Database Reference
In-Depth Information
Defining VIEWS in Impala
A
VIEW
in SQL is the result set of a stored query defined with a
SELECT
statement
or the
SELECT
portion of an
INSERT
statement. A
VIEW
can represent a subset of
data contained in a table by limiting the data set depending on the query statement.
In Impala, you can use
VIEW
to your advantage in the following ways:
• You can use
VIEW
in place of lengthy subqueries and repeating the same sub-
query in many queries
• Reduce maintenance by using
VIEW
in place of complicated queries across
multiple applications
• You can issue complex queries with a compact and simple syntax
• You can set up granular security in a table by limiting data access to only a
few columns
• You can set up aliases for tables, columns, and
JOIN
results with a more in-
formative name
Here are the common
VIEW
-specific statements in Impala:
•
CREATE VIEW
•
ALTER VIEW
•
DROP VIEW
