diff --git a/docker-compose.yml b/docker-compose.yml
index 0487c93..abcb184 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -112,7 +112,7 @@ services:
     # and the store-message-db-url is set to use Postgres
     image: postgres:15.4-alpine3.18
     restart: on-failure:5
-    shm_size: '1g'  # Set shared memory size to 1 GB
+    shm_size: "${POSTGRES_SHM:-1g}"  # Set default shared memory size to 1 GB
     environment:
       <<: *pg_env
     volumes:
diff --git a/set_storage_retention.sh b/set_storage_retention.sh
index 1b81f2e..986397d 100755
--- a/set_storage_retention.sh
+++ b/set_storage_retention.sh
@@ -54,10 +54,24 @@ fi
 # check if STORAGE_SIZE is already specified
 if [ -f "./.env" ]; then
     . ./.env
-    if [ -n "$STORAGE_SIZE" ]; then
-        >&2 echo "STORAGE_SIZE is specified in .env file, doing nothing"
-        exit 0
+fi
+
+# Set PostgreSQL container Shared Memory value
+if [ -z "${POSTGRES_SHM}" ]; then
+    TOTAL_MEM_MB=$(free -m|grep Mem| awk '{ print $2 }')
+    if [ "${TOTAL_MEM_MB}" -ge 4096 ]; then
+      # Allocate 2GB of Shared Memory for Postgres if machine has more than 4GB RAM
+      POSTGRES_SHM='2g'
+      echo "Setting PostgreSQL container SHM to ${POSTGRES_SHM}"
+      echo "POSTGRES_SHM=${POSTGRES_SHM}" >> .env
     fi
+else
+  >&2 echo "POSTGRES_SHM is already specified in .env file"
+fi
+
+if [ -n "$STORAGE_SIZE" ]; then
+    >&2 echo "STORAGE_SIZE is specified in .env file, doing nothing"
+    exit 0
 fi
 
 SUDO=""