No indexes on small tables?

Question

\"We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil.\" (Donald Knuth). My SQL tables are unlikely to conta

Answer 1

Absolutely incorrect. 100% incorrect. Don't put a million pointless indexes, but you do want a Primary Key (in most cases), and you do want it CLUSTERED correctly.

Here's why:

SELECT * FROM MySmallTable <-- No worries... Index won't help

SELECT
    *
FROM
    MyBigTable INNER JOIN MySmallTable ON... <-- Ahh, now I'm glad I have my index.

Here's a good rule to go by.

"Since I have a TABLE, I'm likely going to want to query it at some time... If I'm going to query it, I'm likely going to do so in a consistent way..." <-- That's how you should index the table.

EDIT: I'm adding this line: If you have a concrete example in mind, I'll show you how to index it, and how much of a savings you'll get from doing so. Please supply a table, and an example of how you plan in using that table.