Big Data is constantly in the news. We've been asked at SQLserverCentral to try and develop some articles, perhaps even a stairway to explain what Big Data is and how we might use it. I'm still trying to grasp the concepts myself, and unlike the amorphous cloud, I'm still looking for some good examples of what Big Data really is.
When I ran across this piece warning that Big Data isn't the final solution to all our questions in the world, I wasn't surprised. The piece notes that Google Flu hasn't been very accurate in its predictions of outbreaks. At first glance, this gives lots of credence to the idea that the good, solid data analysis and mining techniques we've used for years are just as good as any new Big Data fad.
However as I read more about the piece, it's not that big data and the analysis of large quantities of information is flawed, it's that a solid hypothesis matters. Researchers need to be willing to evolve their algorithms as they learn more about a problem. Probably they should also assume their algorithms are not correct until they've proven their ability to predict actual trends for some period of time.
We'll constantly be searching for ways to better interpret information and make better decisions. No new technology or product is going to magically solve our problems. Good solid understanding of the problem domain will continue to matter as much as the data itself.
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There are times where you need to write a single T-SQL statement that is able to return different T-SQL expressions based on the evaluation of another expression. When you need this kind of functionality you can use the CASE expression or IIF function to meet this requirement. In this Stairway level Gregory Larsen reviews the CASE and IIF syntax and showing you examples of how the CASE expression and IIF function. More »
If you have been in the information technology industry long enough, you have probably heard the expression "this adds overhead" when discussing any extra processing added on to what is considered normal processing. Dallas Snider answers the question of additional overhead caused by encryption. More »
One of the most common wait types you will see on a SQL Server is the CXPACKET wait type.
This... More »
Question of the Day
Today's Question (by Joe Barth):
Okay, you need Adventureworks, on a instance you don't care about or you will want to wrap the deletes in a transaction and rollback.
Run statement one:
SELECT TOP 10 'DELETE FROM [AdventureWorks2012].[Person].[BusinessEntityAddress] ' + CHAR(13) + 'WHERE [BusinessEntityID]='+CAST([BusinessEntityID] AS VARCHAR(50))+ CHAR(13) + 'GO'
Run statement two:
SELECT TOP 10 'DELETE FROM [AdventureWorks2012].[Person].[BusinessEntityAddress] ' + CHAR(13) + 'WHERE [BusinessEntityID]='+CAST([BusinessEntityID] AS VARCHAR(50))+ CHAR(10) + 'GO'
When you copy the results and paste in a new SSMS query window, which Deletes will successfully execute?
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Securing SQL Server - Written by Denny Cherry, a Microsoft MVP for the SQL Server product, a Microsoft Certified Master for SQL Server 2008, and one of the biggest names in SQL Server today, Securing SQL Server, Second Edition explores the potential attack vectors someone can use to break into your SQL Server database as well as how to protect your database from these attacks. In this book, you will learn how to properly secure your database from both internal and external threats using best practices and specific tricks the author uses in his role as an independent consultant while working on some of the largest and most complex SQL Server installations in the world. This edition includes new chapters on Analysis Services, Reporting Services, and Storage Area Network Security.
You are using a symmetric key to encrypt some data in a stored procedure. However you want to follow good coding practices and stop using the key when you are done with the encryption before you execute other code. What T-SQL would you use to ensure that the symmetric key, SalesSymKey, cannot be used later in your session?
Answer: CLOSE SYMMETRIC KEY SalesSymKey
The correct answer is the CLOSE SYMMETRIC KEY T-SQL command. This will prevent the key from being used later in your session for another purpose unless it is opened.
I would like to share my experience on how to find out dependencies between a table's field name and stored procedures or functions.
I often encounter situations that require database schema changes to meet business requirement changes. For example, changing the name for some fields. It might be an easy thing if the database is small and not used for a complex front-end. However, in my cases, changing a field's name often means:
table schema change
stored procedures change
data access layer code change
data presentation layer code change
At least the first three are in the SQL scope, and it would be time consuming if we have to open each stored procedure or function and search from there.
This script is not complicated but rather a handy tool. It will list all the stored procedures and functions that contains the given keyword passed as a parameter, and will further indicate if the keyword is actually used as a parameter. This is important because it helps me to find out what functions are related to it in my data access layer code.
There are some limitations:
All my stored procedures start with sp or dd, so you should modify the script to meet your own situation.
All my stored procedures are no longer than 3000 characters, so if you have a longer one, please increase the parameter in the script.
Keyword length is set to varchar(20). You can increase it by modifying the script if you want to search for a longer keyword.
CHAR column concenation
- Hey gang,
I'm a little stumped here. I want to concatenate character data from a table.
[code="sql"]declare @ttest table
(nItem integer not null,
ctext varchar(32) not null)
Need Query for summarizing data
- Hi there,
I need query for the attached output
create table #Wholeseller ( wsid varchar(100),[Productid From] int, [Productid To] int, units int)
create table #Retailer ( retid...
Need assistance with XML
- Hello all,
I have a table which contains an XML column. This column is set up as "<properties><propertyName1>Value1</propertyName1><propertyName2>Value2</propertyName2>" etc...
I also have...
- After seeing this: [url]http://www.sqlservercentral.com/Forums/Topic1546354-391-1.aspx[/url]
I'd like to see some articles that look at real situations where you've replaced a cursor (or...
T-SQL Comparing Rates
- A writeup based on this thread. Show how this works and why one method may be better than the other
Export with Headers
- How can you export data from a query, using bcp, SQLCMD, etc. and include the column headers at the top?...
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