2013 Community Moderator Election

The community moderator election is currently in the election phase.

Please cast your vote by May 28!

Top new questions this week:

Updating a table with millions of records, its been 4 days

I am currently updating a table with millions of records, its been 4 days and query is still executing. I checked the activity monitor its shows that query is running. In event log there is no …

sql sql-server sql-server-2008

asked by Lucky 9 votes answered by gbn 7 votes

Index Seek vs Index Scan

Looking at an execution plan of a slow running query and I noticed that some of the nodes are index seek and some of them are index scan. What is the difference between and index seek and an index …

sql-server sql-server-2005 performance index execution-plan

asked by Greg 7 votes answered by David Spillett 13 votes

Is there any way to prevent the memo structure from being pruned?

We know that the memo structure is pruned and some expensive alternative plans are discarded during optimization. I was wondering if there is any way to prevent this and let the optimizer just …

sql-server optimization

asked by Zhan Li 7 votes answered by Paul White 11 votes

How can a database be normalized when an optional field causes denormalization?

Suppose you have a warehouse full of widgets. Each widget in the warehouse is stored in a specific identifiable location within the warehouse. You might have a schema which looks like this: A …

database-design schema normalization

asked by Shawn McKnight 6 votes answered by Ken Gregory 2 votes

Dropping Hypothetical Indexes

In the past I thought I'd deleted hypothetical indexes using either a DROP INDEX statement for clustered indexes and DROP STATISTICS statement for non-clustered indexes. I have a database that is …

sql-server sql-server-2008 index database-tuning-advisor

asked by Gizmo 6 votes answered by Mike Sherrill 'Catcall' 0 votes

Is there any way to trace optimizer's work in MySQL?

Just like the MEMO structure in SQL Server which is kind of a "paper trail" of steps the optimizer takes in optimizing the query. Is there anything in MySQL through which I can get the information …

mysql sql optimizer

asked by Zhan Li 6 votes answered by ypercube 7 votes

Troubleshooting SOS_SCHEDULER_YIELD wait

Running our corporate ERP (Dynamics AX 2012), I noticed our production environment seemed much slower than our development systems. After performing the same activities in both the development and …

sql-server performance sql-server-2012 wait-types

asked by Nicholas Peterson 5 votes answered by Nicholas Peterson 2 votes

Greatest hits from previous weeks:

How do you mysqldump specific table(s)?

How can I dump a specific table or set of tables without including the rest of the db tables?

mysql backup mysqldump

asked by markdorison 20 votes answered by RolandoMySQLDBA 24 votes

How do I list all databases and tables using psql?

I am trying to learn PostgreSQL administration and have started learning how to use the psql command line tool. When I log in with psql --username=postgres, how do I list all databases and tables? I …

postgresql tools psql command-line

asked by Jonas 38 votes answered by Frank Heikens 49 votes

Can you answer these?

Failover only working for Classic ASP, not ASP.net

Setup: All machines run Windows Server 2008 Enterprise SQL Server 2012 Standard (Primary) SQL Server 2012 Standard (Mirror) SQL Server 2012 Express (Witness) Root issue: Our ASP.NET application is …

sql-server sql-server-2012 mirroring failover ado.net

asked by Adam 2 votes

Record versioning and promotion

Let's say we have this hierarchy: -World --USA ---WA ----Seattle -----Downtown ------1st Ave -------945 1st ave ------3rd Ave …

sql-server database-design sql-server-2008-r2

asked by user4079 1 vote

Troubleshooting a SQL Server instance that won't start

I've had a problem with one instance of SQL Server 2008 (the free version) not starting automatically. I always have to right click on the icon in the task bar and start it manually. It is set to …

sql-server sql-server-2008 configuration startup

asked by Nelluk 1 vote