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
VIEWin place of lengthy subqueries and repeating the same subquery in many queries - Reduce maintenance by using
VIEWin 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
JOINresults with a more informative name
Here are the common VIEW-specific statements in Impala:
CREATE VIEWALTER VIEWDROP VIEW
..................Content has been hidden....................
You can't read the all page of ebook, please click here login for view all page.