of the retention_schema option and the dump_partition.py script give a way to reliably dump out tables for archiving when they are no longer needed in the database. Idea for this feature adapted from conversation at PGDay NYC 2013 (lost the card of the individual I was talking with :( ).
-- New function show_partitions() that gives a list of child tables in a partition set. Adapted from fork by https://github.com/ebaptistella
-- Previously the functions that created the new partitions were using only the "INCLUDING DEFAULTS INCLUDING INDEXES" options when using the CREATE TABLE ... (LIKE ...) syntax. This caused some contraints on the parent to be missed in child tables. Changed to include all available options as of PostgreSQL 9.1: INCLUDING DEFAULTS INCLUDING CONSTRAINTS INCLUDING INDEXES INCLUDING STORAGE INCLUDING COMMENTS. Change will apply to all newly created child tables in all partition sets managed by pg_partman. You'll have to go back and manually fix any already existing child tables that may be missing constraints. Issue reported by Nick Ebbitt.
-- Added TAP tests for drop partition functions.
-- Fixed some tap tests to more accurately test for table (non)existance
-- Clarified the drop_partition_id() function's retention parameter meaning.

ALTER TABLE @extschema@.part_config ADD retention_schema text;

CREATE TEMP TABLE pg_partman_preserve_privs_temp (statement text);

INSERT INTO pg_partman_preserve_privs_temp
SELECT 'GRANT EXECUTE ON FUNCTION @extschema@.drop_partition_id(text, bigint, boolean, boolean, text) TO '||array_to_string(array_agg(grantee::text), ',')||';'
FROM information_schema.routine_privileges
WHERE routine_schema = '@extschema@'
AND routine_name = 'drop_partition_id';

INSERT INTO pg_partman_preserve_privs_temp
SELECT 'GRANT EXECUTE ON FUNCTION @extschema@.drop_partition_time(text, interval, boolean, boolean, text) TO '||array_to_string(array_agg(grantee::text), ',')||';'
FROM information_schema.routine_privileges
WHERE routine_schema = '@extschema@'
AND routine_name = 'drop_partition_time';

CREATE FUNCTION replay_preserved_privs() RETURNS void
    LANGUAGE plpgsql
    AS $$
DECLARE
v_row   record;
BEGIN
    FOR v_row IN SELECT statement FROM pg_partman_preserve_privs_temp LOOP
        IF v_row.statement IS NOT NULL THEN
            EXECUTE v_row.statement;
        END IF;
    END LOOP;
END
$$;

DROP FUNCTION drop_partition_id(text, bigint, boolean, boolean);
DROP FUNCTION drop_partition_time(text, interval, boolean, boolean);

/*
 * Function to list all child partitions in a set.
 * Will list all child tables in any inheritance set,
 * not just those managed by pg_partman.
 */
CREATE FUNCTION show_partitions (p_parent_table text) RETURNS SETOF text
    LANGUAGE plpgsql STABLE SECURITY DEFINER
    AS $$
BEGIN

RETURN QUERY EXECUTE '
    SELECT n.nspname::text ||''.''|| c.relname::text AS partition_name FROM
    pg_catalog.pg_inherits h
    JOIN pg_catalog.pg_class c ON c.oid = h.inhrelid
    JOIN pg_catalog.pg_namespace n ON c.relnamespace = n.oid
    WHERE h.inhparent = '||quote_literal(p_parent_table)||'::regclass
    ORDER BY c.relname';
END
$$;


/*
 * Function to create id partitions
 */
CREATE OR REPLACE FUNCTION create_id_partition (p_parent_table text, p_control text, p_interval bigint, p_partition_ids bigint[]) RETURNS text
    LANGUAGE plpgsql SECURITY DEFINER
    AS $$
DECLARE

v_all               text[] := ARRAY['SELECT', 'INSERT', 'UPDATE', 'DELETE', 'TRUNCATE', 'REFERENCES', 'TRIGGER'];
v_grantees          text[];
v_job_id            bigint;
v_jobmon_schema     text;
v_old_search_path   text;
v_parent_grant      record;
v_parent_owner      text;
v_partition_name    text;
v_revoke            text[];
v_step_id           bigint;
v_tablename         text;
v_id                bigint;

BEGIN

SELECT nspname INTO v_jobmon_schema FROM pg_namespace n, pg_extension e WHERE e.extname = 'pg_jobmon' AND e.extnamespace = n.oid;
IF v_jobmon_schema IS NOT NULL THEN
    SELECT current_setting('search_path') INTO v_old_search_path;
    EXECUTE 'SELECT set_config(''search_path'',''@extschema@,'||v_jobmon_schema||''',''false'')';
END IF;

