Hacker News Reader

Comment by pklee | Hacker News Reader

I am not sure about MS Access. From what little I know 2 people opening from network drive would mostly result in database being corrupt.

View on HN

MS Access "allowed" it. SQLite actually works.

I understand the distinction now :), thank you. Funny.

Access is actually designed to work in a multiuser situation over a LAN for concurrent read and write. SQLite isn't afaik. As long as the LAN was cabled I never saw any issues. The only reason it was necessary to move to a server type database was because people were insisting on wifi networking.

I'm not sure I understand what the physical transport has to do with this. Can you please expand a bit?

Maybe disconnect and reconnect cause windows network share to lose locks or something like that.

Yes, for Access (and sqlite?) it is the client computers that do the edits directly to the database file, rather than via a mediating server side process, so they are particularly vulnerable to network interruptions while in the middle of an edit. Cable is far more reliable than wifi and so far fewer interruptions. I think that's it.

Ok but you cant really say you support network access if you rely on it to be flawless. Working fast, maybe but not reliably working if your network is not super reliable is not really support.

It was a different time.

Back in the day, which was a Wednesday

Race conditions not triggering when the transport is fast enough?

It might have been designed for it. It was poorly designed for it. It was a clustfuck of corruption when actually utilized

You basically had to engineer around the corruption risks for anything actually in production. Data redundancy, old-school 'Save' buttons (your work isn't properly saved until you click it, because it sends copies of that work to multiple backends) and isolating users as much as possible to their own 'shards' was part of how I saw it kludged through in the real world.

There was still a lot of weird behavior, though, and while you could reduce data loss you couldn't eliminate it.

Penny wise pound foolish. I had a president waste two to three hours a day instead of using a 40 dollar service to take care of the incredibly simple and repetitive task. Eventually when I was planning to leave anyways I asked him what his time was with per hour. I guess it was less than minimum wage at the time. (5.25 an hour)

I'm probably going to have nightmares filled with screens of the access database corruption dialogs

What's anyone's time worth? Might have kept him from doing something foolish.

Valid point. He did defraud the federal government for 600k. If he had more time on his calendar he could have fucked over the American taxpayers ever more.

It depended. It suited a small cabled office with 10 to 15 computers fine. I saw such setups work fine for 12 years without corruption. But when wifi came along people started connecting that way, sometimes unintentionally, and corruption became an issue. So then we bit the bullet and moved the backend to a server database. Not a single database corruption since.

But this is the difference between supporting concurrent access or not. The fact that the feature relied so much on network reliability means that race conditions still existed.

I'm not arguing with you but the fact remains that unlike SQLite, Access doesn't lock the database file so that only one user can write at a particular moment, it's more granular than that. It's also the fact that this worked very well for databases on small cabled LANs where no more than a dozen-ish computers might be interacting with the database at any one time. It was never designed for use over the internet (having said which I have maintained a forum running an Access mdb file as its backend since forever without a hitch the forum software process does the database edits so it's like a database server process in a way I suppose).

Reply on news.ycombinator.com