change column type snowflake
alter table TABLE_NAME add column TEMP_COLUMN TIMESTAMP_LTZ(9); update TABLE_NAME t1 set t1.TEMP_COLUMN = TO_TIMESTAMP_LTZ(t2.TIMESTAMP_NTZ_COLUMN_NAME) from TABLE_NAME t2 where t1.TEMP_COLUMN = t2.TIMESTAMP_NTZ_COLUMN_NAME // if you don't want troubles create a new copy of table and use SWAP WITH instead alter table aws_config rename column TIMESTAMP_NTZ_COLUMN_NAME to TIMESTAMP_NTZ_COLUMN_NAME_OLD; alter table aws_config rename column TEMP_COLUMN to TIMESTAMP_NTZ_COLUMN_NAME; alter table aws_config drop column TIMESTAMP_NTZ_COLUMN_NAME_OLD
