Simplifying AMP Worker Task Monitoring and Getting it Right - comment by...
Thank you for this info. I learned something today. Regards, Suhail
View ArticleRequest Cache Hits & Misses - comment by suhailmemon84
ok. Thanks for the direction. I was thinking along the same lines too. The only way you can bound an application to a specific PE/set of PE's is by ensuring that the application connects to the same...
View ArticleStatistics collection recommendations – Teradata 14.0 - comment by ppg
Hi Carrie, What is the thumb of rule you would recommend for tables larger than 1TB. I totally understand that it depends on how the data is changes in the table. I was leaning more towards 10% size...
View ArticleAre AMP Worker Tasks used by FastExport in Response Mode? - comment by...
Thank you Carrie. Sorry for the delayed response (was on vacation). Just want to ask one more question on the same topic. We recently allocated 1 AWT via Reserved AWT for the tactical workload, and we...
View ArticleStatistics collection recommendations – Teradata 14.0 - comment by Ekladios
Thanks Carrie for the clarification. Regarding the second question we have seen that when sample stats was collected the join took very long time, product join plan, and we had to abort it. Then...
View ArticleStatistics collection recommendations – Teradata 14.0 - comment by carrie
ppg- The same recommendations for recollection of statistics apply no matter what the table size. 10% change is just a rough guess, but it is all that we have to recommend at this time. Future...
View ArticleAre AMP Worker Tasks used by FastExport in Response Mode? - comment by carrie
The AWT Limit setting is by default 50 in Workload Designer. The AWT limit value does not indicate how many AWTs are in the reserved AWT pool. That is determined by the Reserved AWT setting. So it...
View ArticleAre AMP Worker Tasks used by FastExport in Response Mode? - comment by...
Thanks for clarifying this. I have one more question on the same note, we have been seeing sessions with high PJI and UIO (Unnecessary IO) and Skew. But sometimes one Skew & UIO for that session...
View ArticleAre AMP Worker Tasks used by FastExport in Response Mode? - comment by carrie
Geeta, The product join indicator uses this formula: (AMPCPUTime * 1000)/TotalIOCount Usually if it is 3 or higher it may indicate something that needs further investigation, but it could certainly...
View ArticleAre AMP Worker Tasks used by FastExport in Response Mode? - comment by...
Got it. Thank you Carrie.
View ArticleReserving AMP Worker Tasks? Don’t let the Parameters Confuse You! - comment...
Hi Carrie, If we want to intelligently set the AWT Limit(rather than blindly set the value of 50), then should we be doing the following analysis? 1.Check history resusage data and probe values of...
View ArticleIntrepreting DBQL DelayTime in Teradata 13.10 - comment by Smarak0604
Hello Carrie, My Question is: If a Query is in Delay Queue, then it means it is waiting for the say, Queries Count be lower than the Defined Throttle Limit. The DBA can Release such Delayed Query by...
View ArticleReserving AMP Worker Tasks? Don’t let the Parameters Confuse You! - comment...
Suhail, WorkEight is the number of expedited new work requests (similar to WorkNew). WorkNine is the number of expedited spawned requess (similar to WorkOne). AWT Limit is the setting in Workload...
View ArticleIntrepreting DBQL DelayTime in Teradata 13.10 - comment by carrie
When a query is manually released from the delay queue, or if a query is demoted into a workload that has a throttle whose limit has already been reached, the query count for that throttle will...
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TASM State Changes are Streamlined in Teradata 14.0 - blog entry by carrie
A state matrix is a construct that allows you to intersect your business processing windows with the health conditions of your system. Why should you care about this abstraction? The state matrix in...
View ArticleNew opportunities for statistics collection in Teradata 14.0 - comment by Ian...
Hi Carrie In the SQL Data Definition Langauge - Detailed Topics manual for TD14 it lists: - SYSTEM MAXINTERVALS - SYSTEM MAXVALUESLENGTH With SYSTEM SAMPLE the manual suggests that Teradata Database...
View ArticleNew opportunities for statistics collection in Teradata 14.0 - comment by carrie
Hi Ian, That auto adjustment to the sampling percent is not done in 14.0. This is implemented in 14.10. Somehow, this statement made it into the document prematurely, and I have put in a request for...
View ArticleHow to Calculate Your Max Number of Usable AMP Worker Tasks - comment by usmans
Hello Carrie, Thanks for the read. I got to this after doing a WBT of yours on AWTs. (made the reading all the more easier). I have a question. The project I am currently working on consistently uses...
View ArticleRecommended Dictionary Statistics to Collect in Teradata 14.0 - blog entry by...
Collecting statistics on data dictionary tables is an excellent way to tune long-running queries that access multi-table dictionary views. Third party tools often access the data dictionary several...
View ArticleStatistics collection recommendations – Teradata 14.0 - comment by Paul Johnson
@MadMac - totally agree. Far too much CPU can be wasted on a poor stats collection regime, often unknowingly. I wrote this last year to blow off...
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