diff --git a/group_vars/all/17_resource.yml b/group_vars/all/17_resource.yml
index 281b5eff75..4392f54ade 100644
--- a/group_vars/all/17_resource.yml
+++ b/group_vars/all/17_resource.yml
@@ -43,16 +43,9 @@ RESOURCE_MEM_LIMIT: "{{ RESOURCE_MEM_LIMIT_NUM }}g"
 RESOURCE_PIDS_LIMIT: 512
 
 POSTGRES_VCPUS: "{{ ansible_facts['processor_vcpus'] | int }}"
-POSTGRES_TOTAL_RAM_MB: "{{ ansible_facts['memtotal_mb'] | int }}"
 POSTGRES_MAX_CONNECTIONS: "{{ [ ((POSTGRES_VCPUS | int) * 30 + 50), 400 ] | min }}"
 POSTGRES_ALLOWED_AVG_CONNECTIONS: "{{ (POSTGRES_MAX_CONNECTIONS | split_postgres_connections(lookup('path_absolute', 'roles'))) | int }}"
 POSTGRES_SUPERUSER_RESERVED_CONNECTIONS: 3
-POSTGRES_SHARED_BUFFERS_MB: "{{ ((POSTGRES_TOTAL_RAM_MB | int) * 25) // 100 }}"
-POSTGRES_SHARED_BUFFERS: "{{ POSTGRES_SHARED_BUFFERS_MB ~ 'MB' }}"
-POSTGRES_WORK_MEM_MB: "{{ [ ( (POSTGRES_TOTAL_RAM_MB | int) // ( [ (POSTGRES_MAX_CONNECTIONS | int), 1 ] | max ) // 2 ), 1 ] | max }}"
-POSTGRES_WORK_MEM: "{{ POSTGRES_WORK_MEM_MB ~ 'MB' }}"
-POSTGRES_MAINTENANCE_WORK_MEM_MB: "{{ [ (((POSTGRES_TOTAL_RAM_MB | int) * 5) // 100), 64 ] | max }}"
-POSTGRES_MAINTENANCE_WORK_MEM: "{{ POSTGRES_MAINTENANCE_WORK_MEM_MB ~ 'MB' }}"
 POSTGRES_MAX_LOCKS_PER_TRANSACTION: 256
 POSTGRES_DELAY: 2
 
diff --git a/roles/svc-db-postgres/vars/main.yml b/roles/svc-db-postgres/vars/main.yml
index ab4253a155..b1ff5e62c5 100644
--- a/roles/svc-db-postgres/vars/main.yml
+++ b/roles/svc-db-postgres/vars/main.yml
@@ -15,3 +15,6 @@ POSTGRES_EXPOSE_LOCAL: true
 POSTGRES_LOCAL_HOST: "127.0.0.1"
 POSTGRES_LIBRARIES: "{{ lookup('postgres_libraries', lookup('service_extensions', 'postgres').values() | sum(start=[]) | unique | list) }}"
 POSTGRES_RETRIES: 5
+POSTGRES_SHARED_BUFFERS: "{{ lookup('service_memory_mb', application_id, entity_name, 0.25) }}MB"
+POSTGRES_WORK_MEM: "{{ [ (lookup('service_memory_mb', application_id, entity_name, 0.5) | int) // ([ POSTGRES_MAX_CONNECTIONS | int, 1 ] | max), 1 ] | max }}MB"
+POSTGRES_MAINTENANCE_WORK_MEM: "{{ [ lookup('service_memory_mb', application_id, entity_name, 0.05) | int, 64 ] | max }}MB"
diff --git a/roles/web-app-discourse/templates/config.yml.j2 b/roles/web-app-discourse/templates/config.yml.j2
index 884d949e89..c72c6c1adc 100644
--- a/roles/web-app-discourse/templates/config.yml.j2
+++ b/roles/web-app-discourse/templates/config.yml.j2
@@ -22,7 +22,7 @@ params:
 
   ## Set db_shared_buffers to a max of 25% of the total memory.
   ## will be set automatically by bootstrap based on detected RAM, or you can override
-  db_shared_buffers: "4096MB"
+  db_shared_buffers: "{{ lookup('service_memory_mb', application_id, 'discourse', 0.25) }}MB"
 
   ## can improve sorting performance, but adds memory usage per-connection
   #db_work_mem: "40MB"