ACID Rules:- It is a concept for evaluation of databases and their architecture.
A:- (Atomicity) – Atomicity states the principle of All or none. This means that either all the SQL Statements within the transaction will be executed or no Sql statement will be executed.
C:- Consistency:- Consistency states that only valid data will be written into the database. That means if any Sql transaction violets the rules or constraints define on the database to make it consistent, then all the statements within the transaction will be Rollback. Or in other words the whole transaction will be rolled back.
I:- Isolation :- The Isolation state that if multiple transaction try to work on the database at the same time,then these transaction will not interfere with each other. It means the second transaction will not work unless and until the previous transaction completes its work and the work is commited.
D:- Durability:- Durability states that once the transaction is committed, then the database should not be lost in case of Software failures or hardware failures. Durability is maintained with the help of the database backups and transaction logs.
I've grown up reading Tom Clancy and probably most of you have at least seen Red October, so this book caught my eye when browsing used books for a recent trip. It's a fairly human look at what's involved in sailing on a Trident missile submarine...
Question: Can a 2008 SQL instance be used as the witness for a 2005 database mirroring setup? This question was sent to me via email. My reply follows. Can a 2008 SQL instance be used as the witness for a 2005 database mirroring setup? Databases to be mirrored are currently running on 2005 SQL instances but will be upgraded to 2008 SQL in the near future.
You may want to read Part 1 , Part 2 , and Part 3 before continuing. This time around I'd like to talk about social networking. We'll start with social networking. Facebook, MySpace, and Twitter are all good examples of using technology to let...
Last week I posted Speaking at Community Events - Time to Raise the Bar?, a first cut at talking about to what degree we should require experience for speakers at events like SQLSaturday as well as when it might be appropriate to add additional focus/limitations on the presentations that are accepted. I've got a few more thoughts on the topic this week, and I look forward to your comments.