Interested to Buy Any Domain ? << Click Here >> for more details...
1.what is activity count?
2.what is skew factor?
how it's working explain brefily
- 5 Answers
- 32901 Views
- Satyam, I also Faced
- E-Mail Answers
Answers were Sorted based on User's Feedback
Answer / vinay sir(datawarehousing tech
ActivityCount:The number of rows processed in the previous
sql statement it defines.
EG: if there is a table party is having 14 rows then
SELECT * FROM PARTY;
.ACTIVITYCOUNT= 14
Skewfactor:
It tells the distribution of the rows.
-->If uniformly distributed(normal distribution) skew
factor is 0.
-->Skew factor is the reversal of Parallel efficiency.(if
skew factor is 10 then parallel effciency is 90).
There is aformula to identify the skewness.
Please find the below.
SELECT TableName,SUM(CurrentPerm) AS
CurrentPerm,SUM(PeakPerm) AS PeakPerm,(100 -
(AVG(CurrentPerm)/MAX(CurrentPerm)*100)) AS SkewFactor
FROM Dbc.TableSize
WHERE DataBaseName = 'VINAY'
GROUP BY 1 ORDER BY 1
| Is This Answer Correct ? | 13 Yes | 2 No |
Answer / yuvaevergreen
1. >> activity count indicates the no of rows affected/processed by the last request(no of rows returned to bteq from teradata).
2. >> skewness refers to the distribution of rows on the amps.
>> If some AMPs are having more rows and some very less, then skewness would be high. This would affect the parallelism.
3. Following query gives the skewness for all tables.
SELECT ts.DatabaseName
,ts.TableName
,td.CreateTimeStamp AS Created
,td.LastAlterTimeStamp AS LastAltered
,td.AccessCount
,td.LastAccessTimeStamp AS LastAccess
,SUM(ts.CurrentPerm) AS CurrentPerm
,SUM(ts.PeakPerm) AS PeakPerm,
(100 - (AVG(ts.CurrentPerm)/MAX(ts.CurrentPerm)*100)) AS SkewFactor
FROM DBC.TableSize ts
JOIN DBC.Tables td
ON ts.DatabaseName = td.DatabaseName
AND ts.TableName = td.TableName
GROUP BY 1,2,3,4,5,6;
| Is This Answer Correct ? | 6 Yes | 0 No |
Answer / tdguy
activity count - rows processed by sql.
skew factor - distribution of data over the amps.
when the distribution is highly skewed, the amp working may
be affected, which inturn affects parallelism.
| Is This Answer Correct ? | 3 Yes | 0 No |
Answer / tdguy
Hi Anjum,
As far as I know, "FROM" option in "IMPORT" mload
command can be used to load specific no of records. I would
suggest to use FROM and THRU option to load.
| Is This Answer Correct ? | 1 Yes | 0 No |
Answer / anjum
one question please....how do we load firsr five record
through mload?
| Is This Answer Correct ? | 0 Yes | 0 No |
What is the difference between fastload and multiload? Which one is faster?
Explain and compare pros and cons of snow flake schemas?
Mention the procedure via which, we can run Teradata jobs in a UNIX environment.
How to Extract data from multiple legacy systems?
What is spool space?
What is database exceptions in teradata?
where we can use the delimiter in mload? pls let me know
1)WHAT IS THE EXACT DIFFERENCE BETWEEN TERADATA AND ORACLE? 2)MOST OF THE COMPANIES ARE USING TARA DATA FOR "DWH PROJECTS" ONLY? WHY?
6 Answers Bank Of America, Wipro,
what are the roles and responsibilities of teradata DBA ?
teradata support to automatically increase the character length or not?
write a query following data. 123.45 is input.write a query after decimal (ex:.45) load into database ?how it possible?
How to view every column and the columns contained in indexes in teradata?
Teradata 
