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How ACID is Jet

I like the idea of storing your website in a Database but how reliable is Jet. As of Access 97 Microsoft didn't seem to have too much confidence in it (http://support.microsoft.com/support/kb/articles/Q222/1/35.asp ). Is Jet really a realiable place to be putting all my data. Since Joel seems to have "bet the company" on this decision, I'm sure there's a reason, I'd just like to know what it is.

Rob Schlaff
Friday, November 16, 2001

That KB article is probably just because Microsoft got tired of cheap webmasters running their smaller sites off of Jet (free) instead of SQL Server ($$$).

But to answer the question: we "bet the company" on ODBC, not Jet; as customers need larger and larger CityDesk sites we can switch them to SQL Server or Oracle painlessly. (In fact you can use the Access upsizing wizard right now to move your CityDesk sites onto SQL Server.)

Joel Spolsky
Friday, November 16, 2001

I figured as much. For a couple of users Jet makes a lot of sesne, I'm just curious if anyone has done any stress testing on Jet with multiple users, row locking, etc...

Rob Schlaff
Friday, November 16, 2001

The results I've seen show pretty consistently that Jet is faster for small/light use; at some point you pass a threshhold where SQL Server becomes faster.

Joel Spolsky
Friday, November 16, 2001

I'm far more worried about corruption of the database rather than speed. And if Jet really supports ACID it has to support transactions -- but how do you support things like durability without a transaction log written to disk? And if you support transactions you can easily have deadlocks, so how does Jet deal with that? I don't know that these questions are really valid but it makes be believe that Jet isn't completely ACID.

Rob Schlaff
Friday, November 16, 2001

How would I tell CityDesk to use my SQL Server version of my website vs. the "*.cty" Access file? I don't see where CityDesk is using a DSN, so it doesn't appear to be as simple as switching out the DSN pointer. If CityDesk is looking for a physical Access "*.cty" file, it doesn't appear that there is a seamless upsizing migration path...Will this require a different version of CityDesk?

Jonathan Goodyear (aka angryCoder)
Saturday, November 24, 2001

On second thought, you "could" use linked tables to SQL Server in Access, but that's a cheeseball solution. If I want to go to a SQL Server based solution, I'd want to eliminate Access from the picture entirely...

Jonathan Goodyear (aka angryCoder)
Saturday, November 24, 2001

Not entirely cheezy :) Indirecting through a .CTY file makes life a little bit easier because you can just pass out the .CTY file to your team in order to let everybody hit SQL Server. And it simplifies my life as a programmer because I can use the Access dialect of SQL consistently. And until you get to thousands of editors, I doubt if the performance will be a bottleneck.

Joel Spolsky
Monday, November 26, 2001

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