Re: how to get the total number of records in report
От | Merlin Moncure |
---|---|
Тема | Re: how to get the total number of records in report |
Дата | |
Msg-id | AANLkTik+wEqEF=yWQrvYn6wN7YyJGoMtPu2-0jCTv+8F@mail.gmail.com обсуждение исходный текст |
Ответ на | how to get the total number of records in report (AI Rumman <rummandba@gmail.com>) |
Ответы |
Re: how to get the total number of records in report
|
Список | pgsql-performance |
On Mon, Oct 18, 2010 at 1:16 AM, AI Rumman <rummandba@gmail.com> wrote: > At present for reporting I use following types of query: > select crm.*, crm_cnt.cnt > from crm, > (select count(*) as cnt from crm) crm_cnt; > Here count query is used to find the total number of records. > Same FROM clause is copied in both the part of the query. > Is there any other good alternative way to get this similar value? Probably the best way to do this type of thing is handle it on the client. However, if you want to do it this way and your from clause is more complex than 'from table', you can possibly improve on this with a CTE: with q as (select * from <something expensive>) select q.* q_cnt.cnt from q, (select count(*) as cnt from q) q_cnt; The advantage here is that the CTE is materialized without having to do the whole query again. This can be win or loss depending on the query. merlin
В списке pgsql-performance по дате отправления: