Re: PostgreSQL 10.0 SELECT LIMIT performance problem

We have some serious performance problem with SELECTS when add limit, for example, execute time without limit ~250msec (316 rows returned), when add limit 20, execute time 15 – 50secs.

We have select with subselect filter:

select a.id, a.jdata

from oss_alarms a

where

                a.jdata->>'dn' in

                (

                    select o.jdata->>'ossDn'   

                    from oss_objects o, tvc_entity e

                    where e.jtype='object'   

                                                and o.jdata->>'sid'=e.jdata->>'siteId'      

                                                and tvc_unaccent(e.jdata->>'name') like tvc_unaccent('%zaube%')

                )

order by (tvc_convert_array_to_date(a.jdata -> 'alarmTime')) desc

limit 20;