Question

This is the table structure:

for_id
from_id
for_folder
from_folder
deleted

The number 2 represents my ID and this is the query:

SELECT *
FROM poruke_konverzacija
WHERE (
(
for_id =2
AND for_folder = "inbox"
)
OR (
from_id =2
AND from_folder = "inbox"
)
)
AND deleted !=2

I have near 500k records on that table and when i run explain, this is what i get:

id  select_type  table  type  possible_keys  key  key_len  ref  rows  Extra
1  SIMPLE  poruke_konverzacija  ALL  obrisano,za_id,od_id  NULL  NULL  NULL  456884  Using where; Using filesort

I have indexed for_id from_id for_folder from_folder and the query is really slow. Is there any other way to do so and get the same results ?

Answer 1

Index deleted also. As well…A union may be better, running two concurrent queries rather than one long one..

Additionally indexing/selecting on string fields is always slower. If you can make a look up table for the folders

ie

id ----- folder
1        inbox
2        sent
3        trash

in your poruke_konverzacija table convert the from_folder and for_folder to the equivalent ID

SELECT *
FROM poruke_konverzacija
WHERE
for_id =2
AND for_folder = "inbox"
AND deleted !=2
UNION
SELECT *
FROM poruke_konverzacija
WHERE
from_id =2
AND from_folder = "inbox"
AND deleted!=2