postgres 使用存储过程批量插入数据的操作

Z时代
2024-01-10
分类：综合

参考官方文档


create or replace function creatData2() returns 
boolean AS
$BODY$
declare ii integer;
 begin
 II:=1;
 FOR ii IN 1..10000000 LOOP
 INSERT INTO ipm_model_history_data (res_model, res_id) VALUES (116, ii);
 end loop;
 return true;
 end;
$BODY$
LANGUAGE plpgsql;
select * from creatData2() as tab;

插入1千万条数据耗时610s，当然字段不多的情况下。

补充：Postgresql存储过程--更新或者插入数据

要记录某一时段机器CPU、内存、硬盘的信息，展示的时间粒度为分钟，但是为了精确，输入数据源的时间粒度为6s。这个统计过程可以在应用层做好，每分钟插入一次，也可以在数据库层写个存储过程来完成，根据传入数据的时间来判断是更新数据库旧数据还是插入新数据。

同时，这些数据只需要保留一周，更老的数据需要被删除。删除动作可以每天定时执行一次，也可以写在存储过程中每次检查一下。

考虑到性能在此时没什么太大约束，而后面存储过程的接口方式更漂亮些，不用应用层去关心数据到底组织成什么样，因此实现了一个如下：


Postgresql V8.3
CREATE OR REPLACE FUNCTION insert_host_status(_log_date timestamp without time zone, _host inet, _cpu integer, _mem integer, _disk integer)
 RETURNS void AS
$BODY$
DECLARE
  new_start timestamp without time zone;
  current_start timestamp without time zone;
  c_id integer;
  c_log_date timestamp without time zone;
  c_cpu integer;
  c_mem integer;
  c_disk integer;
  c_count integer;
  date_span interval;
BEGIN
  -- insert or update
  SELECT id, log_date, cpu, mem, disk, count INTO c_id, c_log_date, c_cpu, c_mem, c_disk, c_count FROM host_status_byminute WHERE host=_host ORDER BY id DESC limit 1;
  SELECT timestamp_mi(_log_date, c_log_date) INTO date_span;
  IF date_span >= '00:00:60' OR c_id IS NULL THEN
    INSERT INTO host_status_byminute (log_date, host, cpu, mem, disk, count) values (_log_date, _host, _cpu, _mem, _disk, 1);
  ELSIF date_span >= '-00:00:60' THEN
    c_mem := ((c_mem * c_count) + _mem)/(c_count + 1);
    c_cpu := ((c_cpu * c_count) + _cpu)/(c_count + 1);
    c_disk := ((c_disk * c_count) + _disk)/(c_count + 1);
    c_count := c_count + 1;
    UPDATE host_status_byminute SET mem=c_mem, cpu=c_cpu, disk=c_disk, count=c_count WHERE id=c_id;
  END IF;
  -- delete old data
  SELECT date_mii(date(now()), 6) INTO new_start;
  SELECT date(log_date) from host_status_byminute limit 1 INTO current_start; -- omit a bug happened when date is disordered.
  IF new_start > current_start THEN
    DELETE FROM host_status_byminute where log_date < new_start;
  END IF;
END;
$BODY$
 LANGUAGE 'plpgsql' VOLATILE
 COST 100;
ALTER FUNCTION insert_host_status(timestamp without time zone, inet, integer, integer, integer) OWNER TO dbuser_test;