SHARED SERVER ARCHITECTURE
- Multiple user requests will be received by dispatcher which will be placed in request queue.
- Shared server processes will take information from request queue and will be processed inside the database.
- The results will be placed in response queue from where dispatcher will send them to corresponding users.
- Instead of PGA, statements will get executed in UGA (user global area) in shared server architecture.
- Shared server architecture can be enabled by specifying following parameters.
- CIRCUITS and MAX_CIRCUITS (optional)
- This architecture should be enabled only if ora-04030 or ora-04031 errors are observed frequently in alert log file.
- To make shared server architecture effective, SERVER=SHARED should be mentioned in client TNSNAMES.ORA file.
- A single dispatcher can handle 20 user requests where as a single shared server process can handle 16 requests concurrently.
Note: SMONn can have 16 slave processes and DBWRn can have 20 slave processes working concurrently
Note: startup and shutdown is not possible if sysdba connects through shared server connection