Tags for collect statistics
I have been experimenting with using MAXVALUELENGTH to make additional columns in multi-column stats significant. I have not been able to find anywhere a definition for what the maximum value is for this stats attribute.
collect statistics maxvaluelength
Tricky stats collection
Hi All,   I have a table that has 203 columns.The first three together are the PI for the table (say A,B,C).The other 200 columns are in the following pattern D001, DOO1_TXT, D002, D002_TXT, . . . . . D100, D100_TXT  
#performance #stats #teradata #DBA #tuning collect statistics
Change based threshold option for collect stats
Hi, I need to delete and reload a large table every day. Though there may not be huge change on the data. If I use below statement will it work? My understancding is collecting unnecessary stats can degrade overall performance. I don't wnat to collect stats if there is not more than 10% change in data.
collect statistics
Help Stats Displays Incorrect Statistics
Hello, I have recently encountered an issue where after running a COLLECT STATS statement on a table, the statistics displayed in the HELP STATS results aren't updating. I found that if I DROP STATS on the index or column and then re-collect stats, it will correctly display.
collect statistics help stats index column
Summary Statistics
Hi, What are differences between summary statistics and satistics? When we should opt for summary statistics instead of statistics?
collect statistics summary statistics
When sample statistics go wild
The accuracy of sample statistics has been greatly improved over the last Teradata releases. So I usually try to use sample stats on most of the big tables and I found them to be reliable on many columns, not only the officially recommended unique or nearly-unique columns, e.g. on DATEs.
collect statistics random amp sample
Statistics Collection Recommendations – Teradata 14.10, 15.0 and 15.10
Statistical information is vital for the optimizer when it builds query plans. But collecting statistics can involve time and resources. By understanding and combining several different statistics gathering techniques, users of Teradata can find the correct balance between good query plans and the time required to ensure adequate statistical information is always available. This recently-updated compilation of statistics collection recommendations are intended for sites that are on any of the Teradata Database 14.10, 15.0, or 15.10 software release levels. Some of these recommendations apply to releases earlier than Teradata Database 14.10 and some rely on new features available starting in Teradata Database 14.10.  Statistics collection functionality in the Teradata Database works the same in 14.10, 15.0 and 15.10 releases. For greater detail on collecting statistics for Teradata Database 14.10, see the orange book titled:  Teradata Database 14.10 Statistics Enhancements by Rama Krishna Korlapati. Contributors: Carrie Ballinger, Rama Krishna Korlapati, Paul Sinclair, September 11, 2014
collect statistics statistics database 14.10
Statistics Threshold Functionality 101
An earlier blog post focused on simple steps to get started using the Teradata 14.10 Automated Statistics Management (AutoStats) feature.  One of the new capabilities that AutoStats relies on when it streamlines statistics collection is the new “Threshold” option.  Threshold applies some intelligence about when statistics actually need to be re-collected, allowing the optimizer to skip some recollections.   Although you will probably want to begin relying on AutoStats when you get to 14.10, you don’t have to be using AutoStats to take advantage of threshold, as the two features are independent from one another.  This post will give you a simple explanation of what the threshold feature is, what default threshold activity you can expect when you get on 14.10, and what the options having to do with threshold do for you.  And you’ll get some suggestions on how you can get acquainted with threshold a step at a time.  
collect statistics statistics threshold teradata database 14.10
Collect Statistics
collect statistics stats collect statistics
When does Dropping Stats help
I have a long query generated from Microstrategy with lots of joins which was running our of spool space. I checked the query and confirmed that we had stats collected on all the join columns and stats were current. Then there was one column on which I dropped stats, it had both single and multi column stats after which the query started to run fine.
collect stats collect statistics Drop Stats Drop Statistics performance tuning