#DateWhereItemComment
59508 Sep 2016 @ 01:26 PDTcarrie's blogNew opportunities for statistics collection in Teradata 14.0Hi Nazy,   If you don't collect stats for each separate combination, then there will no histogram where the optimizer can see the number of uniques and the interval values.  So if y...
59407 Sep 2016 @ 09:37 PDTcarrie's blogNew opportunities for statistics collection in Teradata 14.0Hi Nazy,   The 32 bytes I mentioned is not directly related to MAXVALUELENGTH.   MAXVALUELENGTH only applies to the number of characters that are stored in the histogram intervals ...
59307 Sep 2016 @ 08:25 PDTcarrie's blogEasing Into Using the New AutoStats FeatureChandra,   USECOUNT logging is not just used for skipping stats.  It is also used for statistics extrapolation.   You will not get skipping if USECOUNT logging is off, and the...
59201 Sep 2016 @ 04:00 PDTcarrie's blogEasing Into Using the New AutoStats FeatureResponse to the comment from 2 days ago:   Chandra,   The amount of time before skipping will be considered by the optimizer depends.  The optimizer usually looks for at least 5 ...
59101 Sep 2016 @ 03:55 PDTcarrie's blogHow Resources are Shared in the SLES 11 Priority SchedulerSamir,   Just to be sure that I understand what you mean when you say   " In workload distribution, i see that we have only tactical and timeshare defined"  Are you ...
59023 Aug 2016 @ 04:48 PDTcarrie's blogEasing Into Using the New AutoStats FeatureChandra,   Below are the responses I was able to get to your questions:   YOUR QUESTION:  Can you advise on archiving the TDSTATS database ,statsmanager user setup. I read the ma...
58922 Aug 2016 @ 08:13 PDTcarrie's blogEasing Into Using the New AutoStats FeatureChandra,   I have been trying to find someone in engineering who knows what the answer is.   When I am able to get a response, I will post it here.   Thank you for the re...
58808 Aug 2016 @ 08:54 PDTcarrie's blogDetermining Precedence Among TASM Planned EnvironmentsNazy,   Unfortunately, I can't tell you what settings would be best for you without being there on site and seeing all the workload management detail as a whole.     ...
58704 Aug 2016 @ 01:00 PDTcarrie's blogDetermining Precedence Among TASM Planned EnvironmentsHi Nazy,   It is not a recommended practice to move a workload to a different tier across planned environments.    I don't believe Viewpoint Workload Designer will even al...
58628 Jul 2016 @ 01:52 PDTcarrie's blogStatistics Collection Recommendations – Teradata 14.10, 15.0 and 15.10Chandrasekhar,   The NoDot0Backdown setting needs to be changed to TRUE. The logic used by Analyze Jobs to detect staleness relies on UDI counts from USECOUNT logging in conjunction with the...
58521 Jul 2016 @ 08:10 PDTcarrie's blogUsing the ResUsageSAWT table to Monitor AMP Worker TasksHi Helena,   If you are running out of AMP worker tasks (AWT) that can slow a query down.   Query steps require AWTs to execute, and if all the AMPs a query step is running in do n...
58427 Jun 2016 @ 04:41 PDTcarrie's blogNew opportunities for statistics collection in Teradata 14.0Hi Nazy,   I can't think of any reason there would be a value in collecting stats on rowID.   RowIDs are often used in single-table join indexes as a means for the database cod...
58324 Jun 2016 @ 09:04 PDTcarrie's blogHow Resources are Shared in the SLES 11 Priority SchedulerAmit,   You are correct in your basic understanding of how dynamic virtual partitions work.   I also agree with you that using the dynamic sharing of resources between virtual part...
58217 Jun 2016 @ 02:32 PDTcarrie's blogStatistics Collection Recommendations – Teradata 14.10, 15.0 and 15.10RESPONSE TO SECOND QUESTION:   If UDI counts are available, they will always be used instead of random AMP sampling.  So if you see that your histogram for that statistic carries UDI co...
58117 Jun 2016 @ 02:31 PDTcarrie's blogStatistics Collection Recommendations – Teradata 14.10, 15.0 and 15.10RESPONSE TO FIRST QUESTION:     Even if you have usecount logging on, the information is not able to be stored in the statistics  histogram, and therefore cannot be used for extrap...
58010 Jun 2016 @ 03:58 PDTcarrie's blogStatistics Collection Recommendations – Teradata 14.10, 15.0 and 15.10Katie,   The above posting constitutes overall recommendations on what statistics to collect.  You will have to evaluate which columns in your tables these recommendations apply to.&nbs...
57910 Jun 2016 @ 08:08 PDTcarrie's blogExpediting Express RequestsA change to the EnableExpReq does not require a restart.   You don't "throw a workload  at it" because the EnableExpReq setting is applied universally, it is not targeted ...
57803 Jun 2016 @ 08:20 PDTcarrie's blogReserving AMP Worker Tasks? Don’t let the Parameters Confuse You!Sachin,   You can consider applying the suggestions in my blog posting titled: " Expediting Express Requests".  You have to reserve at least two AWTs in the tactical reserves ...
57703 Jun 2016 @ 08:18 PDTcarrie's blogEasing Into Using the New AutoStats FeatureNaga,   The AutoStats APIs are implemented as stored procedures and are documented in the Application Programming Reference in the chapter entitled “Automated Statistics Management API...
57603 Jun 2016 @ 08:17 PDTcarrie's blogStatistics Threshold Functionality 101If you want the system to consider downgrade to sampling, you have to turn off the system threshold option.  As you say you have found out by trying it, if SysChangeTresholdOption is on, the o...
57527 May 2016 @ 01:44 PDTcarrie's blogHow Resources are Shared in the SLES 11 Priority SchedulerHi Naga,   A service level goal (SLG) is only for reporting purposes, so you can compare actual performance against your goals.  It is optional.  It sounds like you were under the ...
57427 May 2016 @ 01:42 PDTcarrie's blogReserving AMP Worker Tasks? Don’t let the Parameters Confuse You!Hi Sachin,   An express request is usually issued in order to get particular information from the data dictionary, such as to validate the columns in a table that the query uses, or to get a...
57327 May 2016 @ 08:09 PDTcarrie's blogAMP Worker Task Resource Limits & Increased Load Limits for MLOADXHi Samir,   First, only the TPT Update supports MLOADX. Standalone MultiLoad does not support MLOADX.   Second, in the default setting, the user just submits a TPT Update job and the ...
57223 May 2016 @ 03:04 PDTcarrie's blogHow Resources are Shared in the SLES 11 Priority SchedulerSetting a service level goal (SLG) is an option within workload management.   You are not required to set a service level goal for a workload, and it may not make much sense for most appl...
57123 May 2016 @ 09:19 PDTcarrie's blogEasing Into Using the New AutoStats FeatureYou are correct.  Autostats uses tableIds to join it’s infrastructure (tdstats repository)  with the dictionary.   Thanks, -Carrie 

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