SELECT tableowner INTO v_parent_owner FROM pg_tables WHERE schemaname ||'.'|| tablename = p_parent_table;

FOREACH v_id IN ARRAY p_partition_ids LOOP

    v_partition_name := p_parent_table||'_p'||v_id;

    SELECT schemaname ||'.'|| tablename INTO v_tablename FROM pg_catalog.pg_tables WHERE schemaname ||'.'|| tablename = v_partition_name;

    IF v_tablename IS NOT NULL THEN
        CONTINUE;
    END IF;

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

    IF position('.' in p_parent_table) > 0 THEN
        v_tablename := substring(v_partition_name from position('.' in v_partition_name)+1);
    END IF;

    EXECUTE 'CREATE TABLE '||v_partition_name||' (LIKE '||p_parent_table||' INCLUDING DEFAULTS INCLUDING CONSTRAINTS INCLUDING INDEXES INCLUDING STORAGE INCLUDING COMMENTS)';
    EXECUTE 'ALTER TABLE '||v_partition_name||' ADD CONSTRAINT '||v_tablename||'_partition_check
        CHECK ('||p_control||'>='||quote_literal(v_id)||' AND '||p_control||'<'||quote_literal(v_id + p_interval)||')';
    EXECUTE 'ALTER TABLE '||v_partition_name||' INHERIT '||p_parent_table;

    FOR v_parent_grant IN
        SELECT array_agg(DISTINCT privilege_type::text ORDER BY privilege_type::text) AS types, grantee
        FROM information_schema.table_privileges
        WHERE table_schema ||'.'|| table_name = p_parent_table
        GROUP BY grantee
    LOOP
        EXECUTE 'GRANT '||array_to_string(v_parent_grant.types, ',')||' ON '||v_partition_name||' TO '||v_parent_grant.grantee;
        SELECT array_agg(r) INTO v_revoke FROM (SELECT unnest(v_all) AS r EXCEPT SELECT unnest(v_parent_grant.types)) x;
        IF v_revoke IS NOT NULL THEN
            EXECUTE 'REVOKE '||array_to_string(v_revoke, ',')||' ON '||v_partition_name||' FROM '||v_parent_grant.grantee||' CASCADE';
        END IF;
        v_grantees := array_append(v_grantees, v_parent_grant.grantee::text);
    END LOOP;
    -- Revoke all privileges from roles that have none on the parent
    IF v_grantees IS NOT NULL THEN
        SELECT array_agg(r) INTO v_revoke FROM (
            SELECT DISTINCT grantee::text AS r FROM information_schema.table_privileges WHERE table_schema ||'.'|| table_name = v_partition_name
            EXCEPT
            SELECT unnest(v_grantees)) x;
        IF v_revoke IS NOT NULL THEN
            EXECUTE 'REVOKE ALL ON '||v_partition_name||' FROM '||array_to_string(v_revoke, ',');
        END IF;
    END IF;

    EXECUTE 'ALTER TABLE '||v_partition_name||' OWNER TO '||v_parent_owner;

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

END LOOP;

IF v_jobmon_schema IS NOT NULL THEN
    EXECUTE 'SELECT set_config(''search_path'','''||v_old_search_path||''',''false'')';
END IF;

RETURN v_partition_name;

EXCEPTION
    WHEN OTHERS THEN
        IF v_jobmon_schema IS NOT NULL THEN
            EXECUTE 'SELECT set_config(''search_path'',''@extschema@,'||v_jobmon_schema||''',''false'')';
            IF v_job_id IS NULL THEN
                v_job_id := add_job('PARTMAN CREATE TABLE: '||p_parent_table);
                v_step_id := add_step(v_job_id, 'Partition maintenance for table '||p_parent_table||' failed');
            ELSIF v_step_id IS NULL THEN
                v_step_id := add_step(v_job_id, 'EXCEPTION before first step logged');
            END IF;
            PERFORM update_step(v_step_id, 'BAD', 'ERROR: '||coalesce(SQLERRM,'unknown'));
            PERFORM fail_job(v_job_id);
            EXECUTE 'SELECT set_config(''search_path'','''||v_old_search_path||''',''false'')';
        END IF;
        RAISE EXCEPTION '%', SQLERRM;
END
$$;


/*
 * Function to create a child table in a time-based partition set
 */
CREATE OR REPLACE FUNCTION create_time_partition (p_parent_table text, p_control text, p_interval interval, p_datetime_string text, p_partition_times timestamp[]) RETURNS text
    LANGUAGE plpgsql SECURITY DEFINER
    AS $$
DECLARE

v_all                           text[] := ARRAY['SELECT', 'INSERT', 'UPDATE', 'DELETE', 'TRUNCATE', 'REFERENCES', 'TRIGGER'];
v_grantees                      text[];
v_job_id                        bigint;
v_jobmon_schema                 text;
v_old_search_path               text;
v_parent_grant                  record;
v_parent_owner                  text;
v_partition_name                text;
v_partition_timestamp_end       timestamp;
v_partition_timestamp_start     timestamp;
v_quarter                       text;
v_revoke                        text[];
v_step_id                       bigint;
v_tablename                     text;
v_trunc_value                   text;
v_time                          timestamp;
v_year                          text;

