# Suboptimal Sql Statement Execution Plan (Continue...)

+ Data in tables a and b were scanned on the TiKV side, where 146 million rows `TableScan_16`  were scanned

```6
+----------------------------+--------------+------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| id                         | count        | task | operator info                                                                                                                                                     |
+----------------------------+--------------+------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| StreamAgg_13               | 1.00         | root | funcs:count(1)                                                                                                                                                    |
| └─HashRightJoin_27         | 421.12       | root | inner join, inner:TableReader_18, equal:[eq(a.fund_code, b.fund_code)]                                                                                            |
|   ├─TableReader_18         | 421.12       | root | data:Selection_17                                                                                                                                                 |
|   │ └─Selection_17         | 421.12       | cop  | eq(a.pay_confirm_status, 1), eq(a.status, "CANCEL_SUCCESS"), gt(a.updated_at, 2020-03-03 22:31:08), in(a.type, "PURCHASE", "APPLY"), not(isnull(a.cancel_app_no)) |
|   │   └─TableScan_16       | 145920790.55 | cop  | table:a, range:[177045000,+inf], keep order:false                                                                                                                 |
|   └─TableReader_37         | 6442.00      | root | data:TableScan_36                                                                                                                                                 |
|     └─TableScan_36         | 6442.00      | cop  | table:b, range:[-inf,+inf], keep order:false                                                                                                                      |
+----------------------------+--------------+------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------+
```

------------------------------------------------------------
```
mysql> explain 
    -> select count(*)
    -> from tods.bus_jijin_trade_record a,   tods.bus_jijin_info b 
    -> where a.fund_code=b.fund_code  and a.type in ('PURCHASE','APPLY')  
    -> and a.status='CANCEL_SUCCESS' and   a.pay_confirm_status = 1 
    -> and a.cancel_app_no is not null and   a.id >=  177045000  
    -> and a.updated_at >   date_sub(now(), interval 48 hour) ;
+----------------------------+--------------+------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| id                         | count        | task | operator info                                                                                                                                                     |
+----------------------------+--------------+------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| StreamAgg_13               | 1.00         | root | funcs:count(1)                                                                                                                                                    |
| └─HashRightJoin_27         | 421.12       | root | inner join, inner:TableReader_18, equal:[eq(a.fund_code, b.fund_code)]                                                                                            |
|   ├─TableReader_18         | 421.12       | root | data:Selection_17                                                                                                                                                 |
|   │ └─Selection_17         | 421.12       | cop  | eq(a.pay_confirm_status, 1), eq(a.status, "CANCEL_SUCCESS"), gt(a.updated_at, 2020-03-03 22:31:08), in(a.type, "PURCHASE", "APPLY"), not(isnull(a.cancel_app_no)) |
|   │   └─TableScan_16       | 145920790.55 | cop  | table:a, range:[177045000,+inf], keep order:false                                                                                                                 |
|   └─TableReader_37         | 6442.00      | root | data:TableScan_36                                                                                                                                                 |
|     └─TableScan_36         | 6442.00      | cop  | table:b, range:[-inf,+inf], keep order:false                                                                                                                      |
+----------------------------+--------------+------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------+
```

In a query like this, there may be cases where the execution plan is inaccurate, such as the execution plan of this query.
TableScan_16, TableScan_36: Indicates that the data of tables a and b were scanned on the TiKV side respectively, where TableScan_16 scanned 146 million rows;
Selection_17: Indicates data that satisfies the where condition after table a;
TableReader_37: Since table b does not have independent additional conditions, this part of the data is directly return to TiDB;
TableReader_18: return the results of each coprocessor that satisfies the A table condition to TiDB;
HashRightJoin_27: hash join the results on TableReader_37 and TableReader_18;
StreamAgGG_13: Further count all rows and return the data to the client;