4. B-Tree index structure
In the relational database, the B-tree index is the most common and one of the most commonly used index types. Although the specific implementation details of the B-tree index in each relational database are different, many aspects are similar and interlinked. The data of the B-tree index is logically ordered. It is precisely because the B-tree index has this important feature that we can use it to greatly improve the efficiency and performance of data access. In many real-life scenarios, we can not only use B-tree index to accurately locate and search related data; at the same time, we can also use B-tree index to avoid sorting related data. These are commonly used and often effective in our daily work. Very obvious means of optimization. However, in some scenarios, the purpose of improving performance and avoiding sorting may not be achieved through B-tree indexing. Therefore, on the premise of understanding the principle and mechanism of B-tree indexing, apply B-tree flexibly, reasonably and correctly according to specific scenarios Indexes are critical.
In SQL Server , clustered index and non-clustered index are the most common and commonly used B-tree indexes. Both have been introduced in detail in the previous article, so I won’t repeat them here. Below, we will only explain and discuss in detail the internal structure and implementation details of the two. This is also to use the B-tree index to efficiently tune and optimize the database, and then manage and apply the B-tree reasonably, scientifically and correctly. The premise, core and essence of indexing.