Statistics Threshold Functionality 101 - comment by zarrar.k85@gmail.com
Hi Carrie Is there a command to ignore the global threshold just once. Im afraid if use the statemnet level theshold I will change the stats collection threshold for that column for all later...
View ArticleStatistics Collection Recommendations – Teradata 14.10, 15.0 and 15.10 -...
Dinesh, The stats collection operation uses an access lock on the table and can be run when that table is being read or updated by a query. You can see this access lock if you do an explain on the...
View ArticleNew opportunities for statistics collection in Teradata 14.0 - comment by...
Hi Carrie, I believe summary statistics is not allowed on volatile tables but still it is receommended when you do help stats on which will throw an error "COLLECT failed. 3706:summary option is not...
View ArticleStatistics Threshold Functionality 101 - comment by carrie
Zarrar, If you wish to ignore the default global threshold capability (or your own established threshold percent or number of days) for just a single statistics collection statement, you can specify...
View ArticleNew opportunities for statistics collection in Teradata 14.0 - comment by carrie
Statistics on volatile tables are not saved in DBC.statstbl, as are other statistics on base tables. Volatile table stats are saved in memory for the given session. Currently, there is no slot in...
View ArticleStatistics Collection Recommendations – Teradata 14.10, 15.0 and 15.10 -...
Carrie, We are running on TD15.10. When I collect stats on a volatile table and execute an explain request after turning on "HELPSTAST" for session the optimizer is still recommending stats on the...
View ArticleStatistics Collection Recommendations – Teradata 14.10, 15.0 and 15.10 -...
Carrie, We have USEOUNT enabled for all our end table databases... But I was wondering if there will be a negative system impact if we turn it ON for ALL databases,, fro example staging tables...
View ArticleStatistics Collection Recommendations – Teradata 14.10, 15.0 and 15.10 -...
Genner, Statistics for volatile tables (VTTs) are handled differently from statistics on base tables. Statistics collected from VTTs are not saved in DBC.StatsTbl. They are saved in memory for the...
View ArticleStatistics Collection Recommendations – Teradata 14.10, 15.0 and 15.10 -...
Nazy, I have not heard of any issues with USECOUNT logging overhead being problematic. USECOUNT logging uses the same techniques as other DBQL collections. There is a USECOUNT DBQL cache that is...
View ArticleA Closer Look at How to Set up a Parsing-Only Workload - comment by geethareddy
Hi Carrie, Today i noticed an interesting case where SessionWDID=WDID=FinalWDID=Same Workload id number. We have parser only workload, let us say the WDID of PARSER-only workload=1. For one of the...
View ArticleA Closer Look at How to Set up a Parsing-Only Workload - comment by carrie
Geeta, There is an explanation for what you are seeing. Both Stored procedure CALL statements and Check Workload For statements are handled differently from other statements. They will always run in...
View ArticleA Closer Look at How to Set up a Parsing-Only Workload - comment by geethareddy
Good to know this.Thank you. Are there any other statements applicable for falling always in SessionWDID? I think there are few other statement types where they consume 0 CPU, just wanted to know if...
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Special Treatment For Users DBC and TDWM - blog entry by carrie
Cover Image: If you are user DBC or user TDWM and you log onto a Teradata Database, you might get treated somewhat differently than other users. This posting describes what user DBC and user TDWM do,...
View ArticleA Closer Look at How to Set up a Parsing-Only Workload - comment by carrie
Geeta, There are a couple of other statements types that will classify to the parsing-only workload. Commands that using only the parsing engine, such as SHOW and/or HELP commands may run at...
View ArticleHow to Calculate Your Max Number of Usable AMP Worker Tasks - comment by dins2k2
Carrie, Is there any way to calculate AWT consumed by a user/session? If no, can we use any colums to find out the same? Thanks, Dinesh
View ArticleSpecial Treatment For Users DBC and TDWM - comment by geethareddy
hi Carrie, I am trying to see the feasibility of defining the PROFILE for the system ids like DBC,TDWM,Crashdumps,Systemfe,SysAdmin,LockLogShredder...etc. As you said for DBC being a super-user we...
View ArticleStatistics collection recommendations – Teradata 14.0 - comment by kissu1960
Hi Carrie, Is there some harm if I define full statistics for some fields of the table and sample stats for the rest? I ask this because the client decided to collect sample statistics for all single...
View ArticleHow to Calculate Your Max Number of Usable AMP Worker Tasks - comment by carrie
Dinesh, There is no metric that reports the number of AWTs being used within a request or by a sessoin at any point in time, or even at the end of the request. The ResUsageSAWT table tells you the...
View ArticleSpecial Treatment For Users DBC and TDWM - comment by carrie
Geeta, In terms of setting up profiles for the system IDs like DBC,TDWM,Crashdumps,Systemfe,SysAdmin,LockLogShredder,, there is no special restriction for those users, but neither is there any real...
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