#DateWhereItemComment
12010 Apr 2012 @ 08:29 PDTcarrie's blogTeradata 13.10 Statistics Collection Recommendations The columns involved in the multicolumn stat will be ordered in the order they appear in the CREATE TABLE statement both when the statistics are collected and as they are represented in the histogr...
11906 Apr 2012 @ 08:51 PDTcarrie's blogTeradata 13.10 Statistics Collection Recommendations This is a list of recommendations only. Sorry, but this posting does not include accompanying scripts. In some cases, implementing these recommendations could probably be automated (collect...
11821 Mar 2012 @ 11:26 PDTcarrie's blogFastExport for Really Short Queries in Teradata 13.10FastExport with NoSpool option is only for requests returning a small number of rows. Spooling is a better choice for moderate or large volumes because it can ensure the response spoools are evenl...
11719 Mar 2012 @ 10:53 PDTcarrie's blogUtility Session Management - It's Inside the Database in Teradata 13.10! (UPDATED)Elle, The number of AMP worker tasks used by MultiiLoad depends on the phase of the load utility. MultiLoad (or the TPT load operator) uses 2 AWTs per AMP for the acquisition phase, and 1 AWT/...
11609 Mar 2012 @ 03:42 PSTcarrie's blogEnforcement Priority: Soft, Hard, or Just Window-Dressing?Hi Vinay, TDWM and Workload Designer both seem to enforce the rule that only tactical enforcement priority can be expedited. But I am not aware of any restriction about what resource partition ...
11509 Mar 2012 @ 11:09 PSTcarrie's blogEnforcement Priority: Soft, Hard, or Just Window-Dressing?Hi Vinay, On your release (12.0), a workload with a tactical enforcement priority can be placed in any resource partition you like, whether or not it is named "Tactical". The enforcement prior...
11428 Feb 2012 @ 08:23 PSTDatabaseAll-AMP Random AMP Sampling? Sure, Why Not!There are two different types of information produced by random AMP sampling: 1.) An estimate of the total rows in the table 2.) Extrapolation of total distinct values for each NUSI on the ...
11320 Feb 2012 @ 02:55 PSTcarrie's blogWhy collect PARTITION statistics on Non-Partitioned tables?Hi Mahesh. Good to hear from you! Row count calculation based on cylinder index does give an accurate row count. In addition, many CIs may already be in memory because they are used so ofte...
11216 Feb 2012 @ 03:46 PSTcarrie's blogPenalty Box Over-Population Hi Steve, You can try to delete the default RP, but you will not be allowed to. Neither can you delete or rename any of its performance groups. The default RP is special in that way, it is pr...
11116 Feb 2012 @ 09:34 PSTcarrie's blogUtility Session Management - It's Inside the Database in Teradata 13.10! (UPDATED)You can create multiple customized session management rules if you wish, to reflect the number of sessions you have determined prior to 13.10 to be optimal for different of your load jobs. While t...
11009 Feb 2012 @ 07:45 PSTcarrie's blogTwo Levels of Concurrency Control for Load Utilities in Teradata 13.10To create a utility throttle on FastLoad from an Appliance platform on 13.10 choose the sessions context, and select "Utility Limit" tab and then hit the "create utility limit" button. Pick a name...
10906 Feb 2012 @ 09:11 PSTcarrie's blogIf You’re Not Collecting Statistics on Your Dictionary Tables, Do It. Now.Hi Steven, Your a step ahead of me! While it was true in the past that you could not collect statistics on un-hashed tables in the data dictionary, that restriction was lifted in release 13.0 ...
10802 Feb 2012 @ 08:06 PSTDatabaseStatistics Collection Recommendations for Teradata 12Thanks, Dieter!
10701 Feb 2012 @ 04:05 PSTDatabaseStatistics Collection Recommendations for Teradata 12Laeeq, You are correct about the re-collection rules being somewhat different for partitioned tables (PPI). If growth is greater than 10% in any one partition, it is advisable to recollect sta...
10630 Jan 2012 @ 01:52 PSTcarrie's blogNumber of AMP Worker Tasks used by Archive Utility I am not familiar with the PDCRDATA database, so unfortunately, I can't offer any specific suggestions. Backup performance is generally influenced by the size of the data being archived and the...
10523 Jan 2012 @ 03:54 PSTcarrie's blogTwo Levels of Concurrency Control for Load Utilities in Teradata 13.10Your default setting assumptions are correct. However, a second enforcement is also going to be taking place internally. That is on AMP worker tasks used by the utilities. Only 60% of the ...
10420 Jan 2012 @ 11:16 PSTcarrie's blogUtility Session Management - It's Inside the Database in Teradata 13.10! (UPDATED)Sorry, I misspoke when I said utility throttles were new in Teradata 12.0. They were actually introduced in Teradata V2R6.1. However, it was not until Teradata 12.0 that they were able to cleanly...
10320 Jan 2012 @ 11:14 PSTcarrie's blogUtility Session Management - It's Inside the Database in Teradata 13.10! (UPDATED)There are two different features that need to be understood separately. 1.) Utility concurrency control; and 2.) Session Management. Utility control: Since Teradata 12.0, utility concurren...
10218 Jan 2012 @ 08:36 PSTcarrie's blogHow to set a System-Level CPU limit for Capacity-on-DemandI don't have a clear yes or no answer to your question. There are some types of requests that do not completely honor a CPU limit. For example, an ALTER TABLE statement will not completely ho...
10116 Jan 2012 @ 04:06 PSTcarrie's blogReserving AMP Worker Tasks? Don’t let the Parameters Confuse You!Good questions. Unfortunately there is no way to track AWT usage by individual query. Other than you can look at the explain and make an educated guess, based on parallel steps being present. ...
10013 Jan 2012 @ 11:19 PSTcarrie's blogYet ANOTHER List…Post-Expansion Workload Management ChecklistA CPU limit works like a thermostat. The defined limit has to be exceeded before the logic kicks in to begin slowing down work that it controls so that CPU usage falls under the CPU limit. So yo...
9913 Jan 2012 @ 11:15 PSTcarrie's blogHow to set a System-Level CPU limit for Capacity-on-DemandYou are not able to place a CPU limit on a user or on an application. A CPU limit can only be placed on an allocation group, on a resource partition, or at the system level. Only those 3 levels. ...
9821 Dec 2011 @ 08:04 PSTcarrie's blogUtility Session Management - It's Inside the Database in Teradata 13.10! (UPDATED)Hi JK, Utility session management is available through Viewpoint for both full TASM and appliance sites. Appliance sites don’t get the “workload” part of TASM or the events or the state ...
9713 Dec 2011 @ 02:45 PSTkeep it simpleExtract and Analyse Database Object DependenciesHi Ulrich, Good posting! There are several reasons why SHOW is not supported for a stored procedure. One reason is that you may execute only a subset of the DML requests for a given exe...
9608 Dec 2011 @ 03:30 PSTcarrie's blogUtility Session Management - It's Inside the Database in Teradata 13.10! (UPDATED)Teradata load utlilities have robust error handling and restart capabilities. In most cases a load utility job can be restarted after a database failure and reset, a load process error or failure,...

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