postgresql 9.0 streaming replication + hot standby is running. Now i need to add one more database to current cluster. What is the best way of doing this? I have a backup file about 20GB. should i restore to that cluster? can standby server have all the data?
Yes, you can restore the backupfile to your hot-standby. But there are some detail you should notice. The following are steps I suggest
those steps will have an impact on performace, so take care.
Hz.Root, your question has many open ends but I will try to answer.
Just create a new database in master server and populate it.
Yes. To be precise, you restore it to the database, not to the cluster.
Standby server MUST have all the data - that is it's purpose. Every database, and every other object that is in primary PostgreSQL cluster, will be replicated to secondary server.