Real Application Testing (RAT); questions

Question

Hi,
We are currently working on a missing involving RAT, both SPA and DB Replay.
The customer raised some questions and I was wondering if anybody has more detailed information to share?
FYI: we are using in most cases the API calls, as we don’t have an EMGC 11G available, only Database control.
h4. Q1: If the DB capture runs out of space, what would be the impact on Prod database
My response would be: no impact on the database as the recorder stops
Best Practice: create a separate location to store the recording
h4. Q2: What could be missing with RAT (SPA/DB Replay) --> gap analysis.
Reduce as most as possible the time needed by ADM (Development Team) in order to validate database migration.
The database team wants to be as independent as possible of the development team in order to do the upgrade of the databases more autonomous. They want to have an idea on what they could be missing if they use SPA and DB Replay to make sure they don't miss anything which could have an impact on the developers after the upgrade. Are there any particular things that SPA and DB-replay would miss, and as a consequence aren't tested, which could lead to unhappy developers after the upgrade of the database.
h4. Q3: Difference between DB Replay and SPA (when to use which one)
h4. Q4: Oracle recommends shutting down database before recording workload, but may not be always possible (Web Banking), when and how to do it then?
My response was to start recording at a the lowest load time.
Any other ideas to minimize the impact of a running instance
h4. Q5: Does it need to filter out sys/system, rman,... Activities during captures?
h4. Q6: The capture report is showing 5 user calls captured with Errors, but I can’t find any related information on what went wrong.
To what is this related?
Captured Workload Statistics
•     'Value' represents the corresponding statistic aggregated across the entire captured database workload.
•     '% Total' is the percentage of 'Value' over the corresponding system-wide aggregated total.
Statistic Name     Value     % Total
DB time (secs)     7.77     10.43
Average Active Sessions     0.03     
User calls captured     1713     9.09
User calls captured with Errors+_     5     
Session logins     23     32.39
Transactions     33     3.74
h4. Q7: During the capture we can execute an export AWR, but we also need to do an import AWR somewhere, and this is not documented on how this is done in the RAT User Guide.
Can you comment on how this process is working in order to do some proper reporting.

Answer 1

Q1
I have not had a space issue in the RAT capture files that caused a database issue when space ran out.
Q2
You will miss anything you filtered the capture on, anything that errored during the capture
Capture will also not get and to be aware of
Direct Path Load (SQL Loader)
Shared server (Oracle MTS)
Oracle Streams & Advanced Replication Streams
Non-PL/SQL based Advanced Queuing (AQ)
Flashback queries
OCI-based Object Navigation
Non SQL-Based Object Access
Distributed transactions, remote describe/commit operations (will be replayed as local transactions)
Q3
I typically use DB Replay for an overall work load perspective, SPA for SQL Level.
For example I will to a DB replay find from my reports SQL that needs a further look see and use SPA from there.
or potentially use SPA to focus on the SQL itself and not concern myself the the whole workload until I am ready.
Q4
Set the SCN for when capture is started, have the replay database be recovered to that SCN prior to any replay operation. No real need to shutdown, done this many times with success.
Q5
Typically I will filer any grid control agent or other agent software activities from the capture for sure.
Q6
Your Capture Report does not show anything?
Q7
You can extract and load AWR with the following packed procedures
sys.dbms_swrf_internal.awr_extract
sys.dbms_swrf_internal.awr_load