BEGIN

SELECT nspname INTO v_jobmon_schema FROM pg_namespace n, pg_extension e WHERE e.extname = 'pg_jobmon' AND e.extnamespace = n.oid;
IF v_jobmon_schema IS NOT NULL THEN
    SELECT current_setting('search_path') INTO v_old_search_path;
    EXECUTE 'SELECT set_config(''search_path'',''@extschema@,'||v_jobmon_schema||''',''false'')';
END IF;

SELECT tableowner INTO v_parent_owner FROM pg_tables WHERE schemaname ||'.'|| tablename = p_parent_table;

FOREACH v_time IN ARRAY p_partition_times LOOP

    v_partition_name := p_parent_table || '_p';

    IF p_interval = '1 year' OR p_interval = '1 month' OR p_interval = '1 day' OR p_interval = '1 hour' OR p_interval = '30 mins' OR p_interval = '15 mins' THEN
        v_partition_name := v_partition_name || to_char(v_time, 'YYYY');
        v_trunc_value := 'year';

        IF p_interval = '1 month' OR p_interval = '1 day' OR p_interval = '1 hour' OR p_interval = '30 mins' OR p_interval = '15 mins' THEN
            v_partition_name := v_partition_name || '_' || to_char(v_time, 'MM');
            v_trunc_value := 'month';

            IF p_interval = '1 day' OR p_interval = '1 hour' OR p_interval = '30 mins' OR p_interval = '15 mins' THEN
                v_partition_name := v_partition_name || '_' || to_char(v_time, 'DD');
                    v_trunc_value := 'day';

                IF p_interval = '1 hour' OR p_interval = '30 mins' OR p_interval = '15 mins' THEN
                    v_partition_name := v_partition_name || '_' || to_char(v_time, 'HH24');
                    IF p_interval <> '30 mins' AND p_interval <> '15 mins' THEN
                        v_partition_name := v_partition_name || '00';
                        v_trunc_value := 'hour';
                    ELSIF p_interval = '15 mins' THEN
                        IF date_part('minute', v_time) < 15 THEN
                            v_partition_name := v_partition_name || '00';
                        ELSIF date_part('minute', v_time) >= 15 AND date_part('minute', v_time) < 30 THEN
                            v_partition_name := v_partition_name || '15';
                        ELSIF date_part('minute', v_time) >= 30 AND date_part('minute', v_time) < 45 THEN
                            v_partition_name := v_partition_name || '30';
                        ELSE
                            v_partition_name := v_partition_name || '45';
                        END IF;
                        v_trunc_value := 'minute';
                    ELSIF p_interval = '30 mins' THEN
                        IF date_part('minute', v_time) < 30 THEN
                            v_partition_name := v_partition_name || '00';
                        ELSE
                            v_partition_name := v_partition_name || '30';
                        END IF;
                        v_trunc_value := 'minute';
                    END IF;
                END IF; -- end hour IF
            END IF; -- end day IF
        END IF; -- end month IF
    ELSIF p_interval = '1 week' THEN
        v_partition_name := v_partition_name || to_char(v_time, 'IYYY') || 'w' || to_char(v_time, 'IW');
        v_trunc_value := 'week';
    END IF; -- end year/week IF

    -- pull out datetime portion of last partition's tablename if it matched one of the above partitioning intervals
    IF v_trunc_value IS NOT NULL THEN
        v_partition_timestamp_start := date_trunc(v_trunc_value, to_timestamp(substring(v_partition_name from char_length(p_parent_table||'_p')+1), p_datetime_string));
        v_partition_timestamp_end := date_trunc(v_trunc_value, to_timestamp(substring(v_partition_name from char_length(p_parent_table||'_p')+1), p_datetime_string) + p_interval);
    END IF;

