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GeneralRe: MSSQL - How can I reference a column to update using a variable?? Pin
Mycroft Holmes21-Dec-10 13:19
professionalMycroft Holmes21-Dec-10 13:19 
GeneralRe: MSSQL - How can I reference a column to update using a variable?? Pin
JTRizos22-Dec-10 6:26
JTRizos22-Dec-10 6:26 
GeneralRe: MSSQL - How can I reference a column to update using a variable?? Pin
Mycroft Holmes22-Dec-10 11:13
professionalMycroft Holmes22-Dec-10 11:13 
GeneralRe: MSSQL - How can I reference a column to update using a variable?? Pin
JTRizos22-Dec-10 11:48
JTRizos22-Dec-10 11:48 
QuestionExplain Explain for me! Pin
Chris Meech20-Dec-10 7:04
Chris Meech20-Dec-10 7:04 
AnswerRe: Explain Explain for me! Pin
Jörgen Andersson20-Dec-10 10:07
professionalJörgen Andersson20-Dec-10 10:07 
RantRe: Explain Explain for me! Pin
Mycroft Holmes20-Dec-10 16:14
professionalMycroft Holmes20-Dec-10 16:14 
GeneralRe: Explain Explain for me! Pin
Jörgen Andersson20-Dec-10 23:51
professionalJörgen Andersson20-Dec-10 23:51 
A DBA that doesn't say "it depends", hasn't been presented a specific enough case.

But I have found one "rule" that hasn't failed me yet when it's about aggregating data. It's all about minimizing the amount of data (in bytes, not necessarily rows) that the db has to handle.

Say for example that you want to join together several tables, some holding descriptive texts and some other holding data that should be aggregated.
If you make a query that makes the joins and the aggregation in one go, then the db will join first and aggregate later, creating millions of rows with text that will just be grouped when the aggregation happens. Creating all this in memory, or in worst case the HD, takes time.

Instead I'm breaking down all queries into smaller parts that I materialize using subquery factoring (CTE for you SQLServer people) and then I join the results from them together.
So I'm making one or more queries that aggregate the data, and one or more separate queries for the descriptions, and then I join the aggregated results together in the end.

This method is often magnitudes faster than a onepiece query.

"When did ignorance become a point of view" - Dilbert

GeneralRe: Explain Explain for me! Pin
Chris Meech21-Dec-10 2:11
Chris Meech21-Dec-10 2:11 
GeneralRe: Explain Explain for me! Pin
Chris Meech21-Dec-10 2:16
Chris Meech21-Dec-10 2:16 
QuestionHow to Display transactions happened in sqlserver 2005 Pin
nainakarri19-Dec-10 21:58
nainakarri19-Dec-10 21:58 
AnswerRe: How to Display transactions happened in sqlserver 2005 Pin
Hiren solanki19-Dec-10 22:49
Hiren solanki19-Dec-10 22:49 
GeneralRe: How to Display transactions happened in sqlserver 2005 Pin
nainakarri20-Dec-10 0:00
nainakarri20-Dec-10 0:00 
QuestionError Can't serliase access for the transaction Pin
kjsl2k919-Dec-10 18:08
kjsl2k919-Dec-10 18:08 
AnswerRe: Error Can't serliase access for the transaction Pin
Jörgen Andersson20-Dec-10 10:29
professionalJörgen Andersson20-Dec-10 10:29 
QuestionSQL Server Memmory problem Pin
MAW3019-Dec-10 11:35
MAW3019-Dec-10 11:35 
AnswerRe: SQL Server Memmory problem Pin
Mycroft Holmes19-Dec-10 11:57
professionalMycroft Holmes19-Dec-10 11:57 
QuestionConnect C# Application to network Oracle 10g install Pin
PDTUM18-Dec-10 8:10
PDTUM18-Dec-10 8:10 
AnswerRe: Connect C# Application to network Oracle 10g install Pin
Mycroft Holmes18-Dec-10 12:21
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GeneralRe: Connect C# Application to network Oracle 10g install Pin
PDTUM18-Dec-10 13:57
PDTUM18-Dec-10 13:57 
AnswerRe: Connect C# Application to network Oracle 10g install Pin
Jörgen Andersson18-Dec-10 13:07
professionalJörgen Andersson18-Dec-10 13:07 
GeneralRe: Connect C# Application to network Oracle 10g install Pin
PDTUM18-Dec-10 13:55
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JokeRe: Connect C# Application to network Oracle 10g install Pin
Mycroft Holmes18-Dec-10 16:21
professionalMycroft Holmes18-Dec-10 16:21 
GeneralRe: Connect C# Application to network Oracle 10g install Pin
jschell19-Dec-10 9:57
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GeneralRe: Connect C# Application to network Oracle 10g install Pin
PDTUM19-Dec-10 10:39
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