-- base table with null data DROP TABLE IF EXISTS base_tab; CREATE TABLE base_tab(a STRING, b STRING, c STRING, d STRING) STORED AS TEXTFILE; LOAD DATA LOCAL INPATH '../../data/files/null.txt' INTO TABLE base_tab; DESCRIBE EXTENDED base_tab; -- table with non-default null format DROP TABLE IF EXISTS null_tab1; EXPLAIN CREATE TABLE null_tab1(a STRING, b STRING) ROW FORMAT DELIMITED NULL DEFINED AS 'fooNull'; CREATE TABLE null_tab1(a STRING, b STRING) ROW FORMAT DELIMITED NULL DEFINED AS 'fooNull'; DESCRIBE EXTENDED null_tab1; SHOW CREATE TABLE null_tab1; -- load null data from another table and verify that the null is stored in the expected format INSERT OVERWRITE TABLE null_tab1 SELECT a,b FROM base_tab; dfs -cat ${system:test.warehouse.dir}/null_tab1/*; SELECT * FROM null_tab1; -- alter the null format and verify that the old null format is no longer in effect ALTER TABLE null_tab1 SET SERDEPROPERTIES ( 'serialization.null.format'='foo'); SELECT * FROM null_tab1; DROP TABLE null_tab1; DROP TABLE base_tab;