Help in dealing with OOM

Hello Experts!

My secondary instance has been unstable today. The service is crashing with
Out of Memory. Please see below error
(/var/log/postgresql/postgresql-2024-10-14.log):

10.2.52.50,2024-10-14 15:28:11 IST,686671,finance_revamp,finance_b2b,1,LOG:
duration: 1148.527 ms statement: SELECT "tripschedule"."id",
"tripschedule"."name", "tripschedule"."branch_id",
"tripschedule"."route_id", "tripschedule"."route_name",
"tripschedule"."bus_id", "tripschedule"."path",
"tripschedule"."path_timings", "tripschedule"."recurring_days",
"tripschedule"."start_time", "tripschedule"."end_time",
"tripschedule"."start_date", "tripschedule"."end_date",
"tripschedule"."created_at", "tripschedule"."created_by",
"tripschedule"."shift", "tripschedule"."is_deleted",
"tripschedule"."is_active", "tripschedule"."is_cancelled",
"tripschedule"."branch_latitude", "tripschedule"."branch_longitude",
"tripschedule"."polygon_id", "tripschedule"."is_after_noon_shift" FROM
"tripschedule" INNER JOIN "bus" ON ("tripschedule"."bus_id" = "bus"."id")
WHERE ("bus"."vehicle_no" = 'KA51AH1922' AND "tripschedule"."end_date" >=
'2024-10-14'::date AND "tripschedule"."is_active" AND
"tripschedule"."recurring_days" && ARRAY[1]::integer[] AND
"tripschedule"."start_date" <= '2024-10-14'::date AND
("tripschedule"."start_time" BETWEEN '14:57:57.654167'::time AND
'15:57:57.654167'::time OR "tripschedule"."end_time" BETWEEN
'14:57:57.654167'::time AND '15:57:57.654167'::time OR
("tripschedule"."start_time" <= '15:27:57.654167'::time AND
"tripschedule"."end_time" >= '15:27:57.654167'::time))) ORDER BY
"tripschedule"."id" DESC LIMIT 1
10.2.52.22,2024-10-14 15:28:11
IST,686748,orchids_letseduvate_db,autoscaling,1,LOG: duration: 468.028 ms
statement: SELECT (1) AS "a" FROM "test" INNER JOIN "test_section_mapping"
ON ("test"."id" = "test_section_mapping"."test_id") INNER JOIN
"test_subjects" ON ("test"."id" = "test_subjects"."test_id") INNER JOIN
"user_response" ON ("test"."id" = "user_response"."test_id") WHERE
(("test"."test_date")::date >= '2024-10-14'::date AND
("test"."test_date")::date <= '2024-10-17'::date AND NOT "test"."is_delete"
AND "test_section_mapping"."sectionmapping_id" IN (136364) AND
"test_subjects"."subject_id" = 16 AND NOT "user_response"."is_delete" AND
"user_response"."submitted_by_id" = 61725) LIMIT 1
,2024-10-14 15:28:11 IST,2334064,,,8,LOG: checkpointer process (PID
2334587) was terminated by signal 9: Killed
,2024-10-14 15:28:11 IST,2334064,,,9,LOG: terminating any other active
server processes
10.2.52.50,2024-10-14 15:28:11
IST,686752,mcollege_letseduvate_db,finance_b2b,1,WARNING: terminating
connection because

This is from the OS log (/var/log/kern.log):

oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=/,mems_allowed=0,global_oom,task_memcg=/system.sli
ce/system-postgresql.slice/postgresql(at)12-main(dot)service
,task=postgres,pid=2334587,uid=114
494 Oct 14 09:58:10 gce-k12-prod-as1-erp-pg-secondary kernel:
[6905020.514569] Out of memory: Killed process 2334587 (postgres)
total-vm:26349584kB, anon-rss:3464kB, file-rss:0kB, shmem-rs
s:21813032kB, UID:114 pgtables:49024kB oom_score_adj:0

Regards
Siraj