摘要:

对Q17慢SQL进行分析

SQL分析:

SQL:

/stonedb57/install/bin/mysql -D tpch -e " 
        select
            sum(l_extendedprice) / 7.0 as avg_yearly
        from
            lineitem,
            part
        where
            p_partkey = l_partkey
            and p_brand = 'Brand#23'
            and p_container = 'MED BOX'
            and l_quantity < (
                select
                    0.2 * avg(l_quantity)
                from
                    lineitem
                where
                    l_partkey = p_partkey
            );
    "

explain分析:

*************************** 1. row ***************************
           id: 1
  select_type: PRIMARY
        table: lineitem
   partitions: NULL
         type: ALL
possible_keys: NULL