mysql - How make use of EXPLAIN keyword? I got the following result -


i did add explain keyword in front of query had no idea how use query optimization.

output looks : https://drive.google.com/file/d/0b070x_hytgdbr195rey3q0e3mvu/view?usp=sharing

first line -- table scan (see nulls , all)

2nd , 4th line -- index scan ("using index"), rather costly since 10k rows needed.

what not tell whether other index(es) more efficient. nor tell whether reformulating query help. please provide select can there, plus tie more things explain.

more links:
http://myxplain.net/
http://www.sitepoint.com/using-explain-to-write-better-mysql-queries/


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