Report Developer Control Of Applying Hints to Analytics Queries

Question

There are numerous ways to apply hints to the queries generated by Analytics:
- Table level
- Join level
- Evaluate calculation
Each has its advantages and drawbacks.
- Table level: applies the hint to every query that references the table.
- Join level: applies the hint whenever the join is used in the query.
- Evaluate: allows the report developer to include a hint, but can't control where Analytics decides to apply the hint.
I propose another method for the report developer to apply hints, when needed, that uses join level hints. All the report developer
does is add the hint column to the Answer or add a filter based on the hint column to the Answer to apply the hint.
Setup
NOTE: I suggest you do consistency checks along the way, especially before starting work in the next Layer, to be sure that all setup errors are resolved early.
1) Start by defining a Logical SQL table in the Physical Layer using the following SQL: Select 1 Hint from dual
2) Alias this table for each hint to be defined for report developer usage. As an example, alias the hint table, creating
No Star and Parallel alias tables.
3) Join each alias to the physical layer fact tables, using a complex join, where the hint could be applied. In the Join definition screen, put the hint in the HINT field and enter 1=1 for
in the Expression section. Yes, we are creating a cartesian join between the hint and the other joining table. As the hint table always returns one and only one row, there
is no effect on the rows returned by the query. For No Star, you
put NO_STAR_TRANSFORMATION in the Hint field. For Parallel, you put PARALLEL(<physical table name>, default, default), where the physical table name
is the name of the actual database table, not the name of the alias table (Analytics will put the alias in the place of the database table name
when it generates the SQL). Additionally, for hints that have no parameters, you only need to join it
to the Fact tables in a query and not necessarily the dimensions. If you include fields from multiple fact tables, the hint will be applied
for each fact table. So, you may see the hint multiple times in the SQL (something like SELECT /*+ NO_STAR_TRANSFORMATION NO_STAR_TRANSFORMATION */ t00001.col1...)
4) Add the hint alias tables to the BMM Layer.
5) Rename the Hint field in each of the BMM hint tables to identify the hint being applied. For No Star, change the column name from Hint to No Star Hint. For Parallel,
change the column name from Hint to Parallel Hint.
6) Set the hint column as a key.
7) Join the BMM hint tables to the appropriate fact tables, using a complex join.
8) Define each hint table as a dimension.
9) Set the Logical Level in the Content tab in each of the sources of the joined tables to use the Detail of the hint dimension.
10) Create a folder in the Presentation Layer called Hints
11) Place each BMM hint field into the Presentation Layer Hints folder.
To apply a hint to your Answer, either add the Hint field to your Answer or create a filter where the Hint field is equal to/is in 1 (the number one). Check that the SQL generated
contains the hint, in Answers, go into Administration, Session Manager, and view the log for the user (the user log level will need to have been set to 7 to see the SQL generated).
Use of hints in more complex setups can be done by performing a setup of the hints that is parallel to the fact table setup. As an example, if you specify fragmentation content and a where
clause in your BMM for your fact tables, you would setup parallel physical layer hint tables and joins, BMM objects and joins, fragmentation content, and where clauses based on the
hint tables (only hint tables are referenced in the where clause).
As any database person knows, hints can either help or degrade the performance of queries. So, taking the SQL of the pre-hint Answer and figuring out which hints give the best
performance is suggested, prior to adding the hint fields/filters to the Answer.

Answer 1

Hi Oliver,
I would suggest you to have a look at the below WLST script which would give you the required report of the active threads and it would be send an email too.
Topic: Sending Email Alert for Threads Pool Health Using WLST
http://middlewaremagic.com/weblogic/?p=5433
Topic: Sending Email Alert for Hogger Threads Count Using WLST
http://middlewaremagic.com/weblogic/?p=5423
Also you can use the below script in case of the stuck threads, this script would send you an email with the thread dumps during the issue occurred.
Topic: Sending Email Alert For Stuck Threads With Thread Dumps
http://middlewaremagic.com/weblogic/?p=5582
Regards,
Ravish Mody