Index all columns

Question

Knowing that an indexed column leads to a better performance, is it worthy to indexes all columns in all tables of the database? What are the advantages/disadvantages of such ap

Answer 1

Indexes take up space. And they take up time to create, rebuild, maintain, etc. So there's not a guaranteed return on performance for indexing just any old column. You should index the columns that give the performance for the operations you'll use. Indexes help reads, so if you're mostly reading, index columns that will be searched on, sorted by, or joined to other tables relationally. Otherwise, it's more expensive than what benefit you may see.