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Posted to commits@impala.apache.org by ar...@apache.org on 2019/04/11 18:25:16 UTC
[impala] 04/06: IMPALA-8391: [DOCS] ALTER TABLE RENAME now renames
the underlying Kudu TABLE
This is an automated email from the ASF dual-hosted git repository.
arodoni pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/impala.git
commit 65837f82e19be13367edeb1dbb6daec442189817
Author: Alex Rodoni <ar...@cloudera.com>
AuthorDate: Tue Apr 9 16:29:18 2019 -0700
IMPALA-8391: [DOCS] ALTER TABLE RENAME now renames the underlying Kudu TABLE
Change-Id: I704a0623a05166e5f636b6c1063e9feffb58e65b
Reviewed-on: http://gerrit.cloudera.org:8080/12975
Reviewed-by: Alex Rodoni <ar...@cloudera.com>
Tested-by: Impala Public Jenkins <im...@cloudera.com>
---
docs/topics/impala_tables.xml | 59 +++++++++++++++++++++++--------------------
1 file changed, 32 insertions(+), 27 deletions(-)
diff --git a/docs/topics/impala_tables.xml b/docs/topics/impala_tables.xml
index 0da7955..b2b6a71 100644
--- a/docs/topics/impala_tables.xml
+++ b/docs/topics/impala_tables.xml
@@ -283,44 +283,49 @@ under the License.
<data name="Category" value="Kudu"/>
</metadata>
</prolog>
-
<conbody>
<p>
- Tables stored in Apache Kudu are treated specially, because Kudu manages its data independently of HDFS files.
- Some information about the table is stored in the metastore database for use by Impala. Other table metadata is
- managed internally by Kudu.
+ Tables stored in Apache Kudu are treated specially, because Kudu
+ manages its data independently of HDFS files. Some information about the
+ table is stored in the metastore database for use by Impala. Other table
+ metadata is managed internally by Kudu.
</p>
-
- <p> When you create a Kudu table through Impala, it is assigned an
+ <p>
+ When you create a Kudu table through Impala, the table is assigned an
internal Kudu table name of the form
<codeph>impala::<varname>db_name</varname>.<varname>table_name</varname></codeph>.
You can see the Kudu-assigned name in the output of <codeph>DESCRIBE
FORMATTED</codeph>, in the <codeph>kudu.table_name</codeph> field of
- the table properties. The Kudu-assigned name remains the same even if
- you use <codeph>ALTER TABLE</codeph> to rename the Impala table or move
- it to a different Impala database. You can issue the statement
- <codeph>ALTER TABLE <varname>impala_name</varname> SET
- TBLPROPERTIES('kudu.table_name' =
- '<varname>different_kudu_table_name</varname>')</codeph> for the
- external tables created with the <codeph>CREATE EXTERNAL TABLE</codeph>
- statement. Changing the <codeph>kudu.table_name</codeph> property of an
- external table switches which underlying Kudu table the Impala table
- refers to. The underlying Kudu table must already exist. </p>
-
- <p>In practice, external tables are typically used to access underlying
+ the table properties.
+ </p>
+ <p> For Impala-Kudu managed tables, <codeph>ALTER TABLE ...
+ RENAME</codeph> renames both the Impala and the Kudu table. </p>
+ <p> For Impala-Kudu external tables, <codeph>ALTER TABLE ...
+ RENAME</codeph> renames just the Impala table. To change the Kudu
+ table that an Impala external table points to, use <codeph>ALTER TABLE
+ <varname>impala_name</varname> SET TBLPROPERTIES('kudu.table_name' =
+ '<varname>different_kudu_table_name</varname>')</codeph>. The
+ underlying Kudu table must already exist. </p>
+ <p>
+ In practice, external tables are typically used to access underlying
Kudu tables that were created outside of Impala, that is, through the
- Kudu API. </p>
-
+ Kudu API.
+ </p>
<p>
- The <codeph>SHOW TABLE STATS</codeph> output for a Kudu table shows Kudu-specific details about the layout of the table.
- Instead of information about the number and sizes of files, the information is divided by the Kudu tablets.
- For each tablet, the output includes the fields
- <codeph># Rows</codeph> (although this number is not currently computed), <codeph>Start Key</codeph>, <codeph>Stop Key</codeph>, <codeph>Leader Replica</codeph>, and <codeph># Replicas</codeph>.
- The output of <codeph>SHOW COLUMN STATS</codeph>, illustrating the distribution of values within each column, is the same for Kudu tables
+ The <codeph>SHOW TABLE STATS</codeph> output for a Kudu table shows
+ Kudu-specific details about the layout of the table. Instead of
+ information about the number and sizes of files, the information is
+ divided by the Kudu tablets. For each tablet, the output includes the
+ fields <codeph># Rows</codeph> (although this number is not currently
+ computed), <codeph>Start Key</codeph>, <codeph>Stop Key</codeph>,
+ <codeph>Leader Replica</codeph>, and <codeph># Replicas</codeph>. The
+ output of <codeph>SHOW COLUMN STATS</codeph>, illustrating the
+ distribution of values within each column, is the same for Kudu tables
as for HDFS-backed tables.
</p>
-
- <p conref="../shared/impala_common.xml#common/kudu_internal_external_tables"/>
+ <p
+ conref="../shared/impala_common.xml#common/kudu_internal_external_tables"
+ />
</conbody>
</concept>