If i have a hive table, which is an external table, and have my "log files" being read into it, if a new file is imported into the hdfs and the file has a new column, how can i get hive to handle the old files w/o the new column, if I do an alter adding column into the hive table. So example, i have a few files w/ these fields:
empid, empname, deptno and so my hive table CREATE EXTERNAL TABLE IF NOT EXISTS Employee ( empid BIGINT ,empname string deptno BIGINT ) ROW FORMAT DELIMITED FIELDS TERMINATED BY '\t' STORED AS TEXTFILE LOCATION 'hdfs://namenode1/employee/'; but if I have a new file imported into the hdfs directory w/ a new column empid, empname, deptno, salary I can't do an alter of the employee table adding salary b/c of the historical files. I used external tables b/c I wanted the table to dynamically get all the log files into hive table, when a new file is generated. I know the long way is basically adding fields through all the old files, but prefer of a more scalable way to do this. Anyone know of any? Thanks
