Reduce the execution time in postgresql - postgresql

Question

Here I attached my query. It's getting 60141 ms to execute. I don't know what should i do. But I want to execute in short time.And now I posted my analyze and execute output of my query. Please help on this.
EXPLAIN (BUFFERS,ANALYZE) SELECT id
FROM activitylog
WHERE (url = '/staff/save/117' OR url = '/staff/create/117')
AND timestamp > '1990-01-01 00:00:00'
AND userid IN ( SELECT id
FROM users
WHERE companyid = ( SELECT companyid
FROM users
WHERE id='150' ) )
ORDER BY timestamp DESC
Output:
Sort (cost=934879.83..934879.83 rows=1 width=12) (actual time=63918.947..63918.948 rows=4 loops=1)
Sort Key: activitylog."timestamp"
Sort Method: quicksort Memory: 25kB
Buffers: shared hit=168161 read=561433
InitPlan 1 (returns $0)
-> Index Scan using "usersPrimary" on users users_1 (cost=0.14..8.16 rows=1 width=4) (actual time=0.005..0.005 rows=1 loops=1)
Index Cond: (id = 150)
Buffers: shared hit=2
-> Nested Loop (cost=0.00..934871.66 rows=1 width=12) (actual time=63918.693..63918.917 rows=4 loops=1)
Join Filter: (activitylog.userid = users.id)
Rows Removed by Join Filter: 400
Buffers: shared hit=168158 read=561433
-> Seq Scan on users (cost=0.00..10.53 rows=25 width=4) (actual time=0.018..0.085 rows=101 loops=1)
Filter: (companyid = $0)
Rows Removed by Filter: 114
Buffers: shared hit=10
-> Materialize (cost=0.00..934860.39 rows=2 width=16) (actual time=120.024..632.858 rows=4 loops=101)
Buffers: shared hit=168148 read=561433
-> Seq Scan on activitylog (cost=0.00..934860.38 rows=2 width=16) (actual time=12122.376..63918.564 rows=4 loops=1)
Filter: (("timestamp" > '2019-01-02 19:19:12.649837+00'::timestamp with time zone) AND (((url)::text = '/jobs/save/81924'::text) OR ((url)::text = '/jobs/create/81924'::text)))
Rows Removed by Filter: 11935833
Buffers: shared hit=168148 read=561433
Planning time: 0.806 ms
Execution time: 63919.748 ms
Thanks In advance.

Answer 1

Try this one, Join query will enhance the indexing and optimized query execution time
SELECT id
FROM activitylog
WHERE url in ('/staff/save/117','/staff/create/117')
AND TIMESTAMP > '1990-01-01 00:00:00'
AND EXISTS
(SELECT 1
FROM users AS u
JOIN users ur ON ur.CompanyID = u.CompanyID
WHERE ur.ID = '150'
AND u.id = activitylog.userid)
ORDER BY TIMESTAMP DESC

Answer 2

You should rewrite the query using IN instead of OR like Pranesh Janarthanan's answer suggests, because OR is a performance killer.
In addition, you need indexes to avoid the expensive sequential scan on activitylog:
CREATE INDEX ON activitylog (timestamp);
CREATE INDEX ON activitylog (url);
Which of these indexes you need depends on how selective the respective conditions are.
Try with each of these indexes and with both (which may give you a “Bitmap And”) and keep what works best.

Answer 3

You should make sure you have the right indexes. Also, let's optimize the query:
SELECT id
FROM activitylog
WHERE url in ('/staff/save/117', '/staff/create/117')
AND timestamp > '1990-01-01 00:00:00'
AND
(
(userid = 150) or
EXISTS
(
select 1
from users workmate
join users u150
on workmate.companyid = u150.companyid and u150.id = 150
and activitylog.userid = workmate.id
)
)
ORDER BY timestamp DESC