Viewing 15 posts - 18,781 through 18,795 (of 49,552 total)
If you use this method, you can calculate nonclustered indexes as well, much the same way.
GilaMonster (4/24/2012)
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
April 26, 2012 at 3:31 am
opc.three (4/25/2012)
GilaMonster (4/25/2012)
opc.three (4/25/2012)
Yes. If the error was such that it left the transaction in a state where it cannot be rolled back
A transaction can never be in a state...
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
April 25, 2012 at 3:28 pm
jitendra.padhiyar (4/25/2012)
Non-Repeatable reads: Rows that disappear are non-repeatable reads.That means same rows but data will be chagned.
Deleted or updated. So you could run the same query twice, get this...
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
April 25, 2012 at 2:51 pm
opc.three (4/25/2012)
Yes. If the error was such that it left the transaction in a state where it cannot be rolled back
A transaction can never be in a state where it...
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
April 25, 2012 at 2:10 pm
durai nagarajan (4/25/2012)
If it comes to catch wont that be definitely error.
Yes it will. Control only passes to the catch block when an error happens.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
April 25, 2012 at 2:04 pm
To explain, in repeatable read isolation level, shared locks are held until the transaction commits or rolls back. So when the delete comes along and tries to delete a row...
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
April 25, 2012 at 1:26 pm
http://en.wikipedia.org/wiki/Isolation_%28database_systems%29
Phantom reads
A phantom read occurs when, in the course of a transaction, two identical queries are executed, and the collection of rows returned by the second query is different from...
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
April 25, 2012 at 1:22 pm
jitendra.padhiyar (4/25/2012)
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
April 25, 2012 at 1:04 pm
GSquared (4/25/2012)
Unrepeatable example: Update Joe's last name from Smith to Smithe between reads. Different data, same rows.Phantom Rows: 5 rows one time, 4 or 6 the next time.
6 or...
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
April 25, 2012 at 1:03 pm
GilaMonster (4/25/2012)
If anyone's willing to offer suggestions, I'm looking for examples of two things:
Query optimisation/query execution myths (for a blog post series). Things like implicit conversions always...
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
April 25, 2012 at 1:00 pm
Nested trans is certainly an idea...
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
April 25, 2012 at 12:58 pm
Dirty reads (possible only in read uncommitted isolation level):
Read data that is subsequently rolled back and was never part of the durable contents of the database. Eg
Begin transaction
update Employees set...
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
April 25, 2012 at 12:48 pm
Yet another topic shift...
If anyone's willing to offer suggestions, I'm looking for examples of two things:
Query optimisation/query execution myths (for a blog post series). Things like implicit conversions always cause...
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
April 25, 2012 at 12:40 pm
GSquared (4/25/2012)
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
April 25, 2012 at 11:26 am
TheSQLGuru (4/25/2012)
GilaMonster (4/25/2012)
TheSQLGuru (4/25/2012)
SQLIOSIM is the tool to use to validate that an IO subsystem will properly handle SQL Server IO-style workloads.
But SQL needs to be stopped when running that....
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
April 25, 2012 at 11:25 am
Viewing 15 posts - 18,781 through 18,795 (of 49,552 total)