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https://issues.apache.org/jira/browse/HIVE-19253?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16582828#comment-16582828
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Alan Gates commented on HIVE-19253:
-----------------------------------

The first question that comes to mind is why are there two ways to specify 
something as external?  That's broken.

So in master I would simply ignore the external property everywhere and only 
use tableType.  We can mark it as a backward incompatible change.  We could 
also have the upgrade scripts look for any table with a property EXTERNAL and 
have it set the table type to external.

In 3, I would make sure that all new tables that are specified external become 
external (your item 1 above) but I wouldn't change the behavior of existing 
tables (that is, I wouldn't do 2 above).

The other question I have is how many people out there think they've created an 
external table when in fact they have not?

> HMS ignores tableType property for external tables
> --------------------------------------------------
>
>                 Key: HIVE-19253
>                 URL: https://issues.apache.org/jira/browse/HIVE-19253
>             Project: Hive
>          Issue Type: Bug
>          Components: Metastore
>    Affects Versions: 3.0.0, 3.1.0, 4.0.0
>            Reporter: Alexander Kolbasov
>            Assignee: Alexander Kolbasov
>            Priority: Major
>              Labels: newbie
>         Attachments: HIVE-19253.01.patch, HIVE-19253.02.patch, 
> HIVE-19253.03.patch, HIVE-19253.03.patch, HIVE-19253.04.patch, 
> HIVE-19253.05.patch
>
>
> When someone creates a table using Thrift API they may think that setting 
> tableType to {{EXTERNAL_TABLE}} creates an external table. And boom - their 
> table is gone later because HMS will silently change it to managed table.
> here is the offending code:
> {code:java}
>   private MTable convertToMTable(Table tbl) throws InvalidObjectException,
>       MetaException {
>     ...
>     // If the table has property EXTERNAL set, update table type
>     // accordingly
>     String tableType = tbl.getTableType();
>     boolean isExternal = 
> Boolean.parseBoolean(tbl.getParameters().get("EXTERNAL"));
>     if (TableType.MANAGED_TABLE.toString().equals(tableType)) {
>       if (isExternal) {
>         tableType = TableType.EXTERNAL_TABLE.toString();
>       }
>     }
>     if (TableType.EXTERNAL_TABLE.toString().equals(tableType)) {
>       if (!isExternal) { // Here!
>         tableType = TableType.MANAGED_TABLE.toString();
>       }
>     }
> {code}
> So if the EXTERNAL parameter is not set, table type is changed to managed 
> even if it was external in the first place - which is wrong.
> More over, in other places code looks at the table property to decide table 
> type and some places look at parameter. HMS should really make its mind which 
> one to use.



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