repro.py

import argparse
import MySQLdb
import time


def main():
    parser = argparse.ArgumentParser()
    args = parser.parse_args()

    conn = MySQLdb.connect(db='ghtest')
    cursor = conn.cursor()
    cursor.execute('DROP TABLE IF EXISTS ghtest')
    cursor.execute('DROP TABLE IF EXISTS _ghtest_gho')
    cursor.execute('DROP TABLE IF EXISTS _ghtest_del')
    cursor.execute('CREATE TABLE ghtest (id BIGINT AUTO_INCREMENT PRIMARY KEY, to_drop INT DEFAULT NULL, value MEDIUMTEXT DEFAULT NULL, other_field BOOLEAN DEFAULT FALSE, always_null INT DEFAULT NULL)')
    for i in range(102400):
        cursor.execute('INSERT INTO ghtest(value) VALUES(%s)', (str(i),))
    print('created, will do insertions and updates for next 30s')
    start = time.time()
    while time.time() - start < 30:
        conn.begin()
        cursor.execute('INSERT INTO ghtest(value, other_field) VALUES (%s, %s)', (str(i), False))
        pk = cursor.lastrowid
        conn.commit()
        conn.begin()
        cursor.execute('UPDATE ghtest SET other_field=%s WHERE id=%s', (True, pk))
        conn.commit()
    print('done')


main()