db locks

Hi!
Can you tell me what are the reasons of db locks? What
can lead to DB lock? We have 14 concurent users accessing
the same database (financial system), locks often come up
and users have to wait on each other.
Can be db lock caused by wrong DB structure (relationship
schema), by way of opening a recordset (on application
layer) or is it just case of sql server transactions
management?Gabriel
http://www.sql-server-performance.c...ucing_locks.asp
http://www.sql-server-performance.com/deadlocks.asp
http://www.sql-server-performance.com/blocking.asp
"Gabriel" <bigg@.stonline.sk> wrote in message
news:4c5c01c473b0$9e865aa0$a501280a@.phx.gbl...
> Hi!
> Can you tell me what are the reasons of db locks? What
> can lead to DB lock? We have 14 concurent users accessing
> the same database (financial system), locks often come up
> and users have to wait on each other.
> Can be db lock caused by wrong DB structure (relationship
> schema), by way of opening a recordset (on application
> layer) or is it just case of sql server transactions
> management?|||DB locks exist to ensure the data is correct...Imagine you are in a
transaction where you plan to change the price of a book from $19.99 to
$25.00.... while in the transaction, you take a phone call. Your changes
are still pending the commit of the transaction. ( what you do not yet
realize is that you mistakenly changed the price of the book to 25 cents)...
A salesman gets a call from Barnes and Noble and sells 100,000 copies of
that book for 25cents each... You complete your call, realize your mistake
and roll the transaction back.
DB locks prevent someone else from using your data which is in the process
of being changed, until the change is committed... Of course there are
other examples as well...
But locks( which serve as a traffic cop on a busy road) are always necessary
in multi-user environments.
Wayne Snyder, MCDBA, SQL Server MVP
Mariner, Charlotte, NC
www.mariner-usa.com
(Please respond only to the newsgroups.)
I support the Professional Association of SQL Server (PASS) and it's
community of SQL Server professionals.
www.sqlpass.org
"Gabriel" <bigg@.stonline.sk> wrote in message
news:4c5c01c473b0$9e865aa0$a501280a@.phx.gbl...
> Hi!
> Can you tell me what are the reasons of db locks? What
> can lead to DB lock? We have 14 concurent users accessing
> the same database (financial system), locks often come up
> and users have to wait on each other.
> Can be db lock caused by wrong DB structure (relationship
> schema), by way of opening a recordset (on application
> layer) or is it just case of sql server transactions
> management?