Help Center/ MapReduce Service/ Component Operation Guide (LTS)/ Using HetuEngine/ Common HetuEngine SQL Syntax/ DDL Syntax/ DROP MATERIALIZED VIEW
Updated on 2024-10-25 GMT+08:00
View PDF
Share

DROP MATERIALIZED VIEW

Syntax

DROP MATERIALIZED VIEW [IF EXISTS] view_name

Description

This statement is used to delete a materialized view. If the view to be deleted does not exist and the if exists parameter is used, no error occurs.

If a materialized view is deleted, metadata and table data associated with it will also be deleted.

A materialized view will fail to delete if some data (metadata or table data) has been deleted before the materialized view is deleted.

Example

  • Create a table. 
    hetuengine:tpcds_2gb> create table t1 (id int, c1 varchar);
hetuengine:tpcds_2gb> Insert into t1 values (1,'abc'), (2,'abc2'), (3,'abc3'), (4,'abc4'), (5,'abc5'), (6,'abc6');
  • Create a materialized view. 
    hetuengine:tpcds_2gb> create materialized view mv.tpcds.t1 as select c1 from t1 where id <7;
  • Delete a specified view. If the view does not exist, an error occurs. 
    hetuengine:tpcds_2gb> drop materialized view mv.tpcds.t1;
Query 20211206_095415_00003_k4wwu failed: line 1:1: MATERIALIZED VIEW 'mv.tpcds.t1' does not exist
  • Delete a specified materialized view with the if exists parameter set. If the view exists, it will be deleted. If the view does not exist, no error occurs. 
    hetuengine:tpcds_2gb> drop materialized view if exists mv.tpcds.t1;
DROP MATERIALIZED VIEW
Parent topic: DDL Syntax