Hi Guys,
 
I have a doubt regarding the confidence levels of the optimizer in the explain plan.
 
Below is the scenario that i created:
1. Created 2 tables Location and Employee with unique primary indexes on EmpNo column
 

Hi All,
I tried below for an explain plan of a table Table1 and got some head scratching questions:

Explain Select * from DB1.Table1;

Output:

-------------

1) First, we lock DB1.Table1 for access.

2) Next, we do an all-AMPs RETRIEVE step from

     DB1.Table1 by way of an all-rows scan

Does the optimizer treat a query differently when the object names in the query are fully qualified vs. when they are not fully qualified ?
I came across a query which gives one explain plan when the views referenced by the query are fully qualified i.e. <databasename>.<viewname>

Hi,

is the presence of Rowhash match scan in the explain plan an indicator for Fastpath Merge join?

Thanks

Hi all,

I have a doubt on the explain query generated for a simple count(*) query.

SELECT COUNT(*) FROM databasename.tablename 

The Explain Plan generated from a V13 system is as below

Hi

can someone explain me the concept of Synchronized scanning which often shows up in the Explain plan.

Thanks

Hi,

I am firing a explain plan query on a table (Item) in TD.The third step of the explain plan reads like:

3) We do an All-AMP RETRIEVE step from DBNAME.Item by way of index # 4 "DBNAME.Item.PartKey=328" is built locally with no resisual conditions into Spool 1 (group_amps), which is built locally on the AMPs.The size of spool 1 is....

Note: A Non-Unique Secondary Index (NUSI) is defined on ParKey column of Item table.

The question is: What does index#4 mean in the explain plan.Does it refer to the NUSI?

Hi,

I am new to teradata , trying to understand how does teradata does joins internally.

I am going through the teradata documentation and i have the below question.

table structures used in query:
CREATE SET TABLE TFACT.Employee ,FALLBACK
(Employee_Number INTEGER NOT NULL,
Location_Number INTEGER,
Dept_Number INTEGER,
Emp_Mgr_Number INTEGER,
Job_Code INTEGER,
Last_Name CHAR(20),
First_Name VARCHAR(20),
Salary_Amount DECIMAL(10,2))
UNIQUE PRIMARY INDEX ( Employee_Number )
INDEX ( Job_Code )
INDEX ( Dept_Number );

CREATE SET TABLE TFACT.Department ,FALLBACK

Hi All,
I am doin an innerjoin on two tables with a condition say
A.col1=B.col1, when I do explain on the query it shows that a product join is been made between the tables though there is a join condition.Can any body explain me why it's happening and how to avoid the product join.

Thanks in Advance,
Sri