Summary

In this chapter, we studied LINQ performance by benchmarking a variety of ways to query, group, filter, and iterate data obtained from databases and in-memory collections. The most performant way to query a database was found to be using the IEnumerator interface. By disassembling code, we saw that the let keyword can degrade performance due to the extra lines of IL code produced by the compiler. We also saw how accessing the last element in a collection using its index is faster than calling the Last() method. And we also learned that filtering lists by filtering on objects with the least items first improves filter performance operations. Closures provided better overall performance when passing in parameters, compared to not passing in parameters.

In the next chapter, we will be looking at file and stream I/O performance. But for now, see if you can answer the following questions, and check out the further reading material to solidify what you have learned in this chapter...