As you can read in the previous comment, implementing application logic in stored procedures is not good idea. The better place is application server, whatever it means.

Please, try to estimate some statistical conditions (load of the RDBMS, quantity of accesses per second, ...) and, after that, find the simplest solution which will satisfy it. There is not too many sites, which needs to deal 10 complex operations per each second... Hopefully sql with bind variables will be OK, specially, when you enhance it by optimization hints.

I did not played Oracle for few years, but I remember that speed depends on too many factors. Configuration, load, quantity (and statistical distribution !) of rows in affected tables, indices, ... Nobody is able to create optimal application from the scratch.