    -- "Q" is ignored in to_timestamp, so handle special case
    IF p_interval = '3 months' THEN
        v_year := to_char(v_time, 'YYYY');
        v_quarter := to_char(v_time, 'Q');
        v_partition_name := v_partition_name || v_year || 'q' || v_quarter;
        v_trunc_value := 'quarter';
        CASE
            WHEN v_quarter = '1' THEN
                v_partition_timestamp_start := date_trunc(v_trunc_value, to_timestamp(v_year || '-01-01', 'YYYY-MM-DD'));
            WHEN v_quarter = '2' THEN
                v_partition_timestamp_start := date_trunc(v_trunc_value, to_timestamp(v_year || '-04-01', 'YYYY-MM-DD'));
            WHEN v_quarter = '3' THEN
                v_partition_timestamp_start := date_trunc(v_trunc_value, to_timestamp(v_year || '-07-01', 'YYYY-MM-DD'));
            WHEN v_quarter = '4' THEN
                v_partition_timestamp_start := date_trunc(v_trunc_value, to_timestamp(v_year || '-10-01', 'YYYY-MM-DD'));
        END CASE;
        v_partition_timestamp_end := date_trunc(v_trunc_value, (v_partition_timestamp_start + p_interval));
    END IF;

    SELECT schemaname ||'.'|| tablename INTO v_tablename FROM pg_catalog.pg_tables WHERE schemaname ||'.'|| tablename = v_partition_name;
    IF v_tablename IS NOT NULL THEN
        CONTINUE;
    END IF;

    IF v_jobmon_schema IS NOT NULL THEN
        v_job_id := add_job('PARTMAN CREATE TABLE: '||p_parent_table);
        v_step_id := add_step(v_job_id, 'Creating new partition '||v_partition_name||' with interval from '||v_partition_timestamp_start||' to '||(v_partition_timestamp_end-'1sec'::interval));
    END IF;

    IF position('.' in p_parent_table) > 0 THEN
        v_tablename := substring(v_partition_name from position('.' in v_partition_name)+1);
    END IF;

    EXECUTE 'CREATE TABLE '||v_partition_name||' (LIKE '||p_parent_table||' INCLUDING DEFAULTS INCLUDING CONSTRAINTS INCLUDING INDEXES INCLUDING STORAGE INCLUDING COMMENTS)';
    EXECUTE 'ALTER TABLE '||v_partition_name||' ADD CONSTRAINT '||v_tablename||'_partition_check
        CHECK ('||p_control||'>='||quote_literal(v_partition_timestamp_start)||' AND '||p_control||'<'||quote_literal(v_partition_timestamp_end)||')';
    EXECUTE 'ALTER TABLE '||v_partition_name||' INHERIT '||p_parent_table;

    FOR v_parent_grant IN
        SELECT array_agg(DISTINCT privilege_type::text ORDER BY privilege_type::text) AS types, grantee
        FROM information_schema.table_privileges
        WHERE table_schema ||'.'|| table_name = p_parent_table
        GROUP BY grantee
    LOOP
        EXECUTE 'GRANT '||array_to_string(v_parent_grant.types, ',')||' ON '||v_partition_name||' TO '||v_parent_grant.grantee;
        SELECT array_agg(r) INTO v_revoke FROM (SELECT unnest(v_all) AS r EXCEPT SELECT unnest(v_parent_grant.types)) x;
        IF v_revoke IS NOT NULL THEN
            EXECUTE 'REVOKE '||array_to_string(v_revoke, ',')||' ON '||v_partition_name||' FROM '||v_parent_grant.grantee||' CASCADE';
        END IF;
        v_grantees := array_append(v_grantees, v_parent_grant.grantee::text);
    END LOOP;
    -- Revoke all privileges from roles that have none on the parent
    IF v_grantees IS NOT NULL THEN
        SELECT array_agg(r) INTO v_revoke FROM (
            SELECT DISTINCT grantee::text AS r FROM information_schema.table_privileges WHERE table_schema ||'.'|| table_name = v_partition_name
            EXCEPT
            SELECT unnest(v_grantees)) x;
        IF v_revoke IS NOT NULL THEN
            EXECUTE 'REVOKE ALL ON '||v_partition_name||' FROM '||array_to_string(v_revoke, ',');
        END IF;
    END IF;

    EXECUTE 'ALTER TABLE '||v_partition_name||' OWNER TO '||v_parent_owner;

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

END LOOP;

IF v_jobmon_schema IS NOT NULL THEN
    EXECUTE 'SELECT set_config(''search_path'','''||v_old_search_path||''',''false'')';
END IF;

RETURN v_partition_name;

EXCEPTION
    WHEN OTHERS THEN
        IF v_jobmon_schema IS NOT NULL THEN
            EXECUTE 'SELECT set_config(''search_path'',''@extschema@,'||v_jobmon_schema||''',''false'')';
            IF v_job_id IS NULL THEN
                v_job_id := add_job('PARTMAN CREATE TABLE: '||p_parent_table);
                v_step_id := add_step(v_job_id, 'Partition maintenance for table '||p_parent_table||' failed');
            ELSIF v_step_id IS NULL THEN
                v_step_id := add_step(v_job_id, 'EXCEPTION before first step logged');
            END IF;
            PERFORM update_step(v_step_id, 'CRITICAL', 'ERROR: '||coalesce(SQLERRM,'unknown'));
            PERFORM fail_job(v_job_id);
            EXECUTE 'SELECT set_config(''search_path'','''||v_old_search_path||''',''false'')';
        END IF;
        RAISE EXCEPTION '%', SQLERRM;
END
$$;


