Indexing is most certainly the number one feature that can boost performance in a database system, and if used correctly, it can simplify even the most complex queries.
But, what exactly is a database index? A database index is a data structure aimed at improving the performance of read queries at the cost of decreasing the performance of write queries and increasing the storage space required by the data.
As a metaphor, we can say that a database index is similar to a book's index Instead of looking through the entire book, the database takes a shortcut and uses an ordered list that points to the correct content, resulting in the queries that are the orders of magnitude faster.
When you interact with a database, you don't have to use an index; although, it is strongly recommended. A query that doesn't make use of an index is called a full table scan, which means that the database has to go through the entire table to find the query result. This process is basically similar...