If I have a fulltext index on a field, say "First Name + Last Name" and I create the following materialized view:
CREATE MATERIALIZED VIEW names AS SELECT * FROM table
Am I able to use the fulltext index when querying the materialized view, or is it necessary that a FTS index is rebuilt if I'm to run a query that searches against that MV?
Think of a materialized view as its own table, which is populated when the view is created or refreshed. When the materialized view is being populated, it will use whatever indexes are on the source tables which are relevant. However, when you query the materialized view, you're not interacting with any of those source tables, and so none of those indexes can come into play.
If you want to do fulltext queries or the like on a materialized view, you'll want to create a relevant index on the materialized view itself.
Related
I am trying to understand but its not obvious to me in the documentation of Azure SQL DW, if you materialize a view and any of the base tables of the view is being updated with data or data is deleted / truncated, will this affect what is accessible in the materialized view or will what was created in the materialized view at execution persist?
A Materialized View persists the data returned from the view definition query and automatically gets updated as data changes in the underlying tables.
I tried All the operation you mentioned in Question on the base table of materialized view It is updating the view according to the changes perform on base table materialized view without restrictions.
Sample data
Created Materialized view on table
Updated data in base table and performed select operation on view
Deleted data from base table and performed select operation on view
Inserted data in base table and performed select operation on view
After every update on base table Materialized view is getting updated automatically.
I have an existing view I need materialized. Ideally, I would drop the view and create a materialized one, but dropping the view would require a cascade drop and that would create a lot more work.
Is there an expression to change the view to a materialized one?
I need to create an index on a view in mariaDB. Is this possible?
Note that, I can't create an index on tables since admininstrator permissions are not given to access tables.
No, you cannot create indexes on a View in MariaDB.
Indeed, Views are not real relations, but simply aliases on relations (tables).
You could have created indexes on a Materialized View but MariaDB does not implement (in a native way) Materialized Views as of today.
I have three sites,one site contians the employees table, while the other sites have materialized view of employees table .
This is how i created the materialized views on the other sites.
CREATE MATERIALIZED VIEW employeesMV
REFRESH FAST
FOR UPDATE
AS
SELECT * FROM manager.employees#managerlink;
so i just want to know how to update the master table employees after i make changes such as (insert or update) on the materialized view.
Thank you in advance.
By default, materialized view can't be updated. However, if you use FOR UPDATE clause, you can do it, but those changes aren't reflected in MV's source table. Moreover, as soon as you refresh the MV, changes you've made will be lost.
Advanced replication covers it, but Oracle says that it is deprecated in 12cR1.
There's a walkthrough on Vinayaga Consultancy's blog, Updatable Materialized View, based on Oracle 11.2 (source) and 10.2 (target database) so - have a look. It isn't that trivial at all.
I create a indexed view View1 on Table1 and Table2 and have instead of trigger and after trigger on Table1 that use of View1. It seem that data of View1 not change when I use this view on instead of trigger and after trigger. But I want to use View1 with new data when use this view on after trigger. How can I do it. It should be noted that I use with Noexpand hint when use indexed view (when don't use with noexpand hint in SQL Server 2008 R2 act this indexed view such as no indexed view).
The indexed view is updated after all triggers on the base tables are executed. You can see that in the query plan. There will be only one clustered index update on the view.
However, you can create INSTEAD OF triggers on the view and then make all your operations on the indexed view. However,there are some restrictions when updating/inserting/deleting through an updateable view. You can read about them here.
Note that views allow only INSTEAD OF triggers, not AFTER too.
The most important thing to know about updating indexed views is that any modifications, including UPDATE, INSERT, and DELETE statements, must reference columns from only one base table.