Thanks for your detailed explanations.
I'm not asking what the concepts of INTERNAL TABLE and EXTERNAL TABLE in hive,
I'm just confused what does the value "EXTERNAL_TABLE" in class
org.apache.hadoop.hive.TableType mean?
I create a table setting table type TableType.EXTERNAL_TABLE by calling hive
metastore api like this:
final HiveMetaStoreClient client = new HiveMetaStoreClient(c);
Table newTable = new Table();
newTable.setTableType(TableType.EXTERNAL_TABLE.toString());
...
client.createTable(newTable);
then I describe the created table with hive metastore api:
client.getTable("dbName", "tableName");
I can see that the table type is still "MANAGED_TABLE", is this a bug of
metastore api?
________________________________
发件人: Mich Talebzadeh <mich.talebza...@gmail.com>
发送时间: 2016年12月2日 5:29
收件人: user
主题: Re: Difference between MANAGED_TABLE and EXTERNAL_TABLE in
org.apache.hadoop.hive.metastore.TableType
Adding to Alan's points external tables are used often as a staging area. For
example, ingesting data from HDFS location on a daily basis and putting that
data into Hive managed tables. That location of that external table can change
pointing to a new HDFS directory created by say Flume etc through ALTER table
like below
ALTER TABLE ${DATABASE}.EXTERNALMARKETDATA set location
'hdfs://rhes564:9000/data/prices/${TODAY}';
HTH
Dr Mich Talebzadeh
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On 1 December 2016 at 17:53, Alan Gates
<alanfga...@gmail.com<mailto:alanfga...@gmail.com>> wrote:
Hive does not assume that it owns the data for an external table. Thus when an
external table is dropped, the data is not deleted. People often use this as a
way to load data into a directory in HDFS and then “cast” a table structure
over it by creating an external table with that directory as its location.
Alan.
> On Dec 1, 2016, at 06:15, Huang Meilong
> <ims...@outlook.com<mailto:ims...@outlook.com>> wrote:
>
> Hi all,
>
> I found an enum TableType in package org.apache.hadoop.hive.metastore. What's
> the difference between MANAGED_TABLE and EXTERNAL_TABLE?
>
> Will the table be an EXTERNAL TABLE with setting table type EXTERNAL_TABLE
> when creating table?
>
> I found the code to determine whether a table is an external table in
> MetaStoreUtils.java
> https://github.com/apache/hive/blob/master/metastore/src/java/org/apache/hadoop/hive/metastore/MetaStoreUtils.java#L1425
>
> I'm confused what is EXTERNAL_TABLE in TableType for?