/*
 * Function to drop child tables from a time-based partition set.
 * Options to move table to different schema, drop only indexes or actually drop the table from the database.
 */
CREATE FUNCTION drop_partition_id(p_parent_table text, p_retention bigint DEFAULT NULL, p_keep_table boolean DEFAULT NULL, p_keep_index boolean DEFAULT NULL, p_retention_schema text DEFAULT NULL) RETURNS int
    LANGUAGE plpgsql SECURITY DEFINER
    AS $$
DECLARE

v_adv_lock                  boolean;
v_child_table               text;
v_control                   text;
v_drop_count                int := 0;
v_index                     record;
v_job_id                    bigint;
v_jobmon_schema             text;
v_max                       bigint;
v_old_search_path           text;
v_part_interval             bigint;
v_partition_id              bigint;
v_retention                 bigint;
v_retention_keep_index      boolean;
v_retention_keep_table      boolean;
v_retention_schema          text;
v_step_id                   bigint;

BEGIN

v_adv_lock := pg_try_advisory_lock(hashtext('pg_partman drop_partition_id'));
IF v_adv_lock = 'false' THEN
    RAISE NOTICE 'drop_partition_id already running.';
    RETURN 0;
END IF;

SELECT nspname INTO v_jobmon_schema FROM pg_namespace n, pg_extension e WHERE e.extname = 'pg_jobmon' AND e.extnamespace = n.oid;
IF v_jobmon_schema IS NOT NULL THEN
    SELECT current_setting('search_path') INTO v_old_search_path;
    EXECUTE 'SELECT set_config(''search_path'',''@extschema@,'||v_jobmon_schema||''',''false'')';
END IF;


-- Allow override of configuration options
IF p_retention IS NULL THEN
    SELECT
        part_interval::bigint
        , control
        , retention::bigint
        , retention_keep_table
        , retention_keep_index
        , retention_schema
    INTO
        v_part_interval
        , v_control
        , v_retention
        , v_retention_keep_table
        , v_retention_keep_index
        , v_retention_schema
    FROM @extschema@.part_config
    WHERE parent_table = p_parent_table
    AND (type = 'id-static' OR type = 'id-dynamic')
    AND retention IS NOT NULL;

    IF v_part_interval IS NULL THEN
        RAISE EXCEPTION 'Configuration for given parent table with a retention period not found: %', p_parent_table;
    END IF;
ELSE
     SELECT
        part_interval::bigint
        , control
        , retention_keep_table
        , retention_keep_index
        , retention_schema
    INTO
        v_part_interval
        , v_control
        , v_retention_keep_table
        , v_retention_keep_index
        , v_retention_schema
    FROM @extschema@.part_config
    WHERE parent_table = p_parent_table
    AND (type = 'id-static' OR type = 'id-dynamic');
    v_retention := p_retention;

    IF v_part_interval IS NULL THEN
        RAISE EXCEPTION 'Configuration for given parent table not found: %', p_parent_table;
    END IF;
END IF;

IF p_keep_table IS NOT NULL THEN
    v_retention_keep_table = p_keep_table;
END IF;
IF p_keep_index IS NOT NULL THEN
    v_retention_keep_index = p_keep_index;
END IF;
IF p_retention_schema IS NOT NULL THEN
    v_retention_schema = p_retention_schema;
END IF;

IF v_jobmon_schema IS NOT NULL THEN
    v_job_id := add_job('PARTMAN DROP ID PARTITION: '|| p_parent_table);
END IF;

EXECUTE 'SELECT max('||v_control||') FROM '||p_parent_table INTO v_max;

-- Loop through child tables of the given parent
FOR v_child_table IN
    SELECT n.nspname||'.'||c.relname FROM pg_inherits i join pg_class c ON i.inhrelid = c.oid join pg_namespace n ON c.relnamespace = n.oid WHERE i.inhparent::regclass = p_parent_table::regclass ORDER BY i.inhrelid ASC
LOOP
    v_partition_id := substring(v_child_table from char_length(p_parent_table||'_p')+1)::bigint;

