Is Access stable DB program?

[gear]

I believed that Access is a stable DB program. It looks like I may have to change this view. Yesterday, due to some fault in power supply (SMPS), my PC suddenly went off while I was working in my Access DB. My DB is a personal DB (single user). Today, after replacing the SMPS, when I opened my DB, Access gave a message that my DB is corrupted while it was being used last time. It asked to attempt repair with Yes/No button. I clicked the Yes button and it did nothing. In my third attempt, I was able to open my DB but I am worried whether it will work as before. Could the experts in this forum throw some light about Access DB' stability and measures to prevent corruption? Grateful for advice.

 

[MicroE]

Check out: http://www.granite.ab.ca/access/corruptmdbs.htm

 

[ChrisO]

I doubt that we can blame Access for malfunctioning during a power failure, what I think we can say is that Access is as stable as we allow it to be.

In general, reliability can not be guaranteed to be 100%. It may be required to guarantee it to some level such as 99.95% but that costs money. The reason for the high cost is that reliability is often refereed to as ‘system availability’. System availability mostly stems from redundancy i.e. duplication to two, three and even four levels.

So it really boils down to ‘you generally get what you pay for’.

Consider the power to your PC’s mother board. One mains supply that is out of your control and one SMPS that failed.

Then consider an alternative…
Two independent mains feeds from the state grid feeding two isolation transformers, correctly grounded on the primary and secondary sides, feeding two UPS’s, feeding two SMPS’s both of which feed common DC rails via two series blocking diodes. You will also need to monitor failures within the power supply system so that action can be taken to fix the failed component and, if necessary, proceed to an orderly shutdown by saving everything to disk before they loose power.

And that’s just the power supply duplicated and the motherboard could still fail.

That sort of thing costs money and most people don’t bother with it.

But, if we don’t pay for ‘system availability’ then we get exactly what we paid for…

Regards,
Chris.

 

[The_Doc_Man]

Gear, I'm working an Alpha / OpenVMS machine with ORACLE as my primary database. (Access stuff is secondary.) We have a UPS on the box, plus a big motor-generator set and daily incremental backups and weely full backups. Every now and then we STILL get a corruption problem when the power hiccups at just the wrong time with just the wrong duration to confuse the power recovery code.

So I cannot blame Access for giving you the creepy cruds after a power hit.

All you can ever hope to do is try to forestall such events. Invest in a UPS. I'm not trying to see any brand, but for a single PC, you can get an APC power unit that would let you at least have an orderly shutdown for about $100. Is your data reliability worth that much? Then there is the matter of backing up your database on a regular schedule and NEVER VARY FROM THAT BACKUP SCHEDULE!!!!!!!!! NEVER. If you have a CD burner or a DVD burner it isn't that hard to assure proper backup. Sheesh, a CD-ROM (WORM-style, or Write Once, Read Many times) costs 10 cents in small quantity and a nickel a shot in larger quantity.

You cannot hope to stop a corruption event. You can, however, try to minimize the time and data lost to it.

 

[tehNellie]

I'm working an Alpha / OpenVMS machine

VMS is still alive? I started out in IT sat in front of a Terminal with a DCL manual.

Now I [try to] run Access/SQL-Server systems as pennance

 

[The_Doc_Man]

tehNellie, OpenVMS is VERY much alive in banks and hospitals due to its near non-crashable nature. Of course, that's because it is a mature (read "old") product for which lots of the bugs have been worked out.

But it goes farther than that. Do you know who strongly contributed to VMS? Dave Cutler. Do you know who wrote most of Windows NT? Dave Cutler. Is it merely a coincidence that VMS and WNT are just one letter apart in each column? If you've seen Dave's code, probably not. Is it mere coincidence that since WinNT, Windows Kernel structure has migrated strongly towards the model used by VMS? Probably not. (Again, mature products make good models.)

 

[WayneRyan]

Doc,

I grew up with PDP-11s and VAXes. I had a lot of ORACLE apps that
ran forever under the VMS platform.

When you look and see that the computer has been running for MANY,
MANY months since the last reboot, it must be a stable system.

With the stability of DEC and ORACLE, I left quite a few apps
unattended for literally years and they did fine.

btw, I really miss some of the VAX utilities like sorting, file
comparisons, etc.

btw, You can do anything in DCL, but it sure is slow. (just kidding).

BUT, I REALLY MISS THE VAX EDITOR --> EDT

The keypad driven macros (CTRL-K ...) make text manipulation quite
easy. There used to be some shareware emulators, but I can't find
any now.

Any help here?

thx,
Wayne

 

[The_Doc_Man]

Wayne, you can speed up DCL by judicious choice of some executables that you run as foreign commands. For quick/dirty little programs, write it in DCL and then convert it to BASIC. The string paradigms are identical as to operators and methods. So DCL becomes an interpretive prototyping tool.

You wouldn't believe just what you can do in DCL. I've done a few tricks to provide floating-point numbers in DCL (DOUBLE format). It's a long story.

As to stability, I once had a VAX 11/780 with a known failing memory card. It just isolated the memory page onto the bad-page list and ran for 183 days without a reboot or crash DESPITE having a failed memory card. Can't beat that with a stick.

I did a lot of my dissertation work on a PDP-11/15 (a.k.a. LAB-11) and fed the data to a PDP-10 (KA10) with TOPS-10 for the O/S. But the Alpha is a very stable platform, too. You'd like it. Just don't have any delusions about writing assembler code for it, it's a bloody RISC processor. But sweet... four-way pipelining, 64-bit data bus, and our systems are all 4-way symmetrical multiprocessing besides the pipelining.

 

[tehNellie]

reminds me of the story of one of our Script servers "brf2" and the call that came down from the comms room.

"help! BRF2 has fallen over"
....
<sounds of frantic typing>
....
"What do you mean? It looks fine, in fact I've never seen it running so good"
...
"No, I mean it has literally fallen over, one of the floor tiles has broken and it's lying on its side."
...
"Oh, OK, we'll be right there".

I was aware of the relationship (pardon the pun) between VMS and NT, I moved around a bit between platforms and having worked on DCL came in very handy at times digging around behind the scenes in NT, much to the chagrin of the "pure" windows support guys.

 

[The_Doc_Man]

I'm glad you used quotes around "pure." I've never seen PURE and WINDOWS used in the same sentence unless CRAP was also present.