Spark Client Supported Features

Creating Database Views

You can create database views using the Spark client when connected to a VAST Database. Views allow you to save queries and re-use them in other queries.

Database views are stored queries that present a part of a VAST Database. They are created and managed using the client application and stored in a table in the database itself. They can be used in other queries on the database.

Action	Example
Create a view	`CREATE VIEW ndb.mybucket.myschema.myview (v_col1 COMMENT "column with a comment", v_col2) comment "view comment" as select col1, col2 from ndb.mybucket.myschema.mytable where col1 > 0`
List views	`SHOW VIEWS FROM ndb.mybucket.myschema`
Show details for a view	`DESCRIBE TABLE EXTENDED ndb.mybucket.myschema.myview`
Rename a view	`ALTER VIEW ndb.mybucket.myschema.myview RENAME TO mybucket.myschema.mynewview ALTER VIEW ndb.mybucket.myschema.myview RENAME TO mynewview`
Redefine a view	`ALTER VIEW ndb.mybucket.myschema.myview as select col1, col2 from ndb.mybucket.myschema.mytable where col1 > 0 and col2 > 0`
Using a view in a query	`select * from ndb.mybucket.myschema.myview where v_col2 > 5 order by v_col1`

Limitations

View properties are not supported
Full table names must be used in view queries
User-defined column names and comments are lost if the schema of the query changes when redefining a view