On Jul 30, 2014, at 9:04 AM, Rich Shepard <rshep...@appl-ecosys.com> wrote:
> On Wed, 30 Jul 2014, Werner wrote: > >> I don't like using 'name' columns as primary keys I would instead use an >> 'id' column and would set 'index=True' on the name column. > > Werner, > > The use of natural keys (such as a vehicle VIN, the US's SSN, or equipment > serial number) is prefered over an artificial, meaningless, integer key to > prevent duplicate data. See any of Joe Celko's SQL books. Celko's books are great but surrogate integer PKs are an unavoidable practice within relational databases, they are a requirement of most DBAs I've dealt with as they perform predictably in terms of indexing and space requirements, especially considering that a PK implies the format of all the FKs that will refer to it. Typically a UNIQUE constraint is placed on the "natural" key to prevent dupes. In my own experience we actually tried using meaningful UUIDs as primary keys in a project some years ago and it was an utter disaster. All PK / FK indexes quadrupled in space and performance suffered terribly. This was on a Postgresql backend which should have been a better performer in a non-standard context like that (on a big ol' DB like SQL server, forget it). -- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at http://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
