Which is most efficient please

[barrypalmer]

I have a DB with 100K records
I need to pull out ONE records at a time for processing

I say SELECT * FROM table WHERE done=0 LIMIT 1;

Since the records have 30+ fields (some large) would it be better to say

SELECT id FROM table WHERE done=0 LIMIT 1;
and then do another SELECT * for this 'id'

Just thinking of mySQL holding all that data just to throw it all away again for the LIMIT 1

[amitpatel66]

I have a DB with 100K records
I need to pull out ONE records at a time for processing

I say SELECT * FROM table WHERE done=0 LIMIT 1;

Since the records have 30+ fields (some large) would it be better to say

SELECT id FROM table WHERE done=0 LIMIT 1;
and then do another SELECT * for this 'id'

Just thinking of mySQL holding all that data just to throw it all away again for the LIMIT 1

If you want all the columns data then say SELECT * FROM instaed of SELECT id FROM

[ronverdonk]

You did not state if you are using index. Use the EXPLAIN SELECT ... statement and compare the resource usage results. On that basis you can decide what query is most efficient.

Ronald