Question

I have this query

SELECT id FROM btn 
WHERE parentid =0
AND (mem_id =ANY(SELECT mem_id FROM network WHERE frd_id='401') || mem_id ='401')
ORDER BY btn.date DESC LIMIT 0,20

& this query

SELECT mem_id FROM net WHERE frd_id='401'

gives me result like this

mem_id
34
45
633
24
22

I want to optimize the above main query which is currently taking 46 second after scanning 13,373 records of btn table

Please suggest me hw can I optimize this query?

thnks

Answer 1

SELECT DISTINCT b.id FROM btn b
INNER JOIN network n ON (n.mem_id = b.mem_id)  
WHERE b.parentid = '0'
AND ('401' IN (n.frd_id, n.mem_id))
ORDER BY b.date DESC 
LIMIT 20 OFFSET 0

Make sure to have indexes on

btn.mem_id, btn.parentid, btn.date
network.mem_id, network.frd_id