Teradata Studio: Teradata's Administration Toolkit Teradata Studio is an administrative tool to help Teradata customers administer their Teradata and Aster Database systems. Teradata SQL Assistant - Version 14.01 This session presents a general overview of the features of the Teradata SQLA tool.
Teradata Studio Express Java Error
- Teradata Tutorial
- Teradata Basics
Create a Database & Table in Teradata Studio. 15.11 - Teradata Studio User Guide - Teradata Studio prodname Teradata Studio vrmrelease 15.11 createddate May 2016 category User Guide featnum B035-2041-056K. Teradata offers job-based online training for Teradata products to help you do more with data. Sign up for world-class training courses and online content. Teradata Studio is an administration toolkit that helps users to create and administer database objects.
- Teradata Advanced
- Teradata Useful Resources
- Selected Reading
EXPLAIN command returns the execution plan of parsing engine in English. It can be used with any SQL statement except on another EXPLAIN command. When a query is preceded with EXPLAIN command, the execution plan of the Parsing Engine is returned to the user instead of AMPs.
Examples of EXPLAIN
Consider the table Employee with the following definition.
Some examples of EXPLAIN plan are given below.
Full Table Scan (FTS)
When no conditions are specified in the SELECT statement, then the optimizer may choose to use Full Table Scan where each and every row of the table is accessed.
Example
Following is a sample query where the optimizer may choose FTS.
When the above query is executed, it produces the following output. As can be seen the optimizer chooses to access all AMPs and all rows within the AMP.
Unique Primary Index
When the rows are accessed using Unique Primary Index, then it is one AMP operation.
When the above query is executed, it produces the following output. As can be seen it is a single-AMP retrieval and the optimizer is using the unique primary index to access the row.
Unique Secondary Index
Teradata Studio 16
When the rows are accessed using Unique Secondary Index, it’s a two amp operation.
Example
Consider the table Salary with the following definition.
Consider the following SELECT statement.
When the above query is executed, it produces the following output. As can be seen the optimizer retrieves the row in two amp operation using unique secondary index.
Additional Terms
Following is the list of terms commonly seen in EXPLAIN plan. Rc car simulator free for mac.
.. (Last Use) …
A spool file is no longer needed and will be released when this step completes.
Digiprog3 manual. .. with no residual conditions …
All applicable conditions have been applied to the rows.
.. END TRANSACTION …
Transaction locks are released, and changes are committed.
Teradata Studio Express
.. eliminating duplicate rows ..
Duplicate rows only exist in spool files, not set tables. Doing a DISTINCT operation.
.. by way of a traversal of index #n extracting row ids only …
A spool file is built containing the Row IDs found in a secondary index (index #n)
Teradata Studio Guide
.. we do a SMS (set manipulation step) …
Combining rows using a UNION, MINUS, or INTERSECT operator.
.. which is redistributed by hash code to all AMPs.
Redistributing data in preparation for a join.
.. which is duplicated on all AMPs.
Duplicating data from the smaller table (in terms of SPOOL) in preparation for a join.
.. (one_AMP) or (group_AMPs)
Twixtor mac. Indicates one AMP or subset of AMPs will be used instead of all AMPs.
Comments are closed.