Creating Database Views
You can create database views using the Trino 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 new View | CREATE VIEW vast."mybucket/myschema".myview COMMENT "view comment" AS (SELECT col1, col2 FROM vast."mybucket/myschema".mytable WHERE col1 > 0) |
List Views in the database | Trino has no direct way of listing views. You can use workarounds like this example, where all views have the suffix "_view". SHOW TABLES FROM vast."mybucket/myschema" LIKE '%_view%' |
Show details for a View | SHOW CREATE VIEW vast."mybucket/myschema".myview |
Redefine a View | ALTER VIEW vast."mybucket/myschema".myview AS (SELECT col1, col2 FROM vast."mybucket/myschema".mytable WHERE col1 > 0 AND col2 > 0) |
Query using a View | SELECT * FROM vast."mybucket/myschema".myview WHERE v_col2 > 5 ORDER BY v_col1 |
Rename a View | ALTER VIEW vast."mybucket/myschema".myview RENAME TO vast."mybucket/myschema".mynewview |
Limitations
View properties are not supported
Nested data types are not supported
User-defined column names and comments are lost if the schema of the query changes when redefining a view