MySQL Max

Anon

I heard that MySQL Max supports transaction, what is transaction anyways?

Anon

Imagine you enter this neat SQL in your RDBMS:

DELETE FROM table WHERE 1;

then realize YOU HAVE DELETED THE MAIN TABLE FROM THE DB AND YOU HAVE NO BACKUPS (OH, MAN... YOU'RE FIRED)

A transaction prevents this. You can "rollback" it and nothing will have happened.

Dunno about MySQL Max supporting 'em. They are real useful for sloppy people, but if you are extra-careful, you don't really need 'em THAT MUCH.

Make backups to .txt files.

fLIPIS

Anon

They are real useful for sloppy people but if you are extra-careful, you don't really need 'em THAT MUCH. >>

That's utter bollocks.

You always need to use transactions when handling vital data, and it has nothing to do with sloppiness.

flipis

Sure, sure. Tell taht to me, i make a Backup on my DB each day because MySQL doesn't support transactions.

Oh, and I'M GETTING FED UP OF FLAMERS.

I just say you can live without transactions (i do), and that if you are extra-careful you can avoid needing them (of course, depending on th RDBMS u use)

I said, i'm fed up if being flamed in this forum.

fLIPIS

Anon

Flamed? No one was flaming.

You need transactions for much more than just 'undo'.

A simple (and common) example is money-transfer in a bank. You have to take $50 from Jacks account and put it into Janes. You have to do both or neither one.

You start a transaction, then you update Jacks account (eg. 1000-50) and after that Janes account (eg. 100+50). Nothing is done yet.
If both of the previous updates were successful, you commit the transaction and the changes are made permanent (or if the transaction fails, neither one is made permanent).
If either one of those failed, you rollback. Nothing will be changed (you don't end up with Jacks account having $1000 and Janes $150 as you could if your script would crash between your manual undo).

So think things thru before you go calling people flamers for nothing.

flipis

Someone should also think, before quoting my words as "utter bollocks" (I can be spanish, but i know enough 'bout english to know this is not a nice thing to say)

I didn't say transactions were just for undoing. I tried to explain, simply, what they are. And to say to Bob he doesn't need them that much (depending on what he wants to do)

Anyway, peace.

fLIPIS

mattr

Transactions are hardly used for 'undo'ing a programming mistake. They are used primarily for what Koffa posted, because if you type
DELETE TABLE bob

sf
sf

The engine still has not executed it yet until you decide to terminate and execute the statement (in MS SQL/Sybase you need to say 'GO', Oracle ;, etc.).

mattr

Oops, you did include a ;, my bad. In any case, the 'oops factor' is not the reason why x-acts came into being. They're there primarily to enforce 'ACID'-ity.

Anon

I'm giving up. You're right, i'm a stupid. Happy now? Please stop flaming me, mate.

fLIPIS

Anon

Never give up. Here is the information you need.

The transactions are the parts of entire jobs.

Let say you want to run a big-update query and check out the things every 5th line (of the query). If you define transactions at every 5h line, and if something goes wrong you may rollback the first 5th line or some others not entire query.

Cheers,

-Kenan Bektas
Ottawa, Canada