The problems caused by the SQL Sapphire Worm, also know as the SQL Slammer, have caused many sites to do a quick upgrade to SQL Server 2000 Service Pack 3 (SP3). It includes the fix that prevents infection by the worm. While moving to the latest service pack is usually a good thing, to do so without thorough testing risks breaking a working application. That is exactly what happened to one of my clients over the weekend.
2005-11-02
2,068 reads
You can just hear it now: At the table down the hall, there’s a group of people having, (as it seems to you) yet another academic discussion on the merits of third-normal form and the structure of primary keys. You’ve heard many discussions like this before — it all seems so pointless. After all, doesn’t it just boil down to “create table” commands and a bunch of DDL? You mastered all that in your first DBA class. What could be so hard?
2005-10-31
3,688 reads
Right out of the box, SQL Server 2005 does not install many of its services (such as SQL Server Reporting Services) or does not have features turned on by default (.NET integration), thereby reducing the attack vectors that hackers could use to compromise your data security.
2005-10-27
2,024 reads
Check digits–not to be confused with checksums–are often added to numeric identifiers such as customer and product numbers to reduce the chance of incorrect entries. Sequences of numbers are notoriously easy to mistype, and constraints alone generally won't do the job. In this excellent article, Lynn Fields shows you how to implement the "Cadillac" of check digit methods–the Verhoeff Dihedral Group.
2005-10-26
2,735 reads
One of the most difficult database operations to scale-up on high-end server systems is the network call. In fact, without special precautions, a high call volume database application can have severe negative scaling on large systems. It is suspected that this problem is more pronounced on NUMA systems than basic SMP systems. A NUMA system with 16 processors can have significantly lower throughput capability than an otherwise comparable 4-way SMP system.
2005-10-25
1,754 reads
There is an important technique for creating truly agile databases that I haven’t seen in his writings; one which is well-known to DBAs, but little understood in the application development community – the use of database views to create a layer of abstraction between the normalized relational tables and the applications that use the data.
2005-10-21
3,736 reads
In this article, I will introduce a significant improvement that underlies the new Analysis Services development approach, the Data Source View. A Data Source View is a design-time object that makes its home in the workbench environment of the Business Intelligence Development Studio.
2005-10-20
2,655 reads
SQL Server Profiler can correlate Microsoft Windows System Monitor (Performance Monitor in Windows NT 4.0) counters with SQL Server or SQL Server 2005 Analysis Services (SSAS) events. Windows System Monitor logs system activity for specified counters in performance logs. The first thing to remember is in order to have correlating information you need to obviously be in sync - in other words you must start the perfmon trace and profiler trace at the same time or else they won't match up.
2005-10-19
2,508 reads
Database geeks are all around us. I met Gary Mallow on the email list of a cycling group run by a local church. After some conversation, I discovered that he is a director of a group of developers who build applications, sometimes using .NET and often using Oracle as a database. Like me, Gary is not entirely comfortable with his ability as a UI developer, and so finds database work a good fit.
2005-10-18
1,689 reads
In the preceding articles of this series, Lock Granularity, Transactions, and ACID were introduced. Common lock types, such as Shared, Exclusive, and Update were explored, as well as using SP_Lock to obtain current system lock information. In this article, the normal internal SQL locking methods will be manipulated using Lock Hints in order to obtain finer lock control.
2005-10-14
4,123 reads
I’ve been thinking a lot lately about what it actually takes to make an...
By Steve Jones
Redgate is a for-profit company. We look to make money by building and selling...
I’ve uploaded the slides for my Techorama session Microsoft Fabric for Dummies and my...
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We create the following table and then insert some records in it:
create table t1 ( id int primary key, category char(1) not null, product varchar(50) ); insert into t1 values (1, 'A', 'Product 1'), (2, 'A', 'Product 2'), (3, 'A', 'Product 3'), (4, 'B', 'Product 4'), (5, 'B', 'Product 5');What happens if we execute the following query in both Sql Server and PostgreSQL?
select id,
category,
string_agg(product, ';')
over (partition by category order by id
rows between unbounded preceding and unbounded following) as stragg
from t1; See possible answers