Gerald Britton

Recursive CTEs and Foreign Key References in SQL Server

May 16, 2018 by

Introduction

Foreign key constraints are a powerful mechanism for preserving referential integrity in a database. They can also represent a challenge when doing bulk table loads, since you need to find a “base” table to start with – that is, a table that has no foreign key constraints defined. Let’s label tables like this as level 0, or ground level if you like. Once that is loaded, you can begin to load other tables that have foreign key references to the base table. We can label those tables level 1, and so on. If you start with table data that already has referentially integrity and load tables by their level numbers — level 0, level 1, level 2 and so on – the load should proceed without problems. Let’s look at a simple example:

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Ben Richardson

Understanding SQL Server’s TRY_PARSE and TRY_CONVERT functions

May 16, 2018 by

Data conversion is one of the most fundamental tasks of any programming language. Data received from different sources is often not in the right format. For example, if you receive an XML file where age is in the string format and you want to calculate an average age for the people in the file you will need to convert age into an integer.

To make the conversion process simple, the TRY_PARSE and TRY_CONVERT functions were introduced in SQL Server 2012. Before TRY_PARSE and TRY_CONVERT, SQL Server only had the PARSE and CONVERT functions.

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Nikhilesh Patel

The HashBytes function in T-SQL

May 16, 2018 by

One of the paramount ways to guard data within a database is to utilize database encryption. However, no one encryption solution is perfect for all databases. Which encryption solution you select totally depends on the requirements of your application. Note that more powerful encryption for larger amounts of data requires a healthy amount of CPU. So, be prepared in the event that that introduction of encryption increases the system load.

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Timothy Smith

Logging SQL Server database errors

May 15, 2018 by

We receive many database alerts with many of the alerts logging some of these same alerts or information to files or tables. What we’ve found over time is that the logging is now costing us quite a bit of resource. Our logging server (where both files and table logging are stored) has had a few outages related to conflicts from messages for other servers. We’ve considered scaling the alerting by environment type, but we’ve also considered that we may be logging too much information about our databases. In addition, since we receive so many alerts each day, it’s impossible for us to resolve them and assist with other issues that arise. What are some techniques that we can use to help us with the issue of too much logging information and too many alerts? Read more »

Dejan Sarka

Data science, data understanding and preparation – entropy of a discrete variable

May 14, 2018 by

In the conclusion of my last article, Data science, data understanding and preparation – binning a continuous variable, I wrote something about preserving the information when you bin a continuous variable to bins with an equal number of cases. I am explaining this sentence in this article you are currently reading. I will show you how to calculate the information stored in a discrete variable by explaining the measure for the information, namely the entropy.

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Prashanth Jayaram

Smart database backups in SQL Server 2017

May 14, 2018 by

So far, we’ve discussed several phases of backup that starts with planning, creating, strategizing and implementing. In this article, we are going to see how database administrators can define the strategy to improve backup performance and efficiently manage backups in SQL Server 2017. The following are the topics of discussion:

  1. Discuss checkpoints
  2. Discuss the enhancements made in the Dynamic Management View (DMV) sys.dm_db_file_space_usage for smart differential backups
  3. Discuss the enhancements made for the Dynamic Management function (DMF) sys.dm_db_log_stats  for smart transactional log backup
  4. Understand the functioning of smart differential backup and its internals
  5. Understand the Smart transaction log backup process and its internals
  6. T-SQL scripts
  7. And more…
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Timothy Smith

Reading file data with PowerShell

May 10, 2018 by

We have some custom files that we receive from different providers and for these situations we are unable to use standard ETL programs without any customization. Since we’re expanding our ability to read these custom files with .NET, we’re looking for efficient ways to read files with PowerShell that we can use in SQL Server Job Agents, Windows Task Schedulers, or with our custom program, which can execute PowerShell scripts. We have many tools for parsing data and wanted to know efficient ways of reading the data for parsing, along with getting specific lines of data from files by number, or by the first or last line of the file. For reading files efficiently, what are some functions or libraries we can use?

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Ahmad Yaseen

Working with different SQL Server indexes types

May 8, 2018 by

In the previous articles of this series (see the full article TOC at bottom), we discussed the internal structure of both SQL Server tables and indexes, the main guidelines that you can follow to design a proper index, the list of operations that can be performed on the SQL Server indexes, and finally how to design effective Clustered and Non-clustered indexes that the SQL Server Query Optimizer will always take benefits from, in speeding up the data retrieval process, which is the main goal of creating an index. In this article, we will go through the different types of SQL Server indexes, above and beyond Clustered and Non-clustered indexes classification, and when to use them.

