I'm using 5.6 MySQL database to insert tens of millions records between multiple tables.

Before the insertion I send all my data into a temp memory table, for that reason I have increased both `tmp_table_size` and `max_heap_table_size` to 15GB. 

It works well so far, but after I explicitly drop the temp table and after my connection is closed MySQL keeps using the memory allocated for the temp table and the only way I'm able to free that memory is to restart the service. 

My application runs every few hours and I eventually run out of memory after 2-3 runs. Is there another way to fix this without restarting the service?


UPD: here's the structure of the temp table:

**Temp table DDL**
```
CREATE TEMPORARY TABLE ids_temp (
  AAID binary(16) NOT NULL,
  GroupID int(10) NOT NULL,
  INDEX temp_GroupID_idx (GroupID)
) ENGINE = MEMORY
```

**Inserts into the temp table** (using [MySQLCursor.executemany()][1])
```
INSERT INTO ids_temp (ID, GroupID) VALUES (%s, %s)
```

**Drop statement**
```
DROP TEMPORARY TABLE IF EXISTS ids_temp
```

**Inserts to other tables**
```
INSERT IGNORE INTO data.{GroupID} (`ID`)
SELECT T.ID
FROM ids_temp T WHERE T.GroupID = {GroupId}
```


  [1]: https://dev.mysql.com/doc/connector-python/en/connector-python-api-mysqlcursor-executemany.html