If a client-side application is multi-threaded or multi-process, do all processes share a single client-side object cache or does each have its own object cache?
No. The application processes do not share the same client-side object cache. Each application process can have one or more client-side object caches. A client-side object cache is allocated for every OCI environment handle initialized in object mode. Multiple threads of a process can share the same client-side object cache by sharing the same OCI environment handle.