#DateWhereItemComment
24519 Mar 2013 @ 08:10 PDTcarrie's blogUsing the ResUsageSAWT table to Monitor AMP Worker TasksYuri,   Your comments make sense to me.    Thanks, -Carrie
24415 Mar 2013 @ 03:31 PDTcarrie's blogNew opportunities for statistics collection in Teradata 14.0Yes, you can collect statistics inside of a stored procedure.   Thanks, -Carrie
24314 Mar 2013 @ 08:11 PDTcarrie's blogStatistics collection recommendations – Teradata 14.0Hi Norbert, There are no plans to change that convention.  It is by design that you can only choose one column ordering for a multicolumn statistics.  This is in order to avoi...
24211 Mar 2013 @ 02:34 PDTcarrie's blogChanges to the TASM AMP Worker Task Event in Teradata 13.10GS, The maximum number of reserved AMP worker tasks that you can specify has been at 20 since Teradata 12.0.1 release.  It has not changed in 13.10. If you select a reserve of 9 for expedite...
24127 Feb 2013 @ 08:59 PSTcarrie's blogTeradata 13.10 Statistics Collection Recommendations This is an optional recommendation. The only reason you might want to collect on both as a multicolumn statistic is if a given PI value exists in multiple partitions, and you do sliding window and...
24027 Feb 2013 @ 08:57 PSTcarrie's blogPenalty Box Over-Population Mack, Unfortunately, that information is not made available. You can only guess by looking at the explain text. The ResusageSPS table will tell you AMPs worker tasks used by the workload, ...
23927 Feb 2013 @ 08:55 PSTcarrie's blogUtility Session Management - It's Inside the Database in Teradata 13.10! (UPDATED)Vinay, I sent you an email directly in response. The specifics involved in your recent comment are probably more suited to an offline discussion. I think there are some confusions concerni...
23825 Feb 2013 @ 09:10 PSTcarrie's blogTeradata 13.10 Statistics Collection Recommendations Statistics collection statements never produce a total estimated time. It has always been that way. So you don’t want to try to use estimated time for classification of those types of requests....
23725 Feb 2013 @ 09:09 PSTcarrie's blogCPU Limits at Multiple LevelsSPMA does not report on available CPU, but rather it reports on consumed CPU. For CPU consumed, you don't want to add in CPUIdle, as that is time CPU is not being consumed. The same is true for C...
23625 Feb 2013 @ 09:07 PSTcarrie's blogAre AMP Worker Tasks used by FastExport in Response Mode?I am not able to help respond to this question, as this is not in my area of experience. Please post it one of the Teradata forums or open an incident with the support center. Thanks, -Carrie
23525 Feb 2013 @ 09:05 PSTcarrie's blogReserving AMP Worker Tasks? Don’t let the Parameters Confuse You!The reserve is for each AMP. AMP worker tasks are AMP-specific, not node-specific. You are correct that if you specify a reserve of 20 each AMP will have 42 AMP worker tasks taken out of the una...
23422 Feb 2013 @ 01:35 PSTcarrie's blogUtility Session Management - It's Inside the Database in Teradata 13.10! (UPDATED)GS Oh, There are many reasons why skew might be high on one load job, but not another. It depends on the characteristics of the data being loaded and which AMPs the data is going to. More dat...
23322 Feb 2013 @ 01:32 PSTcarrie's blogUtility Session Management - It's Inside the Database in Teradata 13.10! (UPDATED)Abhijit, FastExport will hold a utility slot until the response mode is complete. Thanks, -Carrie
23222 Feb 2013 @ 08:22 PSTcarrie's blogWhat is the Estimated Processing Time? Sorry my example got all squished together, let me try to make that clearer: DBQLogTbl _ _ QryLogTDWM 34 _ _ _ _ _ _ _ _0.033715 15,697 _ _ _ _ _ 15.697290 12 _ _ _ _ _ _ _ _ 0.012486 156...
23122 Feb 2013 @ 08:20 PSTcarrie's blogWhat is the Estimated Processing Time? Hi Andrew, 1. You are correct. TDWMEstTotalTime and EstProcTime fields of the dbqlogtbl table are in milliseconds and seconds respectively. TDMWEstTotalTime is kept internally as millisec...
23014 Feb 2013 @ 10:14 PSTcarrie's blogNew opportunities for statistics collection in Teradata 14.0The optimizer chooses whether or how to use pre-aggregation or rollups at the time of the statistics collection statement. I do not have any insights I can share with you concerning how those algo...
22912 Feb 2013 @ 08:05 PSTcarrie's blogUsing the ResUsageSAWT table to Monitor AMP Worker TasksRahul, this is a good question. My perspective on flow control is pretty stricft: You want to avoid it. It is always a sign of congestion, and generally it should be a red flag for you to take...
22811 Feb 2013 @ 08:32 PSTcarrie's blogHow to Calculate Your Max Number of Usable AMP Worker TasksIf your question is how many AWTs will be available for unexpedited user-intitiated work if you select a reserve count of 20, here is the math on that: You start with 80 AWTs per AMP, and then t...
22706 Feb 2013 @ 11:08 PSTcarrie's blogTeradata 13.10 Statistics Collection Recommendations Hi Mark, Empty partitions are not an issue if PARTITION stats are collected. PARTITION stats are important because they tell the optimizer how many and which partitions are empty. So you shoul...
22606 Feb 2013 @ 11:07 PSTcarrie's blogTeradata 13.10 Statistics Collection Recommendations Suhail, PARTITION stats counts the rows in each partition of the table, so the optimizer knows how many are empty, and if not empty, how full. This is used for estimating I/O costs for the opti...
22504 Feb 2013 @ 09:56 PSTcarrie's blogUtility Session Management - It's Inside the Database in Teradata 13.10! (UPDATED)Roopalini, In terms of total number of sessions, you are correct that each PE is limited to 120, so you can multiply the number of PEs by 120 and that is the max number of sessions your system c...
22401 Feb 2013 @ 01:14 PSTcarrie's blogNew opportunities for statistics collection in Teradata 14.0When you drop a single-column index, the single-column statistics will remain and can be used by the optimizer in generating a plan. The stats are still valid. However, if you have an index ...
22330 Jan 2013 @ 09:25 PSTcarrie's blogDatabase Tasks that Run on the Parsing Engine Hi Dan, AMP worker task work type definitions are not held anywhere in the database and there is no control record that describes them as far as I know. I'm assuming that that type of detail is...
22229 Jan 2013 @ 11:38 PSTcarrie's blogNew opportunities for statistics collection in Teradata 14.0What you can do in 14.0 is to recollect SUMMARY stats on the table after each load winder. SUMMARY stats on the table are very quick and carry information that will help the optimizer produce extr...
22129 Jan 2013 @ 11:33 PSTcarrie's blogHow to Calculate Your Max Number of Usable AMP Worker TasksYou second paragraph is correct. If you have 100 AWTs per AMP, 24 will be used for the standard reserve pools, leaving 76 (100 - 24 = 76). Add 6 to that 76 (because you can use three each for the...

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