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https://issues.apache.org/jira/browse/TAJO-744?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13974918#comment-13974918
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Alvin Henrick commented on TAJO-744:
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Hi Hyunsik ,
What does WITH CLAUSE means in ADD COLUMN PARTITION ?
Example :-- ALTER TABLE table_name [IF NOT EXISTS] ADD COLUMN PARTITION
(dt='2008-08-08', country='us') WITH (....)
DROP COLUMN PARTITION ? You think so we will have partition like this
(country != 'us') you have mentioned the possible operators in the syntax
[=|<|<=|>|>=|!=]
Example :-- ALTER TABLE table_name [IF EXISTS] DROP COLUMN PARTITION
(dt='2008-08-08', country='us');
Appreciate your help.
Thanks!
Warm Regards,
Alvin.
> ALTER TABLE ADD/DROP PARTITION statement
> ----------------------------------------
>
> Key: TAJO-744
> URL: https://issues.apache.org/jira/browse/TAJO-744
> Project: Tajo
> Issue Type: New Feature
> Components: catalog
> Affects Versions: 0.9
> Reporter: Hyunsik Choi
> Assignee: Alvin Henrick
> Fix For: 0.9
>
>
> Currently, Tajo does not manage partitioned directly. In Tajo, each partition
> is just a directory. For each query, a logical planner traverses matched
> directories in HDFS according to partition predicates.
> This approach is not efficient especially in the environment where the number
> of partitions are very large. It also makes partition management hard.
> Tajo should manage partitions directly by using ALTER TABLE ADD/DROP
> PARTITION statements. A number of partition entries should be stored in the
> underlying database that catalog uses.
> {code:title=Synopsis of ALTER TABLE ADD/DROP PARTITION}
> ALTER TABLE table_name [IF NOT EXISTS] ADD COLUMN PARTITION (key1 = 'val2',
> key2 = 'val2', ...) WITH ('prop_key' = 'prop_val', ...) LOCATION '...';
> ALTER TABLE table_name [IF EXISTS] DROP COLUMN PARTITION (key1
> [=|<|<=|>|>=|!=] 'val1');
> {code}
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