#DateWhereItemComment
39516 Jul 2014 @ 07:44 PDTcarrie's blogHow Resources are Shared in the SLES 11 Priority SchedulerVirtual partition hard limits and workload level hard limits in SLES11 will be available at the same time a WM COD is available.  All three levels of hard limits are bundled into a single feat...
39416 Jul 2014 @ 07:40 PDTcarrie's blogTips on using Sampled StatsSantanu,   If you are asking if using can use sampling when you collect statitics on an expression (whether aggregate or not), the anwer is yes, sampling for stats on expressions is supporta...
39311 Jul 2014 @ 01:44 PDTcarrie's blogChanges to the TASM AMP Worker Task Event in Teradata 13.10Lakshimi,   You are correct that parallel steps can result in more than 1 or 2 AMP worker tasks being used by a single request, particularly if it is multistatement request.   ...
39226 Jun 2014 @ 08:13 PDTcarrie's blogReserving AMP Worker Tasks? Don’t let the Parameters Confuse You!For TASM in Teradata 12 it is not enough to set the enforcement priority to tactical.  You must explictly expedite the allocation group.  This is done in the GUI screen that shows all the...
39124 Jun 2014 @ 08:28 PDTcarrie's blogMore on ResUsageSAWT When Collection and Logging Rates DifferHi Pierre,       Starting in 14.0 and up, there is no longer a CollectIntervals column in any ResUsage table.  In the ResusageSAWT table,  MailBoxDepth and WorkTypeInUs...
39018 Jun 2014 @ 10:02 PDTcarrie's blogStatistics collection recommendations – Teradata 14.0Hi Chris,   You don't really "set a table up" for stats collection, you just decide which stats you wish to collect and then build a script with collect stats statements for th...
38918 Jun 2014 @ 09:58 PDTcarrie's blogNew opportunities for statistics collection in Teradata 14.0Hi Nazy,   On 14.10 (and 14.0 as well) you no longer need to collect statistics on PARTITION, unless your table is a partitioned table.  For partitioned tables you should definitel...
38811 Jun 2014 @ 08:05 PDTcarrie's blogTeradata 13.10 Statistics Collection Recommendations You do not usually need statistics on a USI.  The optimizer knows a unique column is unique and that there will be one row for each distinct value, so statistics will not add an...
38716 May 2014 @ 02:49 PDTcarrie's blogAutomatic Throttles in Teradata 14.0 and 14.10Sravan,   I'm assuming you are on SLES 11, as you mention TIWM.  You are not allowed to deactivate the default rule set on an appliance, once you start using TIWM on SLES 11.  ...
38616 May 2014 @ 02:13 PDTcarrie's blogUtility Session Management - It's Inside the Database in Teradata 13.10! (UPDATED)Raghav, If you relying on MaxLoadTask to  manage the concurrency of utility jobs, you will never get the delay option.  When MaxLoadTask finds that a new load utility job would exce...
38516 May 2014 @ 01:53 PDTcarrie's blogUtility Session Management - It's Inside the Database in Teradata 13.10! (UPDATED)Ricky, The calculation used by session management is based on the number of AMPs in the system.  LAN configuration, or even the number of nodes, is not considered. Thanks, -Carrie
38407 May 2014 @ 08:19 PDTcarrie's blogNew opportunities for statistics collection in Teradata 14.0Srini,   The asterisk that you see in the first row of output for the HELP STATS under the "Column Names" column indicates that you are viewing row count of the table at the time t...
38329 Apr 2014 @ 08:10 PDTcarrie's blogStatistics collection recommendations – Teradata 14.0Even simple queries may benefit from stats collections whether or not you are using TASM.   And since statistics are collected on a table's columns/indexes, not on the ...
38225 Apr 2014 @ 12:44 PDTcarrie's blogStatistics collection recommendations – Teradata 14.01.  You can copy stats whether or not a column definition in the source table has changed.  Copied stats are for an unchanged column will be fine.   And if the column changed do...
38124 Apr 2014 @ 03:39 PDTcarrie's blogAutomatic Throttles in Teradata 14.0 and 14.10Hi Joe,   As far as I can see from your comments below, you are setting up the rule correctly.  There are no changes in 14.10 to how throttle enforcement options (Individual, Collective...
38021 Apr 2014 @ 04:27 PDTDatabaseStatistics Collection Recommendations for Teradata 12When data distribution is relatively uniform extrapolation can offer reasonably accurate estimate when statistics are out of date.  When stale statistics are detected, upward adjustments are m...
37914 Apr 2014 @ 04:39 PDTcarrie's blogChanges to the TASM AMP Worker Task Event in Teradata 13.10Requests are different from tasks.  The request comes from the user within a user session.  One request can be sumitted through a session at one time.     Usually, each A...
37804 Apr 2014 @ 04:30 PDTcarrie's blogRecommended Dictionary Statistics to Collect in Teradata 14.0There are no new recommendations for 14.10 in terms of which dictionary statistics to collect, so I would just continue to collect stats on these dictionary tables, and if you find additional dicti...
37724 Mar 2014 @ 08:53 PDTcarrie's blogUtility Throttles – You Won’t Regret It!Arif,   FastExport holds onto the utility slot until the end of the job, just as is the case with load utilities.  So what you are experiencing is expected behavior.  This is true ...
37624 Mar 2014 @ 08:52 PDTcarrie's blogNew opportunities for statistics collection in Teradata 14.0Vasudev,   I have written a blog posting that provides a summary of the AutoStats feature.  I believe your question is answered in that posting.  It is titled:   Easing...
37524 Mar 2014 @ 08:50 PDTDatabaseSkew-Sensitivity in the Optimizer: New in Teradata 12If you only have one row in your table, then it will appear skewed because only that one AMP will have data.  That is a normal situation. I don't see a problem with that.  There is no...
37424 Mar 2014 @ 08:47 PDTcarrie's blogRecommended Dictionary Statistics to Collect in Teradata 14.0Santanu,   I am not someone who works with PDCR or can explain detail about PDCR to you.   Best to ask that question to people from the Teradata Professional Services organization ...
37319 Mar 2014 @ 04:38 PDTcarrie's blogHow Resources are Shared in the SLES 11 Priority Scheduler1.   Just a point of clarity, in SLES 11 the allocation is to the workload, not a group of workloads as in SLES 10.   To decide the appropriate allocation (aka share percent), l...
37219 Mar 2014 @ 04:32 PDTcarrie's blogNew opportunities for statistics collection in Teradata 14.0Response to sk73:   1.  You do not need to recollect summary stats.  Summary stats are automatically collected on the table any time column/index stats are collected.    ...
37116 Mar 2014 @ 01:20 PDTcarrie's blogRecommended Dictionary Statistics to Collect in Teradata 14.0Santanu,   I don't recall reading that comment, or making that comment, so I'm not sure I can help answer your question.  I re-read this posting, but didn't see any ref...

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