❓ 在使用 mycat 登陆之后，使用 use 切换数据库很慢，查询表会报错

• 开始 schema.xml 配置如下

<?xml version="1.0"?>
<!DOCTYPE mycat:schema SYSTEM "schema.dtd">
<mycat:schema xmlns:mycat="http://io.mycat/">

        <schema name="demo" checkSQLschema="true" sqlMaxLimit="100">
                <table name="tb_student" dataNode="dn1,dn2" rule="auto-sharding-long" />
        </schema>
        <dataNode name="dn1" dataHost="dhost1" database="demo" />
        <dataNode name="dn2" dataHost="dhost2" database="demo" />

        <dataHost name="dhost1" maxCon="1000" minCon="10" balance="0"
                          writeType="0" dbType="mysql" dbDriver="native" switchType="1"  slaveThreshold="100">
                <heartbeat>select user()</heartbeat>

                <writeHost host="master" url="192.168.169.150:3306" user="root"  password="Abcd@1234" />
        </dataHost>

        <dataHost name="dhost2" maxCon="1000" minCon="10" balance="0"
                          writeType="0" dbType="mysql" dbDriver="native" switchType="1"  slaveThreshold="100">
                <heartbeat>select user()</heartbeat>

                <writeHost host="master" url="192.168.169.151:3306" user="root"  password="Abcd@1234" />
        </dataHost>

</mycat:schema>

👉 将安装 mycat 节点的地址改为 127.0.0.1 之后访问就正常了

<dataHost name="dhost1" maxCon="1000" minCon="10" balance="0"
                          writeType="0" dbType="mysql" dbDriver="native" switchType="1"  slaveThreshold="100">
                <heartbeat>select user()</heartbeat>

                <writeHost host="master" url="127.0.0.1:3306" user="root"  password="Abcd@1234" />
        </dataHost>

        <dataHost name="dhost2" maxCon="1000" minCon="10" balance="0"
                          writeType="0" dbType="mysql" dbDriver="native" switchType="1"  slaveThreshold="100">
                <heartbeat>select user()</heartbeat>

                <writeHost host="master" url="192.168.169.151:3306" user="root"  password="Abcd@1234" />
        </dataHost>