The Query Optimiser needs a good estimate of the number of rows likely to be returned by each physical operator in order to select the best query plan from the most likely alternatives. Sometimes these estimates can go so wildly wrong as to result in a very slow query. Joe Sack shows how it can happen with SQL Queries on a data warehouse with a star schema.
This Friday we look forward to the various tech events of 2008 and which speakers you think are worth seeing. This editorial was originally published on Jan 11, 2008. It is being re-run as Steve is traveling.
Occasionally, when deploying a database, you need to copy data out to file from all the tables in a database. Phil Factor shows how to do it, and illustrates its use by copying an entire database from one server to another.
Steve Jones is recommending that you don't work the most efficient way at your job. Sometimes. This editorial was originally published on Apr 3, 2008. It is being re-run as Steve is out of town.
Red Gate won 8 awards in the recent SQL Server Pro annual product reviews. As a celebration, we're giving away a few prizes.
SQL Server 2012 Integration Services offers a wide range of powerful features that allow you to streamline and automate tasks involving data extraction, transformation, and loading. However, incorporating these features into your existing business intelligence framework frequently necessitates additional security measures ensuring that data which is being processed remains protected from unauthorized access.
As part of the LAMP stack, MySQL is incredibly important for providing a reliable and platform-agnostic database platform for web development. This level looks at the syntax of MySQL and how to best port SQL code to a MySQL environment.
Do personality types matter and did you know there are more than just A or B types? This editorial was originally published on Feb 26, 2008. It is being re-run as Steve is traveling.
I have a requirement to add the Log Shipping Monitor for an existing installation. I have heard you can only complete this by rebuilding the Log Shipping infrastructure. Is that true? Are there any other options? In this tip I will explain how we can add the Log Shipping monitor to a SQL Server 2005, 2008, 2008 R2 or 2012 environment without rebuilding the Log Shipping installation.
Defaults are important since so many people just accept them. Steve Jones thinks that SQL Server needs to add more defaults to the setup program that might help DBAs better manage their systems.
By Steve Jones
My life has some crazy travel stretches for sure. Between speaking, office visits, customer...
In Part 1, we saw how ‘Vamana’ represents vectors as nodes, connects them with...
I’m excited to announce the release of a new open-source project that fully automates...
Comments posted to this topic are about the item Server-Level Table sizes
Comments posted to this topic are about the item Optional Parameter Plan Optimization in...
There is a table tmp_tab:
CREATE TABLE tmp_tab ( id int, val int );
INSERT INTO tmp_tab VALUES (1, 1), (2, NULL), (3, 3), (4, 4), (5, 5);You want to order the rows ids by the following expression:
ISNULL(val, id) + 1Which of the following queries produces the expected ordering and why? (Select all correct) See possible answers