background_dump_dest = c:\oracle\admin\COIN\bdumpEvery database has an alert log file, to which it logs messages about significant events such as startup, shutdown, log switches, and so forth. Any serious errors are also logged to this file. The background_dump_dest parameter controls the location of the alert log file.
user_dump_dest = c:\oracle\admin\COIN\udumpThe user_dump_dest parameter controls the directory used for trace files created by database users for debugging purposes.
db_files = 20The db_files parameter controls the amount of memory that Oracle allocates for managing database files.
compatible = 8.1.5The compatable parameter allows you to have Oracle mimick the behavior of a previous release of the software.
processes =30The process parameter controls the number of server processes that can connect to the instance. This effectively limits the number of database users. This value includes lock processes (LCKn) and job queue processes (SNPn). So if your instance has one lock process, and one job queue process, that leaves room for 28 user processes.
optimizer_mode =chooseThis is a setting that Oracle recommends for all new development. It enables the use of the cost-based optimizer, as opposed to the rule-based optimizer. The cost-based optimizer makes decisions about how to execute a query based on its estimate of the actual work that needs to be done. All of Oracle's development efforts are going into enhancing the cost-based optimizer.