I need to alter data type of a column with out losing data in the table, how can i achieve this?
initially it is COL_A CHAR(8) CHARACTER SET LATIN CASESPECIFIC NOT NULL COMPRESS ('1 ','2 ')
now it should be COL_A CHAR(8) CHARACTER SET LATIN CASESPECIFIC NOT NULL COMPRESS ('1 ','2 ','3 ')
seems you don't want to change the data type but to update your compression list, correct?
add col_a char(8) COMPRESS ('1 ','2 ','3 ');
Just try it on a test table...