================================================================
|ID|OPERATOR               |NAME         |EST.ROWS|EST.TIME(us)|
----------------------------------------------------------------
|0 |SCALAR GROUP BY        |             |1       |6532        |
|1 |弩岸SUBPLAN SCAN         |t            |2764    |6482        |
|2 |  弩岸RECURSIVE UNION ALL|             |2764    |6475        |
|3 |    念岸TABLE FULL SCAN  |tbl_districts|84      |695         |
|4 |    弩岸HASH JOIN        |             |2680    |5773        |
|5 |      念岸TABLE FULL SCAN|t            |199     |1           |
|6 |      弩岸TABLE FULL SCAN|m            |16780   |1055        |
================================================================
Outputs & filters:
-------------------------------------
  0 - output([T_FUN_COUNT(*)(0x7f21b049d090)]), filter(nil), rowset=256
      group(nil), agg_func([T_FUN_COUNT(*)(0x7f21b049d090)])
  1 - output(nil), filter(nil), rowset=256
      access(nil)
  2 - output([UNION([1])(0x7f21b04841c0)], [UNION([2])(0x7f21b0484410)], [UNION([3])(0x7f21b0484660)], [UNION([4])(0x7f21b04848b0)]), filter(nil), rowset=256
  3 - output([tbl_districts.districts_id(0x7f21b0449260)], [tbl_districts.parent_id(0x7f21b044b4b0)], [tbl_districts.districts_name(0x7f21b044bab0)], [1]), filter([cast(tbl_districts.districts_id(0x7f2
      1b0449260), DECIMAL(-1, -1))(0x7f21b04497d0) = cast(22, DECIMAL(2, 0))(0x7f21b044a320)(0x7f21b0448b10)]), rowset=256
      access([tbl_districts.districts_id(0x7f21b0449260)], [tbl_districts.parent_id(0x7f21b044b4b0)], [tbl_districts.districts_name(0x7f21b044bab0)]), partitions(p0)
      is_index_back=false, is_global_index=false, filter_before_indexback[false], 
      range_key([tbl_districts.districts_id(0x7f21b0449260)]), range(MIN ; MAX)always true
  4 - output([column_conv(VARCHAR,utf8mb4_general_ci,length:50,NULL,m.districts_id(0x7f21b04657c0))(0x7f21b04674c0)], [column_conv(VARCHAR,utf8mb4_general_ci,
      length:100,NULL,m.parent_id(0x7f21b04639e0))(0x7f21b046e7e0)], [column_conv(VARCHAR,utf8mb4_general_ci,length:150,NULL,m.districts_name(0x7f21b04660e0))(0x7f21b0475b00)],
       [column_conv(BIGINT,PS:(1,0),NULL,t.n(0x7f21b0464f30) + 1(0x7f21b0466950))(0x7f21b047ce20)]), filter(nil), rowset=256
      equal_conds([m.parent_id(0x7f21b04639e0) = t.districts_id(0x7f21b0463cd0)(0x7f21b0463290)]), other_conds(nil)
  5 - output([t.districts_id(0x7f21b0463cd0)], [t.n(0x7f21b0464f30)]), filter([t.n(0x7f21b0464f30) <= 20(0x7f21b04647e0)]), rowset=256
      access([t.districts_id(0x7f21b0463cd0)], [t.n(0x7f21b0464f30)])
      is_index_back=false, is_global_index=false, filter_before_indexback[false], 
      range_key(nil), range(MIN ; MAX)
  6 - output([m.districts_id(0x7f21b04657c0)], [m.parent_id(0x7f21b04639e0)], [m.districts_name(0x7f21b04660e0)]), filter(nil), rowset=256
      access([m.districts_id(0x7f21b04657c0)], [m.parent_id(0x7f21b04639e0)], [m.districts_name(0x7f21b04660e0)]), partitions(p0)
      is_index_back=false, is_global_index=false, 
      range_key([m.districts_id(0x7f21b04657c0)]), range(MIN ; MAX)always true
Used Hint:
-------------------------------------
  /*+
      
  */
Qb name trace:
-------------------------------------
  stmt_id:0, stmt_type:T_EXPLAIN 
  stmt_id:1, SEL$1
  stmt_id:2, SET$1 > SET$CEB121DD
  stmt_id:3, SEL$2 > SEL$A3D39CCF
  stmt_id:4, SEL$3 > SEL$B0E633B8
Outline Data: 
-------------------------------------
  /*+
      BEGIN_OUTLINE_DATA
      FULL(@"SEL$A3D39CCF" "jlsmz"."tbl_districts"@"SEL$2")
      LEADING(@"SEL$B0E633B8" ("t"@"SEL$3" "jlsmz"."m"@"SEL$3"))
      USE_HASH(@"SEL$B0E633B8" "jlsmz"."m"@"SEL$3")
      FULL(@"SEL$B0E633B8" "t"@"SEL$3")
      FULL(@"SEL$B0E633B8" "m"@"SEL$3")
      SIMPLIFY_EXPR(@"SEL$2")
      INLINE(@"SET$1")
      OUTER_TO_INNER(@"SEL$3")
      OPTIMIZER_FEATURES_ENABLE('4.2.1.0')
      END_OUTLINE_DATA
  */
Optimization Info:
-------------------------------------
  tbl_districts:
      table_rows:16780
      physical_range_rows:16780
      logical_range_rows:16780
      index_back_rows:0
      output_rows:83
      table_dop:1
      dop_method:Table DOP
      avaiable_index_name:[tbl_districts_districts_id_IDX, tbl_districts_districts_idp_IDX, tbl_districts]
      stats version:1710626401441251
      dynamic sampling level:0
      
  m:
      table_rows:16780
      physical_range_rows:16780
      logical_range_rows:16780
      index_back_rows:0
      output_rows:16780
      table_dop:1
      dop_method:Table DOP
      avaiable_index_name:[tbl_districts_districts_id_IDX, tbl_districts_districts_idp_IDX, tbl_districts]
      pruned_index_name:[tbl_districts_districts_id_IDX, tbl_districts_districts_idp_IDX]
      stats version:1710626401441251
      dynamic sampling level:0
  Plan Type:
      LOCAL
  Note:
      Degree of Parallelisim is 1 because of table property
  Expr Constraints:
      1 = 1 result is TRUE