SQL-complete-tutorial

1
EXPLAIN SELECT customer_id, state FROM customers
2
ORDER BY state;
3

4
/* TIP: When creating indexes, look at your WHERE, ORDER BY and SELECT
5
clauses and try to include those columns in indexes as well. It will secure
6
more optimized search for indexes' purposes. */
7

8
-- INDEX MAINTENANCE
9
-- Duplicate Indexes -> double indexes created on the same columns (A, B, C)
10
-- Redundant Indexes -> when we have indexes on (A, B) and only on column A, but not on (B, A).
11
-- Before creating new indexes, check the existing ones and make sure to drop duplicate, 
12
-- redundant as well as unused indexes;