First, please ALWAYS include the version and O/S, even with basic questions.
I'm not sure what you mean by doubles. Do you mean bigint data type, or do you mean use two columns for a primary key? Either way it's pretty simple. If you mean a bigint, then probably best to use serial data type, which will default to the next value. If you mean use two columns for a Primary Key, the you just specify the columns. EG: CONSTRAINT PRIMARY KEY table_name_pk PRIMARY KEY (col1, col2) On Fri, Apr 17, 2015 at 11:34 AM, Kynn Jones <kyn...@gmail.com> wrote: > I have some data in the form of a matrix of doubles (~2 million > rows, ~400 columns) that I would like to store in a Pg table, > along with the associated table of metadata (same number of rows, > ~30 columns, almost all text). This is large enough to make > working with it from flat files unwieldy. > > (The only reason for wanting to transfer this data to a Pg table > is the hope that it will be easier to work with it by using SQL > queries to extract subsets of it, than by, e.g., writing programs > that must scan the entire matrix every time they're run.) > > My plan is to add one extra column to the Pg tables to serve as > the primary key joining the data and the metadata tables > together. > > One consideration that is complication the choice of primary key > is wanting to have the ability to store chunks of the data > table (not the metadata table), including the PK column, as > matrices of doubles. In its simplest form, this would mean using > doubles as primary keys, but this seems to me a bit weird. > > I'm willing to go ahead with this, but I wanted to ask for your > feedback on the whole thing. In particular I'd like to know if > there are there standard ways for using doubles as primary keys, > and, conversely, if there are known pitfalls I should be looking > out for, but I welcome any other words of wisdom you may have on > this topic. > > Thanks in advance! > > kj > > > -- > Sent via pgsql-general mailing list (pgsql-general@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-general > -- *Melvin Davidson* I reserve the right to fantasize. Whether or not you wish to share my fantasy is entirely up to you.
