Tuesday, July 1, 2014

OBIEE 11g : Query Logging

OBIEE 11g : Query Logging


OBIEE 11g allows controlling the information that is being logged.
We can fetch the logical as well as physical query by enabling log level.
You can enable logging level for individual users, system user, and individual request.

OBIEE provides different levels of logging as from 0(no logging) to 5(all the information).


Query Logging Levels Description:

Logging Level
Information That Is Logged
Level 0
No logging.
Level 1
Logs the SQL statement issued from the client application. Also logs the following:
·         Physical Query Response Time — The time for a query to be processed in the back-end database.
·         Number of physical queries — The number of queries that are processed by the back-end database.
·         Cumulative time — The sum of time for all physical queries for a request (that is, the sum of all back-end database processing times and DB-connect times).
·         DB-Connect time — The time taken to connect to the back-end database.
·         Query cache processing — The time taken to process the logical query from the cache.
·         Elapsed time — The time that has elapsed from when the logical query is presented to the BI Server until the result is returned to the user. Elapsed time can never be less than response time, because elapsed time takes into account the small extra time between the logical query being presented to the BI Server to the start of preparation of the query. In cases where this delta time is negligible, the elapsed time equals the response time.
·         Response time — The time taken for the logical query to prepare, execute, and fetch the last record. This matches the TOTAL_TIME_SEC that is logged in usage tracking.
·         Compilation time — The time taken to compile the logical query.
·         For each query, logs the query status (success, failure, termination, or timeout), and the user ID, session ID, and request ID.
Level 2
Logs everything logged in Level 1.
Additionally, for each query, logs the repository name, business model name, subject area name, SQL statement issued against the physical database, queries issued against the cache, number of rows returned from each query against a physical database and from queries issued against the cache, and the number of rows returned to the client application.
Level 3
Logs everything logged in Level 2.
Additionally, adds a log entry for the logical query plan, when a query that was supposed to seed the cache was not inserted into the cache, when existing cache entries are purged to make room for the current query, and when the attempt to update the exact match hit detector fails.
Do not select this level without the assistance of Oracle Support Services.
Level 4
Logs everything logged in Level 3.
Additionally, logs the query execution plan. Do not select this level without the assistance of Oracle Support Services.
Level 5
Logs everything logged in Level 4.
Additionally, logs intermediate row counts at various points in the execution plan. Do not select this level without the assistance of Oracle Support Services.
Level 6 and 7
Not used.



Viewing logs:

Logs get stored in NQSQUERY.log file.
It is located at,

<instance_home>/diagnostics/logs/OracleBIServerComponent/coreapplication_obis1/

Also logs can be viewed from dashboard administration.
We can fetch logs from Administration>Manage Sessions

Here we can see all the logs generated for different users.


Please check my next post on how to set query log level,

OBIEE 11g : How to set log level?



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