nvarchar(max) vs nvarchar(N)
MS SQL Server offers several data types for storing strings.
The most popular are nvarchar(N) (1 ≤ N ≤ 4000) and nvarchar(max), which allow storing Unicode-encoded string data.
Application developers often transfer their experience with the string type from programming languages like C# or Java to databases and automatically choose nvarchar(max), which can store strings up to 2GB.
However, databases store and process data in fundamentally different ways.
In this article, I will explain and demonstrate the consequences of unjustified use of the nvarchar(max) type.
List initializer
We all used to type new List<int> { 1, 2, 3, 4 } or new int[] { 1, 2, 3, 4} to initialize collections with some values. It looks similar in syntax but differs in behavior, and you should be careful if you are concerned about performance.
Harmful collection transformations. Part 3: collections
Starting with string in the first post we continue to study examples with collection transformations and how they affect our applications.
Harmful collection transformations. Part 2: automatic diagnostics
The previous post contains code examples that can be simplified by removing ToArray() or ToCharArray() calls. And an interesting example with List<char> constructor. But we need to be very attentive to find such places in our code. It would be much safer to do it automatically. This post shows us about automatic compiler diagnostics that can detect issues.
Harmful collection transformations. Part 1: string to array of chars
An array — the simplest collection. It's just a memory block with elements of one type. Arrays are often used when we need to iterate a collection, to search for elements or transform them. C# and .net evolved, many new collections were introduced, interfaces allowed to create generalized algorithms, LINQ simplified the work of programmers, but we continue to use arrays in inappropriate places and perform excess and sometimes harmful transformations. This post begins a series about collections, their features, performance and design. All posts will contain benchmarks, code examples, my opinion and recommendations.
I want to start with a string, some specific collection of .net.