Remove DatabaseSnapshotBaseName Parameter In SqlServerDsc

This article discusses the proposal to remove the DatabaseSnapshotBaseName parameter from the Set-SqlDscDatabaseProperty cmdlet within the SqlServerDsc module. This parameter is specifically used during the creation of database snapshots and isn't intended for modifying properties of existing databases at runtime. This document outlines the reasoning behind this decision, the proposed solution, and the technical details involved.

Description

The DatabaseSnapshotBaseName parameter within the Set-SqlDscDatabaseProperty cmdlet is designed for a very specific purpose: specifying the base name when creating a database snapshot. It's not designed to be a property that you would modify after the database snapshot has been created. Its inclusion in Set-SqlDscDatabaseProperty is misleading because it suggests that you can use this cmdlet to modify the base name of an existing database snapshot, which is not the case. This can lead to confusion and potentially incorrect usage of the cmdlet. Therefore, to streamline the functionality and improve clarity, a decision has been made to remove it from the Set-SqlDscDatabaseProperty cmdlet. By removing this parameter, we are ensuring that users understand the intended use of the cmdlet and avoid any potential misuse. This change aligns with the principle of keeping cmdlets focused on their core responsibilities and preventing them from becoming overloaded with features that are better handled elsewhere.

Furthermore, the presence of DatabaseSnapshotBaseName in Set-SqlDscDatabaseProperty implies that it's a runtime-mutable property, which is incorrect. Database snapshots are created with a specific base name, and this name isn't meant to be changed after the snapshot is created. Trying to use Set-SqlDscDatabaseProperty to modify this property would not yield the desired results and could lead to unexpected behavior. Therefore, removing this parameter clarifies that database snapshot base names are set during creation and are not intended to be modified afterward. This change will enhance the user experience by providing a more accurate representation of the cmdlet's capabilities and limitations. By ensuring that the cmdlet's parameters accurately reflect its functionality, we are reducing the likelihood of errors and improving the overall usability of the SqlServerDsc module. The removal of DatabaseSnapshotBaseName from Set-SqlDscDatabaseProperty is a step towards making the module more intuitive and easier to use.

Proposed Solution

To address the issues associated with the DatabaseSnapshotBaseName parameter, a multi-faceted solution is proposed to ensure clarity and maintain functionality within the SqlServerDsc module. The core of the solution involves removing the misleading parameter and providing alternative methods for database snapshot creation.

Removing the DatabaseSnapshotBaseName Parameter

The first step is to remove the DatabaseSnapshotBaseName parameter from the Set-SqlDscDatabaseProperty cmdlet. This eliminates the confusion and prevents users from attempting to use the cmdlet to modify a property that is not intended to be changed after snapshot creation. This change simplifies the cmdlet's interface and makes its purpose more apparent.

Documenting Snapshot Creation Methods

Comprehensive documentation will be provided to guide users on how to properly create database snapshots. This documentation will emphasize the use of dedicated snapshot creation commands or T-SQL CREATE DATABASE ... AS SNAPSHOT OF statements. The documentation should provide clear examples and explanations of each method, ensuring that users can easily create snapshots according to their specific needs. This documentation will be readily accessible and easily searchable, allowing users to quickly find the information they need to create database snapshots effectively.

Creating a Dedicated New-SqlDscDatabaseSnapshot Command

If there is a need for a dedicated cmdlet to handle database snapshot creation within the SqlServerDsc module, a new cmdlet called New-SqlDscDatabaseSnapshot should be created. This cmdlet would be specifically designed for creating database snapshots and would include parameters relevant to the creation process, such as the base name and source database. This dedicated cmdlet would provide a clear and focused interface for creating snapshots, separate from the general-purpose Set-SqlDscDatabaseProperty cmdlet. This approach would improve the overall organization and usability of the SqlServerDsc module, making it easier for users to find and use the appropriate tools for their tasks.

References

This proposal is informed by the following references, which provide context and justification for the proposed changes:

• Related to issue #2177: This issue highlights the problems and confusion caused by the DatabaseSnapshotBaseName parameter in Set-SqlDscDatabaseProperty.
• Identified in PR #2327: https://github.com/dsccommunity/SqlServerDsc/pull/2327#discussion_r2469369032: This pull request discussion provides further insights into the rationale for removing the parameter.
• DatabaseSnapshotBaseName is set on the snapshot Database object before calling Create(), not via Alter(): This technical detail confirms that the parameter is only relevant during snapshot creation and not for modifying existing databases.

Technical Details

The following technical details further support the decision to remove the DatabaseSnapshotBaseName parameter from Set-SqlDscDatabaseProperty:

• Property: Database.DatabaseSnapshotBaseName
• Usage: Set when creating a snapshot, not for modifying existing databases

These details highlight that the DatabaseSnapshotBaseName property is specifically used when creating a database snapshot and is not intended for modifying existing databases. This confirms that the parameter's presence in Set-SqlDscDatabaseProperty is misleading and should be removed.

Conclusion:

Removing the DatabaseSnapshotBaseName parameter from Set-SqlDscDatabaseProperty is a necessary step to improve the clarity and usability of the SqlServerDsc module. By removing this parameter and providing alternative methods for database snapshot creation, we are ensuring that users can effectively manage their SQL Server environments. This change will enhance the user experience and reduce the likelihood of errors. For additional information on SQL Server database snapshots, you can refer to the official Microsoft documentation: SQL Server Database Snapshots.