How to do it...

1. Create a table with two columns.
2. Choose PI as a date column, which is skewed:

CREATE volatile MULTISET TABLE MY_SKEW_TABLE 
(
 ITEM_ID DECIMAL(18,0) NOT NULL,
 Today_DT DATE NOT NULL
)
PRIMARY INDEX (Today_DT)
on commit preserve rows;

1.  Insert the first day of data (100,000 rows).
2.  Check the distribution of your PI; try this query:

/**Hash AMP which row query**/
LOCKING ROW FOR ACCESS
SELECT HASHAMP(HASHBUCKET(HASHROW(Today_DT))) AS WhichAMP
,COUNT(*) AS RowsPerAMP
    FROM MY_SKEW_DB.MY_SKEW_TABLE
GROUP BY 1
ORDER BY 2 DESC
;

1. Sort the data in the following format to check which AMP holds the most number of rows:

1. Now, to resolve this you can use the same query and use other columns of the table in composite form, or single, to get the better distribution:

CREATE MULTISET TABLE MY_NONSKEW_DB.MY_NONSKEW_TABLE 
(
 ITEM_ID DECIMAL(18,0) NOT NULL,
 Today_DT DATE NOT NULL
) PRIMARY INDEX (Today_DT,ITEM_ID)
;