Statistics collection recommendations – Teradata 14.0 - comment by carrie
Christer, There is no problem collecting sampled statstics on some columns and full statistics on others on the same table. Full stats are often a better choice when there is noteable skew in the...
View ArticleStatistics Collection Recommendations – Teradata 14.10, 15.0 and 15.10 -...
Is there a provision to recollect stats based on their names ? COLLECT STATS <Statistics Name> ON TABLENAME;
View ArticleStatistics Collection Recommendations – Teradata 14.10, 15.0 and 15.10 -...
Hi Sanji, Yes, you can recollect statistics by name, if a name exists. This is particularly useful if you have multicolumn statistics. From page 7 of the orange book titled: Teradata Database 14.10...
View ArticleSpecial Treatment For Users DBC and TDWM - comment by geethareddy
Thank you for the advice.
View ArticleClik here to view.
Things that Run in the Session Workload - blog entry by carrie
Cover Image: You’ll probably want to skip over this posting. Unless you’re curious about some of the more obscure workload classification conventions used by TASM and TIWM.In a previous blog posting...
View ArticleA Closer Look at How to Set up a Parsing-Only Workload - comment by carrie
The purpose of the Parsing-only workload is to elevate the priority of CPU usage on the parsing engine when a session logs on or a query undergoes parsing/optimization. This CPU usage on the parsing...
View ArticleConverting CPU Seconds, Old Node Type to New Node Type - comment by gskaushik
Hi Carrie, Kindly inform on how to calculate the TPERF of a system from RESUSAGE tables. Thanks in advance.
View ArticleConverting CPU Seconds, Old Node Type to New Node Type - comment by carrie
Subramanian, I'm not familiar with the formula or calculations involved in determing the TPERF value for a given hardware node. I believe those are internally determined by Teradata Engineering....
View ArticleHow Resources are Shared in the SLES 11 Priority Scheduler - comment by...
Hi Carrie, Nice and detail explanation. Thanks. Does SLES 11 consume more system CPU? We recently moved to SLES 11 priority scheduler. After the migration, we see good amount of increase in...
View ArticleHow Resources are Shared in the SLES 11 Priority Scheduler - comment by carrie
Amir, It is difficult to quantify CPU consumption changes between SLES 10 and SLES 11 because the accounting is completely different in SLES 11. But in general, most sites experience some increase...
View ArticleNew, Simplified Approach to Parsing Workload Selection - comment by sureshbadam
Carrie, Thanks for greate articles / blogs on DBQL. I have a situation that is somewaht disscussed above but not matching with my case. Here is my example wdid=? sessionwdid=41 and statement=SELECT. I...
View ArticleNew, Simplified Approach to Parsing Workload Selection - comment by carrie
Suresh, Could this be a PREPARE statement, if it is coming from ODBC. Based on ODBC settings, queries will get submitted twice. The first time for parsing and second rime for actual execution. You...
View ArticleExpediting Express Requests - comment by StevenSchmid
Hi Carrie I'm currently working on a 13.10 system, which is due to be upgraded to 15.0 at the end of the year. We are using Viewpoint 15.0 The system is currently CPU bound and frequently goes into...
View ArticleExpediting Express Requests - comment by carrie
Steven, I am assuming you are on SLES 10, as you are on 13.10 database software. The two settings you mention ("Reserved AWT" and "Max Expedited AWTs") are not set at the workload level. They are...
View ArticleExpediting Express Requests - comment by StevenSchmid
Hi Carrie Thanks for your detailed reply. Yes, we are on SLES10 TD13.10, will upgrade to SLES11 sometime in the new year, after the 15.0 upgrade. I have found the Orange book you mentioned, very...
View ArticleHow Resources are Shared in the SLES 11 Priority Scheduler - comment by sghanw
Hi Carrie, I have one doubt we are on TD 14.10 and SLES11, currently if a query is running on Step 7 which usually takes 30min to complete and if DBA team manually change workload of that query from...
View ArticleExpediting Express Requests - comment by carrie
Steven, SLES 10 and SLES 11 work in a similar way when it comes to the AWT work types different work messages will be assigned. In SLES 10, if a workload has a tactical enforcement priority it is...
View ArticleHow Resources are Shared in the SLES 11 Priority Scheduler - comment by carrie
Sachin, If you move a query to a different workload in the middle of a step, the new priority will take effect immediately. If you don’t think giving a higher priority to the query is as effective...
View ArticleStatistics Collection Recommendations – Teradata 14.10, 15.0 and 15.10 -...
Hi Carrie, Need a clarification on how skipping stats works. 1. We had a traditional automated stats collection process where 10% was crietieria which we replaced with new feature of...
View ArticleStatistics Collection Recommendations – Teradata 14.10, 15.0 and 15.10 -...
Also one more question how is this stats skip related to stats_mngr process ?
View Article