在 AWS RDS 上删除没有超级用户权限的 postgresql 数据库

Question

I'm trying to delete a postgres database on an AWS RDS service with a bash script. Based on some answers here I came up with this:

#!/bin/bash -ex

DATABASE="confluence"
USER="postgres"
export PGPASSWORD="XXX"

PORT="5432"
HOST="postgres.XXX.eu-central-1.rds.amazonaws.com"

echo "drop db"
DROP_DB_COMMAND=$(cat <<EOF
REVOKE CONNECT ON DATABASE ${DATABASE} FROM public;
SELECT pg_terminate_backend(pg_stat_activity.pid)
FROM pg_stat_activity
WHERE pg_stat_activity.datname = '${DATABASE}';
DROP DATABASE ${DATABASE}
EOF
)

psql \
  --command "${DROP_DB_COMMAND}" \
  --host=${HOST} \
  --port=${PORT} \
  --user=${USER}

However I get an error DROP DATABASE cannot run inside a transaction block .

I understand that I have to terminate all existing connections and not be connected to the database I want to delete. What are the proper psql commands to achieve this?

As this is AWS RDS, the superuser rdsadmin is owned by AWS, so I can't use any solution that needs superuser rights.

Answer 1

Turns out that as opposed to MySQL you can't do it in one transaction. This works:

#!/bin/bash -ex

DATABASE="confluence"
USER="postgres"
export PGPASSWORD="XXX"

PORT="5432"
HOST="postgres.XXX.eu-central-1.rds.amazonaws.com"

echo "terminate connections to db"
TERMINATE_COMMAND=$(cat <<EOF
REVOKE CONNECT ON DATABASE ${DATABASE} FROM public;
SELECT pg_terminate_backend(pg_stat_activity.pid)
FROM pg_stat_activity
WHERE pg_stat_activity.datname = '${DATABASE}';
EOF
)


psql \
  --command "${TERMINATE_COMMAND}" \
  --host=${HOST} \
  --port=${PORT} \
  --user=${USER}


echo "drop db"
DROP_DB_COMMAND=$(cat <<EOF
DROP DATABASE ${DATABASE};
EOF
)

psql \
  --command "${DROP_DB_COMMAND}" \
  --host=${HOST} \
  --port=${PORT} \
  --user=${USER}