I’ve experienced this first hand but I’m having a hard time locating any resources on the subject after several Google searches:
SELECT * FROM Table LIMIT x
has a slower return time than explicitly listing all of a specific table’s column names:
SELECT id, name, email, address, phone, sex, date, ip FROM Table LIMIT x
What is the reason for this?
(assuming you are Explicitly Selecting all the column names, i.e., the table contains only columns id, name, email, address, phone, sex, date, ip)
When you do
select *the rdbms has to expand the*to the column names and do the select after words. When you provide explicit column names that step isnt necessary.