This editorial was originally published on Aug 3, 2012. It is being re-run as Steve is on vacation.

One of the interesting facts I saw a few years ago talked about storage in enterprise environments. There was research that showed many enterprise applications had 6 or 7 copies of their large databases inside the organization. In addition to the production copy, there were many other copies in use, resulting in an explosion of growth. That wasn't surprising, and it was one of the drivers for implementing compression in many databases.

While the cost of storage is constantly coming down, it's still expensive for enterprise class hardware, especially in a large SAN device. Today I wanted to ask those of you that work on real world systems to make a quick count of your own system, and let us know. I can't decide if 6 copies of a production database is high, or low.

How many copies, on average, of your production databases are in your company?

I suppose you could count backups as a copy, since it's disk space usage and you have to pay for it. If you count backups, let us know, but I'm thinking just about the test systems, development systems, HA or DR systems that might receive copies of the data. Some of those secondary systems might be in use for other purposes, such as reporting from readable secondaries in an AlwaysOn scenario. Whether they are or not, they are still copies of your database.

I used to think that four or five copies would be a lot, but with the advances in technology that allow different DR options, and the cheap local storage available on today's desktops and laptops, I wonder if seven or eight copies might be more accurate.

Take a count today; you might surprise yourself with the results.

Steve Jones

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