OA系统冗余数据过多，访问效率受到影响，现需要对历史数据进行一次清理，以提高OA访问速度
大的数据主要体现在流程上，流程数据主要放在flow_run,flow_run_data,flow_run_prcs,flow_run_feedback表中，清理一年半以前的数据是比较合理的。run_id是主键而run_id随着时间的增加而变大，run_id小于50W的流程刚好是一年半以前的历史数据，选择run_id小于50W作为临界点进行删除。以下是清理数据的计划
思路：
①创建和flow_run_data、flow_run、flow_run_prcs、flow_run_feedback、notify表结构一致的表
②把需要清理的历史数据插入刚创建的备份表中
③删除正式表中的数据
操作：
1.晚上10点以后停止mysql数据库服务，前端web服务(避免有人继续访问)
2.备份td_oa数据库
3.依次执行以下SQL语句：
4.开启web和mysql服务，验证是否成功
//对flow_run的操作
create table flow_run_old like flow_run;
insert into flow_run_old select * from flow_run where run_id < '500000';
delete from flow_run where run_id < '500000';
//对flow_run_data的操作
create table flow_run_data_old like flow_run_data;
insert flow_run_data_old select * from flow_run_data where run_id < '500000'
delete from flow_run_data where run_id < '500000';
//对flow_run_prcs操作
create table flow_run_prcs_old like flow_run_prcs;
insert into flow_run_prcs_old select * from flow_run_prcs where run_id < '500000'
delete from flow_run_prcs where run_id < '500000';
select count(*) from flow_run_prcs_old
//对flow_run_feedback操作
create table flow_run_feedback_old like flow_run_feedback;
insert into flow_run_feedback_old select * from flow_run_feedback where run_id < '500000'
delete from flow_run_feedback where run_id < '500000';
//公告notify_id<3349是2013年以前的数据，从该时刻开始删除
create table notify_old like notify;
insert into notify_old select * from notify where notify_id < '3349';
delete from notify where notify_id < '3349';
//删除一年以前的系统日志sys_log、流程日志FLOW_RUN_LOG、SMS、SMS_BODY、UC_PMS、
delete from sys_log where time<date_sub(date(now()),interval 1 year);
//对流程日志的操作
create table flow_run_log_old like flow_run_log;
insert into flow_run_log_old select * from flow_run_log where run_id < '500000';
delete from flow_run_log where run_id < '500000';
=============================================================================================================
//会议室申请
create table meeting_old like meeting;
insert into meeting_old select * from meeting where m_request_time < '2013-06-01 00:00:00';
delete from meeting where m_request_time < '2013-06-01 00:00:00';
//车辆申请
create table vehicle_usage_old like vehicle_usage;
insert into vehicle_usage_old select * from vehicle_usage where vu_request_date < '2013-06-01 00:00:00';
delete from vehicle_usage where vu_request_date < '2013-06-01 00:00:00';
=============================================================================================================
//在线考试信息清理主要是exam_flow和exam_data两张表，这两张表是通过flow_id关联，清理2012-06-01以前的数据，flow_id<4212
//考试发布表exam_flow
create table exam_flow_old like exam_flow;
insert into exam_flow_old select * from exam_flow where flow_id<'4212';
delete from exam_flow where flow_id<'4212';
//考试信息表exam_data
create table exam_data_old like exam_data;
insert into exam_data_old select * from exam_data where flow_id<'4212';
delete from exam_data where flow_id<'4212';