FreeLists / oracle-l / Re: What is RPI calls (user calls from statspack)

[Nigel Thomas <nigel_cl_thomas@xxxxxxxxx>]

Barbara wrote:
> I found a couple of references to the statistic "User Calls" in 
> statspack reports as follows:
> "Oracle allocates resources to keep track of relevant user call data 
> structures every time you log in, parse, or execute.  When determining 
> activity, the ratio of user calls to RPI calls indicates how much 
> internal work gets generated as a result of the type of requests the 
> user is sending to Oracle."

In the good ol' days, knowing the proportion of recursive calls was useful; 
your app called (non-recursive) SQL, and under the counters Oracle called 
recursive SQL to do things like parsing, space management, etc. One way of 
tuning an app was to try to minimise those calls (eg: by parsing just once; by 
pre-allocating extents, by coalescing free space, etc).

However, when PL/SQL was invented (not so recently!), you got to be able to 
make your own recursive calls; any call to SQL from an anonymous block is 
"recursive". And you can easily generate many levels of recursion. So knowing 
the proportion of recursive calls per se is not so helpful (aka useless - quite 
right Steve). Now you need to be able to sort the (user) wheat - real stuff you 
want to do - from the (system) chaff - what Oracle does behind the scenes - at 
the same time as making sure you realise what lower level stats are being 
rolled up into the higher levels of your tkprof output.

Regards Nigel