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Prashanth Jayaram

SqlPackage.exe – Automate SQL Server Database Restoration using bacpac with PowerShell or Batch techniques

May 7, 2018 by

Data is the key to your organization’s future, but if it’s outdated, irrelevant, or hidden then it’s no good. Maintenance and administration of databases takes a lot of work. As database administrators, we often tend to automate most of these repetitive tasks. A database refresh is one of the most common tasks performed by most of the administrators as part of their daily routine.

Today, database refreshes are quite frequent because of Continuous Integration (CI) and Continuous Deployment (CD). In most of the cases, testing requires a separate but current production dataset to ensure the validity of the desired result.

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Ahmad Yaseen

Designing effective SQL Server non-clustered indexes

May 7, 2018 by

In the previous articles of this series (see below for the full index of articles), we went through the internal structure of SQL Server tables and indexes, listed a number of guidelines that help in designing a proper index, discussed the operations that can be performed on SQL Server indexes and finally showed how to design and create a SQL Server Clustered index to speed up data retrieval operations. In this article, we will see how to design an effective Non-clustered index that will improve the performance of frequently used queries that are not covered with a Clustered index and, in doing so, enhance the overall system performance.

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Prashanth Jayaram

Understanding Database snapshots vs Database backups in SQL Server

May 4, 2018 by

In the article, we’ll walk through the concepts to understand database snapshots, and their benefits and limitations. This article will help you decide when to use a database snapshot, and when to use a backup. In some cases, the database relying on database backup and restoration operation is not a viable option. Let’s dig into the concepts of database snapshots and see how it differs from a database backup.

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Esat Erkec

How to integrate Power BI to the Facebook Graph API

May 4, 2018 by

The challenge

With the popularity of social networking and sharing sites and their widespread availability, internet marketing techniques have also been rapidly influenced. Sharing sites with high visitor traffic offers great potential for advertisers, so much so that it is almost unheard of now that brands or products do not have a profile or group on a social networking site. Markets have the opportunity to communicate directly with consumers by creating profiles or groups in sharing sites. Thanks to the comments and forums on the pages, they are able to follow both positive and negative attitudes of the target groups about themselves and thus have more precise ideas about what to do next.

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Thomas Mattei

Logical SQL Server data replication 101

May 4, 2018 by

Introduction

Data replication has been around for many decades. There are two primary types of data replication, logical and physical. This article covers a high-level view of logical replication, the differences between logical and physical replication and the specifics of SQL Server transactional replication.

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Sifiso W. Ndlovu

How to use Microsoft Flow to extract SharePoint Online list data

May 3, 2018 by

Data extraction is a pivotal part of any business process particularly when it comes to running reports and facilitating business decision-making. In the article, How to configure OData SSIS Connection for SharePoint Online, I covered data extraction off a SharePoint Online list using SQL Server Integration Services (SSIS). You would have noticed in the aforementioned article that getting SSIS to successfully integrate with SharePoint Online lists can be a laborious exercise, especially if you haven’t installed the correct SharePoint SDK files. Thus, in business environments where business and Power Users have more control of data extraction processes, SSIS could get complicated for an ordinary business user to operate. Therefore, given the nature of our source data and the platform in which it resides, ETL architects and developers alike may need to find alternative ETL tools to SSIS. This brings me to Microsoft Flow which could be one possible alternative to using SSIS for data extraction. Microsoft Flow is part of Office 365 applications and just like SharePoint Online, is a cloud-based application that is freely available, easier to operate and effortlessly integrates with – amongst other applications – SharePoint Online. The aim of this article is to demonstrate the convenience of extracting data from one SharePoint Online list to another using Microsoft Flow.

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Prashanth Jayaram

Discussing Backup and Restore Automation using SQLCMD and SQL Server agent

May 3, 2018 by

Database administrators are often requested to refresh a database, mostly to create a live copy of the production database to the test or development environment. This is done so that the development or the test environment closely resembles the production environment; this way, we prevent many undesirable issues when running the application in the production environment.

Many developers, at times, are required to write and debug code on the production copy of the database, so it makes more sense to refresh the database on regular basis.

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Ahmad Yaseen

Designing effective SQL Server clustered indexes

May 3, 2018 by

In the previous articles of this series (see bottom for a full index), we described, in detail, the structure of SQL Server tables and indexes, the basics and guidelines that help us in designing a proper index and finally the list of operations that can be performed on the SQL Server indexes. In this article, we will see how we could design an effective clustered index that the SQL Server Query Optimizer will always take benefits from, in speeding up the data retrieval process, which is the main goal of building an index.

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