Limitations of Running Multiple Instances of MS SQL EXPRESS

Question

I plan on installing Multiple Instances of MS SQL EXPRESS on my Development Server.

I am hoping this will let me get around the limitations of SQL EXPRESS:

• 1 GB of RAM,
• 1 CPU
• Database size max 4 GB

[I understand and wish that I could afford a full licence version of SQL Server.]

So, would this work? Would each instance have their own independent limitations?

Answer 1

If you have an MSDN subscription then you can install the Development version and I don't believe that has any restrictions...of course it's for development purposes only.

You can purchase SQL Server Developer Edition from Microsoft at this link...it's $50

http://store.microsoft.com/microsoft/SQL-Server-2008-Developer-Edition/product/C5EA00C9?WT.mc_id=productinfocenter

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As of 2016 (?) SQL Server Developer Edition is Free, downloadable at microsoft.com/sqlserver.

Answer 2

The answer to your question is yes.

All instances will have their own independent limitations.

Problems that you will face are:

• Obvious performance issue.
• OS will decide which processor they will use, and there is a good chance that they will all use the same one. You need to try that.
• Servers need to listen on separate ports.
• Separate master databases, separate collations, no easy cross-database queries.

Answer 3

If you can get this done, every instance will behave and run under the same limitations. Also, you will need to configure the ports since each instance will attempt to listen on the same port.

Answer 4

The problem is that, by design, an SQL Server will take as much memory as it can (the larger its cache, the better its performance will be) and, as such, running 4 SQL Servers will simply fight for your RAM (1gig is nowhere near enough.)

That said, the maximum database size is 4 gig, but, unless you’re dealing with images, you'll be surprised just how much that is.

We used SQL Express and it was fine for what we were using it for (10 user client/server application), plenty of SQL and plenty of queries every second. I would recommend using the express version and looking into a better one in the future.

FYI: Microsoft Small Business Server (SBS) comes with a workstation version of SQL Server plus Exchange which means it is EXTREMELY cost effective for a starting business.

Also, if your idea is good, you should look at the Microsoft programs for new companies (It used to be called empower, it has a new name now...). They are really really good in terms of software, especially server software.

Answer 5

Since it is a development server, I would second the recommendation to go with a copy of Developer Edition. Developer Edition is a specially licensed version of Enterprise Edition which allows you to run it on operating system versions where Enterprise Edition would not normally be allowed to run. The catch is it an only be used for development. At $50, it's well worth the cost.

The problem with running multiple instances is you face the prospect of resource contention for CPU and memory between the instances. You can throttle the memory for each instance and things of that sort, but if you have the option, going with the Developer Edition instance will be simpler and easier to manage.