TASM Exception applies ... or NOT


TASM Exception applies ... or NOT


Our TASM active ruleset contains exceptions - I/O exceptions limited to 1 in the case - applying to queries when classification criteria are met (Teradata 15.00.04, Viewpoint 15.11.00)

In that context a query with SAMPLE bypassed the exception test and returned an answerset, although an error 3156 and Abort action is logged in dbqlogtbl and TdwmExceptionlog !

ErrorText column in dbqlogtbl is empty, ErrorText column in TdwmException is filled with "I/O:95159." 

So Exception and Abort action are logged and the query returns rows: is that odd behaviour due to SAMPLE option ?

Other queries (same classification criteria) without sample are aborted as well ...





Teradata Employee

Re: TASM Exception applies ... or NOT

Was this a singular occurrence or something repeatable?


There is a small timing window between when TASM decides to trigger an exception and when the asynchronous abort request is actually processed.


Re: TASM Exception applies ... or NOT

Hi Fred,

it is repeatable.

I sent three queries (same user, profile and other classification criteria) from STUDIO:

1- select * from table sample 100;   -- OK with errorcode 3156 (dbqlogtbl) and 100 rows in answerset 

2- select * from table where UPI_column in ( 10 values);  -- KO with errorcode 3156 (dbqlogtbl)

errortext (dbqlogtbl): "Request aborted by TDWM. Exception criteria exceeded:   I/O Count."

3- select * from table sample 100;   -- OK with errorcode 3156 (dbqlogtbl)  and 100 rows in answerset. 


PS: Exception is defined on I/O count limited to 1


Notice that a switch between SessionWDID and WDID is done according to criteria analysis.

Exception is associated to the workload in use when executing the query (WDID).