Re: Hashing for DISTINCT or GROUP BY in SQL
From: -CELKO- <jcelko212_at_earthlink.net>
Date: Fri, 15 Oct 2010 09:59:41 -0700 (PDT)
Message-ID: <3d94f050-4da9-479c-9dd7-175feb1d4afc_at_d17g2000yqm.googlegroups.com>
Date: Fri, 15 Oct 2010 09:59:41 -0700 (PDT)
Message-ID: <3d94f050-4da9-479c-9dd7-175feb1d4afc_at_d17g2000yqm.googlegroups.com>
The later units had vacuum columns instead mechanical arms to control the tape's momentum. Did you ever see a data cell machine? It looked like a giant version of an amusement park claw machine. It grabbed a cylinder with a ribbon of mag tape, wrapped the tape around a drum, read or wrote it, then put it back in a pigeon hole. Received on Fri Oct 15 2010 - 18:59:41 CEST