here is a table
CREATE TABLEtable_v2(date_partitiondate NULL COMMENT "xxx",date_timedatetime NULL COMMENT "xx",is_someint(11) NULL COMMENT "xxxx",uuidhll HLL_UNION NULL COMMENT "xxxx", INDEX xxx_index_date (date_partition) USING BITMAP COMMENT 'xx', INDEX xxxx_is_some (is_some) USING BITMAP COMMENT 'xxx', ) ENGINE=OLAP AGGREGATE KEY(date_partition,date_time,is_some) COMMENT "OLAP-index" PARTITION BY RANGE(date_partition) (PARTITION p20200710 VALUES [('1970-01-01'), ('2020-07-10'))) PROPERTIES ( "replication_num" = "3", "in_memory" = "false", "storage_format" = "V2" );

when schema chage alter table table_v2 modify column is_some TINYINT
then errCode = 2, detailMessage = Can not change INT to TINYINT
but document
5) 目前支持以下类型的转换（精度损失由用户保证） TINYINT/SMALLINT/INT/BIGINT 转换成 TINYINT/SMALLINT/INT/BIGINT/DOUBLE。