Derby.log 输出文件未正确填充

Derby.log output file does not get populated correctly

我正在尝试查看由我的数据库生成的查询计划,但是 derby.log 没有填充查询信息。它包含如下内容:

我正在使用以下内容尝试填充它:

CallableStatement queryPlan = conn.prepareCall
    ("CALL SYSCS_UTIL.SYSCS_SET_DATABASE_PROPERTY(?,?)");
queryPlan.setString(1,"derby.language.logQueryPlan");
queryPlan.setString(2,"true");
queryPlan.execute();
queryPlan.close();

德比参考手册说 derby.language.logQueryPlan:

This property is static; if you change it while Derby is running, the change does not take effect until you reboot.

所以当您启动 Derby 时,您确实打算将其设置为 derby.properties 或命令行。