关于 mysql-connector- Java 在执行 insert 跟 update 之前都要去读取一下数据库是否 read only 这合理吗? - V2EX
0576coder
V2EX    Java

关于 mysql-connector- Java 在执行 insert 跟 update 之前都要去读取一下数据库是否 read only 这合理吗?

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  •   0576coder Jun 28, 2021 1874 views
    This topic created in 1780 days ago, the information mentioned may be changed or developed.

    版本

    mysql-connector-java 8.0.x

    问题 执行 insert 或者 update 的时候都回去判断数据库是否只读,手动查看源码在这里

    这里就是判断了数据库版本版本 然后根据版本不同去

    select @@session.tx_read_only

    select @@session.transaction_read_only

    虽然这样做很严谨 但是我感觉读写分离之类的应该在数据库中间件或者手动指定库来区别,为什么要多次一举这么设计

    4 replies    2021-06-29 02:29:23 +08:00
    nullcoder
        1
    nullcoder  
       Jun 28, 2021 via Android
    很合理,他有它的道理
    nullcoder
        2
    nullcoder  
       Jun 28, 2021 via Android
    但我可能解释不好
    0576coder
        3
    0576coder  
    OP
       Jun 29, 2021
    @nullcoder

    为啥 这样还多了一次查询- - 虽然可以通过 useLocalSessionState 设为 true 让他不走这段逻辑
    akira
        4
    akira  
       Jun 29, 2021   1
    你是否有考虑过,用户的环境可能性有多少 稀奇古怪的情况
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