    -- Add one interval since partition names contain the start of the constraint period
    IF v_retention <= (v_max - (v_partition_id + v_part_interval)) THEN
        IF v_jobmon_schema IS NOT NULL THEN
            v_step_id := add_step(v_job_id, 'Uninherit table '||v_child_table||' from '||p_parent_table);
        END IF;
        EXECUTE 'ALTER TABLE '||v_child_table||' NO INHERIT ' || p_parent_table;
        IF v_jobmon_schema IS NOT NULL THEN
            PERFORM update_step(v_step_id, 'OK', 'Done');
        END IF;
        IF v_retention_schema IS NULL THEN
            IF v_retention_keep_table = false THEN
                IF v_jobmon_schema IS NOT NULL THEN
                    v_step_id := add_step(v_job_id, 'Drop table '||v_child_table);
                END IF;
                EXECUTE 'DROP TABLE '||v_child_table;
                IF v_jobmon_schema IS NOT NULL THEN
                    PERFORM update_step(v_step_id, 'OK', 'Done');
                END IF;
            ELSIF v_retention_keep_index = false THEN
                FOR v_index IN
                    SELECT i.indexrelid::regclass AS name
                    , c.conname
                    FROM pg_catalog.pg_index i
                    LEFT JOIN pg_catalog.pg_constraint c ON i.indexrelid = c.conindid
                    WHERE i.indrelid = v_child_table::regclass
                LOOP
                    IF v_jobmon_schema IS NOT NULL THEN
                        v_step_id := add_step(v_job_id, 'Drop index '||v_index.name||' from '||v_child_table);
                    END IF;
                    IF v_index.conname IS NOT NULL THEN
                        EXECUTE 'ALTER TABLE '||v_child_table||' DROP CONSTRAINT '||v_index.conname;
                    ELSE
                        EXECUTE 'DROP INDEX '||v_index.name;
                    END IF;
                    IF v_jobmon_schema IS NOT NULL THEN
                        PERFORM update_step(v_step_id, 'OK', 'Done');
                    END IF;
                END LOOP;
            END IF;
        ELSE -- Move to new schema
            IF v_jobmon_schema IS NOT NULL THEN
                v_step_id := add_step(v_job_id, 'Moving table '||v_child_table||' to schema '||v_retention_schema);
            END IF;

            EXECUTE 'ALTER TABLE '||v_child_table||' SET SCHEMA '||v_retention_schema;

            IF v_jobmon_schema IS NOT NULL THEN
                PERFORM update_step(v_step_id, 'OK', 'Done');
            END IF;
        END IF; -- End retention schema if

        v_drop_count := v_drop_count + 1;
    END IF; -- End retention check IF

END LOOP; -- End child table loop

IF v_jobmon_schema IS NOT NULL THEN
    v_step_id := add_step(v_job_id, 'Finished partition drop maintenance');
    PERFORM update_step(v_step_id, 'OK', v_drop_count||' partitions dropped.');
    PERFORM close_job(v_job_id);
    EXECUTE 'SELECT set_config(''search_path'','''||v_old_search_path||''',''false'')';
END IF;

PERFORM pg_advisory_unlock(hashtext('pg_partman drop_partition_id'));

RETURN v_drop_count;

EXCEPTION
    WHEN QUERY_CANCELED THEN
        PERFORM pg_advisory_unlock(hashtext('pg_partman drop_partition_id'));
        RAISE EXCEPTION '%', SQLERRM;
    WHEN OTHERS THEN
        IF v_jobmon_schema IS NOT NULL THEN
            EXECUTE 'SELECT set_config(''search_path'',''@extschema@,'||v_jobmon_schema||''',''false'')';
            IF v_job_id IS NULL THEN
                v_job_id := add_job('PARTMAN DROP ID PARTITION');
                v_step_id := add_step(v_job_id, 'EXCEPTION before job logging started');
            END IF;
            IF v_step_id IS NULL THEN
                v_step_id := add_step(v_job_id, 'EXCEPTION before first step logged');
            END IF;
            PERFORM update_step(v_step_id, 'CRITICAL', 'ERROR: '||coalesce(SQLERRM,'unknown'));
            PERFORM fail_job(v_job_id);
            EXECUTE 'SELECT set_config(''search_path'','''||v_old_search_path||''',''false'')';
        END IF;
        PERFORM pg_advisory_unlock(hashtext('pg_partman drop_partition_id'));
        RAISE EXCEPTION '%', SQLERRM;
END
$$;


