Index creation and Table level of AMP size in Teradata

How to create a table using unique primary index:

CREATE MULTISET TABLE [databasename].[tablename]

(                                   

  col_1   INTEGER,

  col_2   VARCHAR(50)

)

UNIQUE PRIMARY INDEX ( col_1 );

How to create a table using primary index:

CREATE MULTISET TABLE [databasename].[tablename]

(                                  

  col_1   INTEGER,

  col_2   VARCHAR(50)

)

PRIMARY INDEX ( col_1 );

Example 3: Checking data distribution of given columns on the AMP

SELECT HASHAMP(HASHBUCKET(HASHROW([columnlist]))),COUNT(*) FROM [databasename].[tablename]

GROUP BY 1 ORDER BY 2 DESC;

Storage of a table for each AMP

SELECT vproc, CurrentPerm

FROM DBC.TableSize

WHERE DatabaseName = '[databasename]'

AND TableName = '[tablename]'

ORDER BY 1;

Skewness of a table

SELECT TableName,SUM(CurrentPerm) AS CurrentPerm,SUM(PeakPerm) AS PeakPerm,

       CAST((100 - (AVG(CurrentPerm)/MAX(CurrentPerm)*100)) AS INTEGER) AS SkewFactor

FROM DBC.TableSize

WHERE DatabaseName='[databasename]'

AND TableName= '[tablename]'

GROUP BY 1;