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Tajo System Directory Hierarchy

The default system directory hierarchy is as follows:

[HDFS ROOT]
     |
     |-- tajo
     |     |
     |     |-- system
     |     |     |-- resource
     |     |             |-- system_conf.xml
     |     |-- warehouse
     |           |- [database  A]
     |           |        |- [table 1a]
     |           |        |- [table 2]
| |- [tabne N]
|
|-- tmp
 b]
     |           |
     |           |- [database ..]
     |           |
     |           |- [database  N]
     |                    |- [table x]
     |                    |- [table z]
     |
     |-- tmp
          |-- staging
                 |- q_1378468137418_0001
                 |           |- RESULT
                 |
                 |- q_1378468137418_0002
                 |           |- RESULT
                 |
                 |- q_1378468137418_000N

root directory

• Tajo  Tajo has a root directory (config key - 'tajo.rootdir')
• tajo tajo.rootdir is configurable.
• tajo tajo.rootdir contains a subdirectory 'system'.

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System directory

• system directory location is not configurable.
• system/resource directory contains 'system_conf.xml' which contains a global configuration used across a number of workers.

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Warehouse directory

• It contains a subdirectory per table.
• If you execute CREATE TABLE statement, the table is stored in here as a subdirectory.

staging directory

• It contains a temporary directory for each query.
• Each temporary directory has a query id as a directory name.
• For each query, query results are stored temporarily in here. But these results will be removed after a while.
• If a query is either CREATE TABLE or INSERT TABLE, the query result is moved to the warehouse directory.

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