Re: Creating exponential sequences
От | Rod Kreisler |
---|---|
Тема | Re: Creating exponential sequences |
Дата | |
Msg-id | JNEGKNDJGBKLBDGPOPFOIEJNDCAA.rod@23net.net обсуждение исходный текст |
Ответ на | Re: Creating exponential sequences (Tom Lane <tgl@sss.pgh.pa.us>) |
Список | pgsql-novice |
My last example should have used an int8. Not in some instances. For example, I'm working on a structure for a real estate db. Each property has about 15 different attributes that are best described as sets, e.g. rooms (kitchen, living room, utility, family room, etc) Each set is limited and 64 would more than suffice for all of them. As it is a 1:M join table is required to link the properties to each attribute. Now the number of elements in each set varies, rooms would be the largest with an average of around 11, some will only be two or three. We are projecting 500,000 properties within the first 6 months. That would equate to a 1:M join table containing 5.5 million entries. We will almost exclusively be querying for one property at a time, so grabbing a single value from the main property table (which we will have to query anyway) would be preferable. > -----Original Message----- > From: pgsql-novice-owner@postgresql.org > [mailto:pgsql-novice-owner@postgresql.org]On Behalf Of Tom Lane > Sent: Monday, October 07, 2002 11:13 PM > To: Rod Kreisler > Cc: pgsql-novice@postgresql.org > Subject: Re: [NOVICE] Creating exponential sequences > > > Rod Kreisler <rod@23net.net> writes: > > Is there any way to create an exponential sequence rather than > incremental? > > What I would like is a sequence that would start at 1 and grow > exponentially > > by 2. (i.e. 1,2,4,8,16,32....) > > A sequence that will bomb out after 32 or 64 increments seems of limited > use ... > > regards, tom lane > > ---------------------------(end of broadcast)--------------------------- > TIP 3: if posting/reading through Usenet, please send an appropriate > subscribe-nomail command to majordomo@postgresql.org so that your > message can get through to the mailing list cleanly > >
В списке pgsql-novice по дате отправления: