Sunday, February 12, 2012

CHAOS

How come there is a Chaos isolation level in the Advanced tab in DTS package
properties? Was someone having a bad day and thought there life was in chao
s?Hi, Andre
Books Online says (in the "DTS Package Properties (Advanced Tab)"
topic):
Transaction isolation level
Select from one of these levels:
Chaos. You can see uncommitted changes made by other transactions,
but update locks are not held to the end of the transaction.
Rollback is not supported. This isolation level is not supported
by SQL Server.
Read Committed. You cannot see changes made by other transactions
until those transactions are committed.
Read Uncommitted. You can see uncommitted changes made by other
transactions.
Repeatable Read. You are guaranteed not to see any changes made by
other transactions in values it has already read.
Serializable. This option guarantees that all concurrent
transactions will interact only in ways that produce the same effect
as if each transaction were executed entirely one after the other.
Razvan|||It is an unsupported isolation level. In general, with this isolation level,
a transaction can view the uncommitted changes made by other transactions.
There is no real control over the update locks -- they may or may not be
held till the end of transaction. Failures can be fatal, will not preseve
ACID properties and there are no rollbacks.
Anith|||It is used by the SQL engine itself. Why it made it on some GUI tab is
anyone's guess.
The only way I've even seen it changed was with fiddling with the PSS struct
while under a debugger.
"Andre" <Andre@.discussions.microsoft.com> wrote in message
news:FC959C18-4C04-41A9-B49F-BEA33BD8836A@.microsoft.com...
> How come there is a Chaos isolation level in the Advanced tab in DTS
> package
> properties? Was someone having a bad day and thought there life was in
> chaos?

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