A method comprising: receiving , at a first database server , a first command to be executed against a first pluggable database of a first container database containing a plurality of pluggable databases from a database client ; wherein said first pluggable database is a proxy for a second pluggable database contained within a second container database , wherein the first container database contains data for forwarding queries to a second database server that hosts said second container database , wherein the second container database is different than the first container database and the second database server is different than the first database server ; wherein said first pluggable database contains first statistics about database objects in said second pluggable database and said second pluggable database contains second statistics about said database objects in said second pluggable database ; based on the first statistics , said first database server generating a query plan for executing said first command; wherein executing the query plan includes: based on the data for forwarding queries, the first database server forwarding a second command to the second database server for execution against the second pluggable database ; the first database server receiving results for the second command from the second database server ; based on the results for the second command, the first database server sending results for the first command to the database client . receiving , at a first database server , a first command to be executed against a first pluggable database of a first container database containing a plurality of pluggable databases from a database client ; wherein said first pluggable database is a proxy for a second pluggable database contained within a second container database , wherein the first container database contains data for forwarding queries to a second database server that hosts said second container database , wherein the second container database is different than the first container database and the second database server is different than the first database server ; wherein said first pluggable database contains first statistics about database objects in said second pluggable database and said second pluggable database contains second statistics about said database objects in said second pluggable database ; based on the first statistics , said first database server generating a query plan for executing said first command; wherein executing the query plan includes: based on the data for forwarding queries, the first database server forwarding a second command to the second database server for execution against the second pluggable database ; the first database server receiving results for the second command from the second database server ; based on the results for the second command, the first database server sending results for the first command to the database client . based on the data for forwarding queries, the first database server forwarding a second command to the second database server for execution against the second pluggable database ; the first database server receiving results for the second command from the second database server ; based on the results for the second command, the first database server sending results for the first command to the database client . <EOS>