DW: Teradata Data warehousing Pictorial Diagram

ODS : Operational data source

Teradata Load Server: Where data received from ODS is stored in Teradata load server.

RDBMS: This is the database, which interacts with Tearadata Load server.

Comments

Post a Comment

Popular posts from this blog

SQL for Quantile Function in Teradata

Image
A Quantile is used to divide rows into a number of categories or grouping of roughly the same number of rows in each group. Quantile Function The percentile is the QUANTILE most commonly used in business. This means that the request is based on a value of 100 for the number of partitions SELECT Product_ID1, Sales_Date1, Daily_Sales1 ,QUANTILE(100, Daily_Sales1 ) AS "Quantile1" FROM Sales_Table WHERE Product_ID1 < 3000 AND Sales_Date1 > 1000930 ; The calculation is percentile for every row in the Sales table on Daily sales.
Read more

All You Need NULL Value Functions

Image
The below are the Null value functions in Tearadata. One is "NVL" and another one is "NVL2". These two functions are part of Teradata SQL . NVL -The NVL function replace null value with a string or numeric value. This is the functionality is same as Teradata function NULLIF. It requires two arguments. If the value is not null, it will not do anything. The best SQL Null functions  NVL function:  SELECT NVL (NULL,'USA'), NVL('SPAIN','USA'); ----------- USA SPAIN Also Read: Top 70 Teradata Interview Questions The NVL2 function : Returns one of two specified values (arguments#2 and Arguments#3) based on weather the first arguments in NULL or not. It requires three arguments. The rule is as follows: If expression 1 is not null, expression 2 is returned If expression 1 is null, expression 3 is returned The best NVL2 example SELECT NVL2(NULL,'FRANCE','SPAIN'), NVL2('ENGLAND','FRANCE','SPAIN...
Read more

3 Uses of SAMPLE function in Teradata

Image
Usage-1 It returns a rows randomly from Teradata database. Syntax for SAMPLE function: SAMPLE [WITH REPLACEMENT]    [RANDOMIZED ALLOCATION]                  [WHEN <condition>  THEN]                  {<number-of-rows> | <percentage>}    […,<number-of-rows> | <percentage>]                  [ELSE {<number-of-rows> |    <percentage }   END] Usage 2 It allows the user to get absolute number of rows or percentage of rows. Usage 3 It also allows the rows to get from multiple samples How to get random rows from a table: SELECT * from sample_table SAMPLE 5; How to get certain percentage of rows: SELECT * from sample_table SAMPLE .30; How to get multiple SAMPLE data from a single tables with out duplicates: SELECT * from sample_...
Read more