CREATE OR REPLACE FUNCTION populate_pg_stat_statements_current(interval_label TEXT DEFAULT '1m')
RETURNS void AS $$
DECLARE
    prev_table TEXT := 'pgss_prev_' || interval_label;
    result_table TEXT := 'pgss_cur_' || interval_label;
    dynamic_sql TEXT;
BEGIN

    dynamic_sql := format($fmt$
        TRUNCATE TABLE %I; -- current

        WITH current AS (
            SELECT dbid, userid, queryid, query, calls, total_exec_time
            FROM pg_stat_statements
            WHERE query NOT ILIKE '%%pg_stat_statements%%' 
              AND query NOT ILIKE 'CREATE TABLE IF NOT EXISTS %%' 
              AND calls > 0
        ),
        diff AS (
            SELECT
                curr.query,
                curr.calls - COALESCE(prev.calls, 0) AS delta_calls,
                curr.total_exec_time - COALESCE(prev.total_exec_time, 0) AS delta_time,
                ROUND((
                    (curr.total_exec_time - COALESCE(prev.total_exec_time, 0)) /
                    NULLIF(curr.calls - COALESCE(prev.calls, 0), 0)
                )::NUMERIC, 3) AS avg_time
            FROM current curr
            LEFT JOIN %I prev 
              ON curr.dbid = prev.dbid 
             AND curr.queryid = prev.queryid
             AND curr.userid = prev.userid
            WHERE curr.calls - COALESCE(prev.calls, 0) > 0
        )
        INSERT INTO %I(query, delta_calls, delta_time, avg_time)
        SELECT query, delta_calls, delta_time, avg_time
        FROM diff
        ORDER BY delta_time DESC
        LIMIT 15;

        TRUNCATE TABLE %I; -- previous

        INSERT INTO %I(dbid, userid, queryid, query, calls, total_exec_time)
        SELECT DISTINCT ON (pss.dbid, pss.userid, pss.queryid)
               pss.dbid, pss.userid, pss.queryid, pss.query, pss.calls, pss.total_exec_time
        FROM pg_stat_statements pss
        WHERE pss.query NOT ILIKE '%%pg_stat_statements%%'
          AND pss.query NOT ILIKE 'CREATE TABLE IF NOT EXISTS %%'
          AND pss.calls > 0
        ORDER BY pss.dbid, pss.userid, pss.queryid, pss.total_exec_time DESC
        ON CONFLICT (dbid, userid, queryid) DO UPDATE
        SET query = EXCLUDED.query,
            calls = EXCLUDED.calls,
            total_exec_time = EXCLUDED.total_exec_time;
    $fmt$, result_table, prev_table, result_table, prev_table, prev_table);


    EXECUTE dynamic_sql;
END;
$$ LANGUAGE plpgsql;