diff --git a/.gitignore b/.gitignore
index 8ae1d06..fe2cd71 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,3 +4,5 @@ dist-newstyle
 *.swp
 result
 bench.html
+download
+pgdata
diff --git a/with-db.sh b/with-db.sh
index f10d509..09bb70d 100755
--- a/with-db.sh
+++ b/with-db.sh
@@ -1,14 +1,21 @@
-BASE_DIR=$(mktemp -d)
+if [ -z "$BASE_DIR" ]; then
+    BASE_DIR=$(mktemp -d)
+fi
 export PGDATA="$BASE_DIR/pgdata"
 
 # On error or exit: Stop the DB server
 stop_db_server() {
-    pg_ctl stop --wait
+    pg_ctl stop -o "-p 5433" --wait
 }
 trap stop_db_server EXIT
 
-initdb --username=yore-test --auth=trust
-pg_ctl start --wait
-createdb yore-test --username=yore-test
+if [ ! -s "$PGDATA/PG_VERSION" ]; then
+    initdb --username=yore-test --auth=trust || true
+    DO_CREATE_DB=1
+fi
+pg_ctl start -o "-p 5433" --wait
+if [ -n "$DO_CREATE_DB" ]; then
+    createdb -p 5433 yore-test --username=yore-test || true
+fi
 
 "$@"