参考
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;
以上为个人经验,希望能给大家一个参考,也希望大家多多支持www.887551.com。如有错误或未考虑完全的地方,望不吝赐教。