Extensibility features in PQSQL

[Danushka Menikkumbura <danushka.menikkumbura@xxxxxxxxx>]

Hi all,

I am interesting in understanding the extensibility features available in PostgreSQL. For instance what it takes to define a new operator or a new index and in particular what goes into the query optimizer in that case.

Please kindly point me to some useful resources on this.

Thanks and Regards,

Danushka