Viewing 15 posts - 3,376 through 3,390 (of 49,552 total)
In short, yes. The first it two seeks against the table (assuming appropriate indexes), the second is a join between two tables, might be a loop join, might not.
The difference...
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
March 30, 2016 at 8:05 am
Not offhand, but you can get a quick and dirty check by copying large files from one say the backup drive to the data drive and see how long 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
March 30, 2016 at 7:48 am
You're not going to get the desired output with a join, left or right.
I don't know what bo universe is, If it accesses SQL server, can you put the code...
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
March 30, 2016 at 7:38 am
Version probably not much of a difference. Backup and restore are IO-bound operations. Test the kind of IO throughput you get on the VM, compare to the physical server.
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
March 30, 2016 at 7:30 am
Backup and restore times are mostly a function of IO throughput. Do the VMs and the physical server have the same IO capabilities?
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
March 30, 2016 at 7:09 am
You can't just change an APPLY to a JOIN and expect the same results, you won't get them.
An APPLY runs the query once for each row of the outer query,...
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
March 30, 2016 at 6:39 am
It's the plan 'shell' for the SELECT, it's not a complete plan. It's kinda a pointer to the parameterised form of the plan.
http://daleburnett.com/2011/08/forced-parameterization/
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
March 30, 2016 at 6:35 am
nadersam (3/30/2016)
GilaMonster (3/30/2016)
Varchar(max) is a very different data type. It's got additional overheads because it's off-row data, It's definitely not something you'd use on all columns.
yes you are right off...
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
March 30, 2016 at 4:57 am
Varchar(max) is a very different data type. It's got additional overheads because it's off-row data, It's definitely not something you'd use on all columns.
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
March 30, 2016 at 3:11 am
Hugo Kornelis (3/29/2016)
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
March 29, 2016 at 3:53 pm
Won't change things much. Rebuild still creates the new index and drops the old. The only thing that moves to TempDB is the sort space required.
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
March 29, 2016 at 12:11 pm
Aggregate function.
https://msdn.microsoft.com/en-us/library/ms173454.aspx
GROUP BY isn't an aggregate, it's a clause in the statement that defines what columns the aggregates are computed by.
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
March 29, 2016 at 9:56 am
The first of the month.
01-Jan-15 is a valid date. Jan-15 is not.
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
March 29, 2016 at 9:31 am
With a cast to DATE in the middle
DECLARE @halfDate NVARCHAR(6) = 'Dec-15'
SELECT DATEname(MONTH, CAST('01-'+@halfDate AS DATE)) + ' ' + CAST(YEAR(CAST('01-'+@halfDate AS DATE)) AS VARCHAR(4))
Not sure if it's cleaner though.
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
March 29, 2016 at 9:13 am
Neither of those statements are true.
Using AdventureWorks
Valid:
SELECT CustomerID, SUM(TotalDue) FROM Sales.SalesOrderHeader
GROUP BY CustomerID, SalesOrderNumber, TerritoryID
Valid:
SELECT CustomerID, LEFT(SalesOrderNumber,5), SUM(TotalDue) FROM Sales.SalesOrderHeader
GROUP BY CustomerID, SalesOrderNumber, TerritoryID
Any column referenced in the...
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
March 29, 2016 at 9:05 am
Viewing 15 posts - 3,376 through 3,390 (of 49,552 total)