Re: postgresql storage and performance questions
От | Alvaro Herrera |
---|---|
Тема | Re: postgresql storage and performance questions |
Дата | |
Msg-id | 20071120124954.GE5167@alvh.no-ip.org обсуждение исходный текст |
Ответ на | Re: postgresql storage and performance questions ("Josh Harrison" <joshques@gmail.com>) |
Список | pgsql-general |
Josh Harrison escribió: > > On 11/19/07, Josh Harrison <joshques@gmail.com> wrote: > > > > > I have 2 tables with 2 cols each( 1 numeric(8,0) and 1 varchar(3) ). > > > In table1 both the cols are filled and in table2 the varchar colm is null > There were a couple of things we noted. > 1. Tablesize twice as much than oracle-- Im not sure if postgres null > columns has any overhead since we have lots of null columns in our > tables.Does postgresql has lots of overhead for null columns? No, NULLs are stored as a bitmap for each tuple and they are quite efficient. Probably the reason for the difference is the numeric field which Oracle may be optimizing as a plain integer. Did you try declaring the column as INTEGER in Postgres? Please do not top-post. -- Alvaro Herrera http://www.amazon.com/gp/registry/5ZYLFMCVHXC "Everything that I think about is more fascinating than the crap in your head." (Dogbert's interpretation of blogger philosophy)
В списке pgsql-general по дате отправления: