In multi-user database environments, ensuring the integrity and consistency of data is essential. One common challenge is preventing multiple instances of the same stored procedure from executing at the same time, which can lead to data conflicts, race conditions, and unpredictable results. To address this, SQL Server provides a powerful tool called sp_getapplock. This post explains what sp_getapplock is, what you are actually locking when you use it, how to implement it to prevent concurrent executions of a stored procedure, and the difference between transaction-level and session-level locks.
Category: Data Integrity
Exploring Programming Constructs in T-SQL – Part 3: Error Handling and Transaction Management
Welcome back to our series on programming constructs in T-SQL! In the previous installments, we explored variables, conditional IF statements, loops, and CASE expressions. These tools have helped us write dynamic and efficient SQL scripts. In this third part, we’ll focus on two essential concepts for writing reliable SQL code: Error Handling with TRY…CATCH Blocks and Transaction Management.
Understanding SQL Server’s TRUSTWORTHY Database Setting
In SQL Server, the TRUSTWORTHY database setting can grant elevated permissions across a database boundary, influencing how certain modules execute, particularly those using WITH EXECUTE AS or unsafe CLR assemblies. Enabling TRUSTWORTHY allows SQL Server to “trust” that the database owner and associated users won’t misuse elevated permissions to perform unauthorized actions. However, this setting comes with significant security risks if used improperly.
Using TRUNCATE TABLE with Table Partitions in SQL Server
In SQL Server, the TRUNCATE TABLE command is often favored over DELETE for its efficiency when removing data from a table. However, when working with partitioned tables, the locking behavior changes slightly. Additionally, the LOCK_ESCALATION = AUTO setting can further optimize performance by managing lock escalation at the partition level. We explore how these features interact, providing an in-depth look at locking behavior when truncating partitioned tables and the role of LOCK_ESCALATION = AUTO.
Five More SQL Server Error Log Messages You Should Care About
In a previous post, we explored five significant SQL Server error log messages that demand immediate attention. However, the SQL Server error log contains a wealth of additional information essential for maintaining the health and performance of your databases. In this sequel, we will highlight five more error log messages that should be on your radar. We’ll look into what each error means and offer suggestions for when you encounter them.
Manually Synchronizing a Lagging Secondary Replica in SQL Server Always On Availability Groups
In high-availability environments, SQL Server Always On Availability Groups (AG) are essential for minimizing downtime and preventing data loss. However, situations can arise where a secondary replica lags behind the primary, disrupting synchronization and risking potential data inconsistencies. This blog provides instructions on how to manually catch up a lagging secondary replica using transaction log backups.
Securing NorthPine Bank’s Data: How SQL Server 2022 Can Help
NorthPine Bank, a fictitious yet representative financial institution, recognized the necessity to modernize its data infrastructure to safeguard sensitive customer information against emerging threats. The bank decided to migrate its operations to SQL Server 2022, leveraging its advanced security features to enhance data protection, ensure regulatory compliance, and maintain operational efficiency. This blog explores the specific security challenges faced by NorthPine Bank and details how SQL Server 2022 addresses these issues through its robust, built-in features.
The Hidden Layers of Dynamic Data Masking in SQL Server
Dynamic Data Masking (DDM) in SQL Server is a feature that helps prevent unauthorized access to sensitive data by obfuscating it at the display level. This blog post discusses the various types of masks available, such as default, email, custom string, and random masks. We explore permissions and access control, demonstrating how users can modify masked data without viewing its actual content. Additionally, we discuss the new permission enhancements in SQL Server 2022 that allow for more granular control over unmasked data.
Managing SQL Server Database Growth with Files and Filegroups
As SQL Server databases expand over time, managing their growth becomes an important task. If not handled properly, this growth can lead to performance issues and maintenance headaches. One effective way to manage database growth is by using filegroups and data files thoughtfully. With proper planning, you can distribute your data across different storage devices, enhance performance, and keep your database scalable.
Managing IDENTITY and SEQUENCE Behavior in SQL Server Always On Availability Groups
In SQL Server Always On Availability Groups, maintaining data consistency during failovers is necessary for high availability and reliability. However, certain aspects of database behavior, such as the generation of values by IDENTITY columns and SEQUENCE objects, can lead to unexpected gaps or jumps after a failover or server restart. This can affect the continuity of sequential values, which is often important in business applications. In this post, we’ll look into how SQL Server handles IDENTITY columns and SEQUENCE objects in an Always On environment, explain the role of caching, and offer strategies to manage or prevent gaps in your sequences during failovers.