Rebuild materialized view feature

Hive syntax

ALTER MATERIALIZED VIEW <name of view> REBUILD;

Hive example

In this example, first you set required properties. Next, you create Iceberg tables, a V1 table and a V2 table, from Hive. You insert data into the tables and create a materialized view of the joined tables. You insert some new values into one of the source tables, rendering the materialized view stale. Finally, you rebuild the materialized view.

drop table if exists tbl_ice;
drop table if exists tbl_ice_v2;

create external table tbl_ice(a int, b string, c int) stored by iceberg stored as orc tblproperties ('format-version'='1');
create external table tbl_ice_v2(d int, e string, f int) stored by iceberg stored as orc tblproperties ('format-version'='2');

insert into tbl_ice_v2 values (1, 'one v2', 50), (4, 'four v2', 53), (5, 'five v2', 54);

create materialized view mat1 as
select tbl_ice.b, tbl_ice.c, tbl_ice_v2.e from tbl_ice join tbl_ice_v2 on tbl_ice.a=tbl_ice_v2.d where tbl_ice.c > 52;

-- view should be empty
select * from mat1;

-- view is up-to-date, use it
explain cbo
select tbl_ice.b, tbl_ice.c, tbl_ice_v2.e from tbl_ice join tbl_ice_v2 on tbl_ice.a=tbl_ice_v2.d where tbl_ice.c > 52;

-- insert some new values to one of the source tables
insert into tbl_ice values (1, 'one', 50), (2, 'two', 51), (3, 'three', 52), (4, 'four', 53), (5, 'five', 54);

-- view is outdated, cannot be used
explain cbo
select tbl_ice.b, tbl_ice.c, tbl_ice_v2.e from tbl_ice join tbl_ice_v2 on tbl_ice.a=tbl_ice_v2.d where tbl_ice.c > 52;

explain cbo
alter materialized view mat1 rebuild;

alter materialized view mat1 rebuild;

-- view should contain data
select * from mat1;

-- view is up-to-date again, use it
explain cbo
select tbl_ice.b, tbl_ice.c, tbl_ice_v2.e from tbl_ice join tbl_ice_v2 on tbl_ice.a=tbl_ice_v2.d where tbl_ice.c > 52;