/*
 * Function to drop child tables from a time-based partition set.
 * Options to move table to different schema, drop only indexes or actually drop the table from the database.
 */
CREATE FUNCTION drop_partition_time(p_parent_table text, p_retention interval DEFAULT NULL, p_keep_table boolean DEFAULT NULL, p_keep_index boolean DEFAULT NULL, p_retention_schema text DEFAULT NULL) RETURNS int
    LANGUAGE plpgsql SECURITY DEFINER
    AS $$
DECLARE

v_adv_lock                  boolean;
v_child_table               text;
v_datetime_string           text;
v_drop_count                int := 0;
v_index                     record;
v_job_id                    bigint;
v_jobmon_schema             text;
v_old_search_path           text;
v_part_interval             interval;
v_partition_timestamp       timestamp;
v_quarter                   text;
v_retention                 interval;
v_retention_keep_index      boolean;
v_retention_keep_table      boolean;
v_retention_schema          text;
v_step_id                   bigint;
v_year                      text;

BEGIN

v_adv_lock := pg_try_advisory_lock(hashtext('pg_partman drop_partition_time'));
IF v_adv_lock = 'false' THEN
    RAISE NOTICE 'drop_partition_time already running.';
    RETURN 0;
END IF;

SELECT nspname INTO v_jobmon_schema FROM pg_namespace n, pg_extension e WHERE e.extname = 'pg_jobmon' AND e.extnamespace = n.oid;
IF v_jobmon_schema IS NOT NULL THEN
    SELECT current_setting('search_path') INTO v_old_search_path;
    EXECUTE 'SELECT set_config(''search_path'',''@extschema@,'||v_jobmon_schema||''',''false'')';
END IF;

-- Allow override of configuration options
IF p_retention IS NULL THEN
    SELECT
        part_interval::interval
        , retention::interval
        , retention_keep_table
        , retention_keep_index
        , datetime_string
        , retention_schema
    INTO
        v_part_interval
        , v_retention
        , v_retention_keep_table
        , v_retention_keep_index
        , v_datetime_string
        , v_retention_schema
    FROM @extschema@.part_config
    WHERE parent_table = p_parent_table
    AND (type = 'time-static' OR type = 'time-dynamic')
    AND retention IS NOT NULL;

    IF v_part_interval IS NULL THEN
        RAISE EXCEPTION 'Configuration for given parent table with a retention period not found: %', p_parent_table;
    END IF;
ELSE
    SELECT
        part_interval::interval
        , retention_keep_table
        , retention_keep_index
        , datetime_string
        , retention_schema
    INTO
        v_part_interval
        , v_retention_keep_table
        , v_retention_keep_index
        , v_datetime_string
        , v_retention_schema
    FROM @extschema@.part_config
    WHERE parent_table = p_parent_table
    AND (type = 'time-static' OR type = 'time-dynamic');
    v_retention := p_retention;

    IF v_part_interval IS NULL THEN
        RAISE EXCEPTION 'Configuration for given parent table not found: %', p_parent_table;
    END IF;
END IF;

IF p_keep_table IS NOT NULL THEN
    v_retention_keep_table = p_keep_table;
END IF;
IF p_keep_index IS NOT NULL THEN
    v_retention_keep_index = p_keep_index;
END IF;
IF p_retention_schema IS NOT NULL THEN
    v_retention_schema = p_retention_schema;
END IF;

IF v_jobmon_schema IS NOT NULL THEN
    v_job_id := add_job('PARTMAN DROP TIME PARTITION: '|| p_parent_table);
END IF;

-- Loop through child tables of the given parent
FOR v_child_table IN
    SELECT n.nspname||'.'||c.relname FROM pg_inherits i join pg_class c ON i.inhrelid = c.oid join pg_namespace n ON c.relnamespace = n.oid WHERE i.inhparent::regclass = p_parent_table::regclass ORDER BY i.inhrelid ASC
LOOP
    -- pull out datetime portion of last partition's tablename to make the next one
    IF v_part_interval != '3 months' THEN
        v_partition_timestamp := to_timestamp(substring(v_child_table from char_length(p_parent_table||'_p')+1), v_datetime_string);
    ELSE
        -- to_timestamp doesn't recognize 'Q' date string formater. Handle it
        v_year := split_part(substring(v_child_table from char_length(p_parent_table||'_p')+1), 'q', 1);
        v_quarter := split_part(substring(v_child_table from char_length(p_parent_table||'_p')+1), 'q', 2);
        CASE
            WHEN v_quarter = '1' THEN
                v_partition_timestamp := to_timestamp(v_year || '-01-01', 'YYYY-MM-DD');
            WHEN v_quarter = '2' THEN
                v_partition_timestamp := to_timestamp(v_year || '-04-01', 'YYYY-MM-DD');
            WHEN v_quarter = '3' THEN
                v_partition_timestamp := to_timestamp(v_year || '-07-01', 'YYYY-MM-DD');
            WHEN v_quarter = '4' THEN
                v_partition_timestamp := to_timestamp(v_year || '-10-01', 'YYYY-MM-DD');
        END CASE;
    END IF;

