All Articles - SQL Authority with Pinal Dave

SQL SERVER – Performance: Do-it-Yourself Caching with Memcached vs. Automated Caching with SafePeak

March 18, 2014

We’ve all been reading a lot of articles that suggest adding a caching layer in front of a database is more efficient than hitting the database directly. Among different caching options there is Do-It-Yourself coding, using open source tools like Memcached, or using Velocity (part of the Microsoft AppFabric) or…

MySQL – Pattern Matching Comparison Using Regular Expressions with REGEXP

March 17, 2014

Pinal Dave

SQL, SQL Tips and Tricks

MySQL

MySQL supports pattern matching comparison using regular expressions with REGEXP keyword. In this post we will see how to use REGEXP in MySQL. We can use the patterns ^, $, | and sqaure braces to effectively match the values. Let us create the following table: CREATE TABLE items(item_id INT, item_description…

SQL SERVER – What is the Difference Between Latches and Locks

March 16, 2014

Pinal Dave

SQL, SQL Interview Questions and Answers, SQL Server, SQL Tips and Tricks

A very common question I often get in the email is “What is the difference between latches and locks?” The answer to this question is not an easy one. Here is a quick answer from the MS white paper. A page in SQL Server is 8KB and can store multiple…

SQL SERVER – Find Port SQL Server is Listening – Port SQL Server is Running

March 15, 2014

Pinal Dave

SQL, SQL Interview Questions and Answers, SQL Server, SQL Tips and Tricks

SQL Server Management Studio, SQL Stored Procedure

Here is one of the very common interview questions I often ask people – Q: What is the default Port SQL Server running on? A: 1433 for TCP/IP and 1434 for USD connection. I always get the correct answer for this question. However, when I ask a follow up question,…

SQL SERVER – Error – Resolution – Could not allocate space for object in database because the filegroup is full

March 14, 2014

Pinal Dave

SQL, SQL Server, SQL Tips and Tricks

SQL Error Messages

Just a day ago on my local box I received following error. Could not allocate space for object ‘<object_name>’ in database ‘<database_name>’ because the ‘PRIMARY’ filegroup is full. Create disk space by deleting unneeded files, dropping objects in the filegroup, adding additional files to the filegroup, or setting autogrowth on…

SQL SERVER – SSIS Data Flow Troubleshooting – Part1 – Notes from the Field #019

March 13, 2014

Pinal Dave

SQL, SQL Server, SQL Tips and Tricks

Notes from the Field, SQL Backup and Restore, SSIS

[Note from Pinal]: This is a new episode of Notes from the Field series. SQL Server Integration Service (SSIS) is one of the most key essential part of the entire Business Intelligence (BI) story. It is a platform for data integration and workflow applications. The tool may also be used…

MySQL – How to do Straight Join in MySQL?

March 12, 2014

Pinal Dave

SQL, SQL Tips and Tricks

MySQL

In an earlier post, we have learnt a new type of join called NATURAL JOIN supported in MySQL. In this post will see another type of join called STRAIGHT_JOIN. STRAIGHT_JOIN is actually an INNER JOIN but it forces the order in which data should be processed. As per MySQL’s documentation…

SQL Contest – Win Amazon Gift Cards – Learn How to Get Started with ClustrixDB

March 11, 2014

Pinal Dave

SQL, SQL Server, SQL Tips and Tricks

It has been a long time since we contest where we can learn something new and win something cool. I reached out to the good folks of Clustrix with the request to help me to build a contest where readers can learn and explore new technology, while stand a good…

MySQL – How to do Natural Join in MySQL? – A Key Difference Between Inner Join and Natural Join

March 10, 2014

Pinal Dave

SQL, SQL Tips and Tricks

MySQL, SQL Joins

As you know MySQL supports ANSI JOINs like INNER JOIN, OUTER JOIN, CROSS JOIN etc. Do you know that it supports NATURAL JOIN?. A NATURAL JOIN is a type of JOIN which automatically maps the similar columns from both the tables. Let us create the following tables CREATE TABLE items(item_id…

MySQL – Reset Row Number for Each Group – Partition By Row Number

March 9, 2014

Pinal Dave

SQL, SQL Tips and Tricks

MySQL, Ranking Functions

In earlier post, we have learnt how to generate row number for each row using a variable as MySQL does not have any system function like SQLServer’s row_number() to generate the row number. In this post we will see how to reset row number for each group (Alternate method for…