Can we update view in Teradata?

Can we update view in Teradata?

An existing view can be modified using REPLACE VIEW statement. Following is the syntax to modify a view.

How do I retrieve data from a SQL view?

CREATE VIEW view_name AS SELECT column1, column2….. FROM table_name WHERE [condition]; You can include multiple tables in your SELECT statement in a similar way as you use them in a normal SQL SELECT query.

Can we collect statistics on views in Teradata?

The Statistics Collection view lets you collect statistics on table columns and indexes. Collecting statistics on columns or indexes is important to producing query plans.

How do I view history in Teradata SQL Assistant?

Teradata SQL Assistant for Microsoft Windows User Guide Select View > Show History.

How do I change the view in Teradata?

A current view can be modified using the REPLACE VIEW statement. REPLACE VIEW redefines an existing view or, if the specified view does not exist, it creates a new view with the specified name. Following is the syntax to modify a view. The following example modifies the view Employee_View for adding additional columns.

What is updatable view?

An updatable view is a special case of a deletable view. A column of a view is updatable when all of the following rules are true: The view is deletable. The column resolves to a column of a table (not using a dereference operation) and the READ ONLY option is not specified.

Can we manipulate data in view?

You can manipulate a view just as you can manipulate a real table. The difference is that a view’s data doesn’t have an independent existence. The view derives its data from the table or tables from which you draw the view’s columns.

How can we retrieve data?

Reports and queries are the two primary forms of the retrieved data from a database. There are some overlaps between them, but queries generally select a relatively small portion of the database, while reports show larger amounts of data.

On which type of object statistics Cannot be collected?

Stats cannot be collected on columns with datatypes like BLOB, CLOB, JSON, XML and Period. If user tries to collect stats on these datatypes then it will fail with a error like below.

What is confidence level in Teradata?

Teradata Database is moderately certain that the estimated join cardinality is accurate. Statistics have been collected on the join columns of both the left and right relations. One relation in the join has Low confidence and the other has any of the following 3 confidence levels: Low. Index Join.

Where is Teradata history stored?

If a previous version is not found, a new, empty history database is created. The default path is C:\Documents and Settings\\Application Data\Teradata\SQL Assistant. C:\Users\\AppData\Roaming\Teradata\SQL Assistant.

Which command helps in redefining the view definition without dropping the existing view?

You can also use ALTER VIEW to define, modify, or drop view constraints. This statement does not change the definition of an existing view. To redefine a view, you must use CREATE VIEW with the OR REPLACE keywords.

How does the CREATE VIEW statement in Teradata work?

CREATE VIEW statement creates new view only. The use of LOCKING ROW prevents possible deadlocks occurring when two simultaneous primary index SELECTs are followed by an UPDATE, DELETE, or INSERT on the same row. If you want to create without LOCKING ROW, you can just specify the select query alone after the REPLACE VIEW statement as below.

How to create a recursive view in Teradata?

AS Syntax Example: AS … WITH NO DATA With Named Expressions Example: AS … WITH NO DATA With a Nonunique Secondary Index Example: AS … WITH DATA With a Nonunique Secondary Index Example: CREATE … AS Requests That Produce a Table With a Primary Index Example: CREATE …

How to create distinct form in Teradata Database?

CREATE TYPE (Distinct Form) RETURNS NULL ON NULL INPUT CREATE CAST and REPLACE CAST INSTANCE METHOD method_name ADD ATTRIBUTE attribute_name ACCOUNT = ‘account_string’ Example: Deleting a Database Example: Output with a UIF DROP DEFAULT JOURNAL TABLE

How to delete a Teradata Database in UIF?

INSTANCE METHOD method_name ADD ATTRIBUTE attribute_name ACCOUNT = ‘account_string’ Example: Deleting a Database Example: Output with a UIF DROP DEFAULT JOURNAL TABLE SET SESSION DEBUG FUNCTION SET SESSION FUNCTION TRACE