    -- Add one interval since partition names contain the start of the constraint period
    IF v_retention < (CURRENT_TIMESTAMP - (v_partition_timestamp + v_part_interval)) THEN
        IF v_jobmon_schema IS NOT NULL THEN
            v_step_id := add_step(v_job_id, 'Uninherit table '||v_child_table||' from '||p_parent_table);
        END IF;
        EXECUTE 'ALTER TABLE '||v_child_table||' NO INHERIT ' || p_parent_table;
        IF v_jobmon_schema IS NOT NULL THEN
            PERFORM update_step(v_step_id, 'OK', 'Done');
        END IF;
        IF v_retention_schema IS NULL THEN
            IF v_retention_keep_table = false THEN
                IF v_jobmon_schema IS NOT NULL THEN
                    v_step_id := add_step(v_job_id, 'Drop table '||v_child_table);
                END IF;
                EXECUTE 'DROP TABLE '||v_child_table;
                IF v_jobmon_schema IS NOT NULL THEN
                    PERFORM update_step(v_step_id, 'OK', 'Done');
                END IF;
            ELSIF v_retention_keep_index = false THEN
                FOR v_index IN
                    SELECT i.indexrelid::regclass AS name
                    , c.conname
                    FROM pg_catalog.pg_index i
                    LEFT JOIN pg_catalog.pg_constraint c ON i.indexrelid = c.conindid
                    WHERE i.indrelid = v_child_table::regclass
                LOOP
                    IF v_jobmon_schema IS NOT NULL THEN
                        v_step_id := add_step(v_job_id, 'Drop index '||v_index.name||' from '||v_child_table);
                    END IF;
                    IF v_index.conname IS NOT NULL THEN
                        EXECUTE 'ALTER TABLE '||v_child_table||' DROP CONSTRAINT '||v_index.conname;
                    ELSE
                        EXECUTE 'DROP INDEX '||v_index.name;
                    END IF;
                    IF v_jobmon_schema IS NOT NULL THEN
                        PERFORM update_step(v_step_id, 'OK', 'Done');
                    END IF;
                END LOOP;
            END IF;
        ELSE -- Move to new schema
            IF v_jobmon_schema IS NOT NULL THEN
                v_step_id := add_step(v_job_id, 'Moving table '||v_child_table||' to schema '||v_retention_schema);
            END IF;

            EXECUTE 'ALTER TABLE '||v_child_table||' SET SCHEMA '||v_retention_schema;

            IF v_jobmon_schema IS NOT NULL THEN
                PERFORM update_step(v_step_id, 'OK', 'Done');
            END IF;
        END IF; -- End retention schema if

        v_drop_count := v_drop_count + 1;
    END IF; -- End retention check IF

END LOOP; -- End child table loop

IF v_jobmon_schema IS NOT NULL THEN
    v_step_id := add_step(v_job_id, 'Finished partition drop maintenance');
    PERFORM update_step(v_step_id, 'OK', v_drop_count||' partitions dropped.');
    PERFORM close_job(v_job_id);
    EXECUTE 'SELECT set_config(''search_path'','''||v_old_search_path||''',''false'')';
END IF;

PERFORM pg_advisory_unlock(hashtext('pg_partman drop_partition_time'));

RETURN v_drop_count;

EXCEPTION
    WHEN QUERY_CANCELED THEN
        PERFORM pg_advisory_unlock(hashtext('pg_partman drop_partition_time'));
        RAISE EXCEPTION '%', SQLERRM;
    WHEN OTHERS THEN
        IF v_jobmon_schema IS NOT NULL THEN
            EXECUTE 'SELECT set_config(''search_path'',''@extschema@,'||v_jobmon_schema||''',''false'')';
            IF v_job_id IS NULL THEN
                v_job_id := add_job('PARTMAN DROP TIME PARTITION');
                v_step_id := add_step(v_job_id, 'EXCEPTION before job logging started');
            END IF;
            IF v_step_id IS NULL THEN
                v_step_id := add_step(v_job_id, 'EXCEPTION before first step logged');
            END IF;
            PERFORM update_step(v_step_id, 'CRITICAL', 'ERROR: '||coalesce(SQLERRM,'unknown'));
            PERFORM fail_job(v_job_id);
            EXECUTE 'SELECT set_config(''search_path'','''||v_old_search_path||''',''false'')';
        END IF;
        PERFORM pg_advisory_unlock(hashtext('pg_partman drop_partition_time'));
        RAISE EXCEPTION '%', SQLERRM;
END
$$;


-- Restore original privileges to objects that were dropped
SELECT @extschema@.replay_preserved_privs();
DROP FUNCTION @extschema@.replay_preserved_privs();
DROP TABLE pg_partman_preserve_privs_temp;
