database - Create external tables without the EXTERNAL keyword? -


I am using the hive for work when I have created some external tables today, then i Forget about typing the external keyword, and it is like HighWQL: 

  make table year 2008/02/27 (some big areas, area should be begun, 'done by' 'ROE format, formatted areas' defined by the compilation items fixed by the commands of MAP 'Field' / Data / Content / year_2012_main 'entered in the form of' Prepared Field ':' Target ';   
 Then I tried to select  count (*) year_2012_main ; , and it worked well.  
 So, just out of curiosity, what is  external  with or without difference   
 
 
 A hive table that is not external is called a managed table. The main difference between an external and managed table in the hive is that when one Ahri is toppled table, its data (not deleted in your case / data / content / Wars_20l2_man), only metadata (number column, type the column, Terminator, etc.) were removed from the hive Metastor. When a managed table is removed, then both metadata and data are removed. I have always given priority to the table, because if the schema of my hive table changes, then I can just leave the external table and I can recreate another external table with the new schema on the same HDFS data. However, most of the changes in the schema (if not all) can now be made through the  optional table  or similar orders, so that my priority / priority is to use external tables to manage In comparison, there may be more worry in heritage. A contemporary  
 You can learn more about Terminology.

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