gistfile1.txt

MariaDB [j2]> explain format=json select * from t10 join (select t11.a, 12.b from t11, t12 limit 10) T\G
*************************** 1. row ***************************
EXPLAIN: {
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "t10",
      "access_type": "ALL",
      "rows": 1,
      "filtered": 100
    },
    "block-nl-join": {
      "table": {
        "table_name": "<derived2>",
        "access_type": "ALL",
        "rows": 2,
        "filtered": 100
      },
      "buffer_type": "flat",
      "buffer_size": "173",
      "join_type": "BNL",
      "materialized": {
        "query_block": {
          "select_id": 2,
          "table": {
            "table_name": "t11",
            "access_type": "ALL",
            "rows": 1,
            "filtered": 100
          },
          "block-nl-join": {
            "table": {
              "table_name": "t12",
              "access_type": "ALL",
              "rows": 1,
              "filtered": 100
            },
            "buffer_type": "flat",
            "buffer_size": "65",
            "join_type": "BNL"
          }
        }
      }
    }
  }
}
1 row in set (0.002 sec)