We are evaluating adding TimesTen to an existing application which is currently using oracle, planning to cache a few tables in TimesTen (AWT Global Cache group) for the purpose of increased performance in a process A. The tables we are considering for caching are used intensively (insert/update/read) by Process A.
There are other tables used by process A that may not be appropriate for caching in TT. As I see it there are 2 options for access to these other tables:
1) Have Process A connect directly to TimesTen and access all non-cached tables via PassThrough. Process A will read as well as insert and update in these other tables in Oracle.
2) Have Process A connect to TimesTen for access to Cached tables in TT and also connect to Oracle for access to the other tables owned/managed by the oracle instance. This would require client/server connection as well as adding TimesTen Driver Manager (TTDM) library.
It seems that either method has a drawback: The “TimesTen Database Best practices” indicates that a separate Oracle DB connection is preferable to using passThrough.
This speaks for using option 2, thereby avoiding use of PassThrough. However in TimesTen Driver manager User guide states “The performance of client/server access is significantly less than that of direct mode access.”, so it seems that with option 2 Process A interaction with the cached tables will be slower as compared to using direct connection in option 1.
We have to carefully weigh the effort of changes to the application logic required by option 2. Providing additional logic required for managing connection to TT as well as to Oracle in one application may not be trivial. At the same time we are considering TT is for the purpose of performance and we would want to choose a strategy that is the better option from a performance point of view.
Advise?
M