Improve performance of like queries. - response (5) by godspeeddeepak
Hello Dieter, I have been following your Posts for long time and have really helped a lot Question: Performance Tuning of SQLs results in reduction of Execution Time and CPU Utilization. What are...
View ArticleString Search in Teradata CLOB - forum topic by jupitarmn
Hi, Would you please anybody help me answering How to perform a string search in Teradata CLOB clumns? Thanks a lot for your help!!Forums: Database
View ArticleWhen does Dropping Stats help - forum topic by cnaveen05
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...
View ArticleNeed URGENT help on Update SQL tuning - forum topic by papgust
Hello All, I am new to this forum and Teradata as well. I am expected to tune a poor performing query but I have no idea how to proceed with understanding Explain plan and proceed with tuning. Can...
View ArticleWhen does Dropping Stats help - response (1) by Fred
This is a difficult question to answer, but here goes: a. 1 - The optimizer in effect is biased to assume that if you bothered to collect the stats, they must be relevant. a. 2 - If you have...
View ArticleSkew Ness - response (1) by Fred
Most of the tools and published queries calculate a "relative" skew value rather than some sort of absolute measure. If most AMPs have only table headers but a few AMPs also have a data row, the...
View ArticleUpdate statement with left outer join in from clause. - response (5) by...
Thanks Dieter, We have outer join used for mostly all updates and deletes on table. Client_gid is primary index for table and it is used along with other two joins for alias m. main purpose of all...
View ArticleNested OREPLACE leads to poor performance - forum topic by papgust
Hi, I am using this condition in UPDATE and SELECT statements and to process this condition takes a lot of time. The column 'recall_string' (Varchar(2000)) is in a table of 100 million records. Any...
View ArticleNested OREPLACE leads to poor performance - response (1) by CarlosAL
Use oTRANSLATE() instead. HTH Cheers. Carlos.
View ArticleSQL Query Performance - High Spool Space - forum topic by RAVISHA
Hello Experts, The following query is taking 200GB Spool space in the system and affects the overall performance. Any suggestion to improve the performance of the query. Select * from AAAA G, BBBBB V,...
View ArticleProblem While Joining Views: Intermediate spool being used in stead of View...
I am getting spool space error while trying to join 3-5 views that are accessing same underlying tables. Teradata optimizer is using the intermediate spool result in stead of the actual view output...
View ArticleNeed URGENT help on Update SQL tuning - response (1) by dnoeth
There's too much code: - You don't need COALESCE for comparison, as NULL always compares to unknown - You don't need IS NULL in WHERE, this is automatically added by the optimizer - Replace OREPLACE...
View ArticleCross tab - Pivot - response (2) by dnoeth
It's good that you found a solution on your own, but it would be nice if you could share it. Btw, your question is quite confusing, i still don't know what you actually wanted to do. Dieter
View ArticleSQL Query Performance - High Spool Space - response (1) by dnoeth
A Product Join involving large tables, might be due to the SQL or wrong statistics. It's hard to tell without additional information like DDL or at least PIs, row counts/statistics. And of course the...
View ArticleProblem While Joining Views: Intermediate spool being used in stead of View...
Hi Sayantan the optimizer sems to think this is the best option. Could you show the query plus explain? Statistics? Dieter
View ArticleOn Update Current_TimeStamp - forum topic by SHF
The customer is asking if there is a feature like 'On Update' ( as in SQL Server) to update the Current Timestamp in a table in Teradata? The customer is currently on 12.03 release. Table Definition...
View ArticleSynchronized scanning - response (10) by Shelley
the synchronized scanning is for pulling the data for building the hash join subtable, it is not part of the join itself. --Shelley--
View ArticleFull Table Scans - forum topic by usmans
Hi All, I would like to know where the information is about queries performing Full Table Scans or using Index Scans. If you could share the query that would be really great. This would really help me...
View ArticleHow to Calculate the total IO used by System for a particular week - response...
Any reply on the above?
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