tajo-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From jihoon...@apache.org
Subject tajo git commit: TAJO-1705: Update document for index support.
Date Wed, 06 Jan 2016 07:47:00 GMT
Repository: tajo
Updated Branches:
  refs/heads/branch-0.11.1 8e4b8b110 -> 15f715a1b


TAJO-1705: Update document for index support.


Project: http://git-wip-us.apache.org/repos/asf/tajo/repo
Commit: http://git-wip-us.apache.org/repos/asf/tajo/commit/15f715a1
Tree: http://git-wip-us.apache.org/repos/asf/tajo/tree/15f715a1
Diff: http://git-wip-us.apache.org/repos/asf/tajo/diff/15f715a1

Branch: refs/heads/branch-0.11.1
Commit: 15f715a1b412687a7e81f99551f2d39b84394c2c
Parents: 8e4b8b1
Author: Jihoon Son <jihoonson@apache.org>
Authored: Wed Jan 6 16:46:52 2016 +0900
Committer: Jihoon Son <jihoonson@apache.org>
Committed: Wed Jan 6 16:46:52 2016 +0900

----------------------------------------------------------------------
 CHANGES                                         |  2 ++
 tajo-docs/src/main/sphinx/index/future_work.rst |  3 +-
 tajo-docs/src/main/sphinx/index/how_to_use.rst  | 32 +++++++++++++-------
 tajo-docs/src/main/sphinx/index/types.rst       |  4 +--
 tajo-docs/src/main/sphinx/index_overview.rst    |  6 ----
 5 files changed, 26 insertions(+), 21 deletions(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/tajo/blob/15f715a1/CHANGES
----------------------------------------------------------------------
diff --git a/CHANGES b/CHANGES
index 5c453e4..ab1ceb7 100644
--- a/CHANGES
+++ b/CHANGES
@@ -81,6 +81,8 @@ Release 0.11.1 - unreleased
 
   TASKS
 
+    TAJO-1705: Update document for index support. (jihoon)
+
     TAJO-2028: Refining Hive Integration document including typo.
     (Jongyoung Park via jihoon)
 

http://git-wip-us.apache.org/repos/asf/tajo/blob/15f715a1/tajo-docs/src/main/sphinx/index/future_work.rst
----------------------------------------------------------------------
diff --git a/tajo-docs/src/main/sphinx/index/future_work.rst b/tajo-docs/src/main/sphinx/index/future_work.rst
index c6ec47d..976a34f 100644
--- a/tajo-docs/src/main/sphinx/index/future_work.rst
+++ b/tajo-docs/src/main/sphinx/index/future_work.rst
@@ -2,7 +2,6 @@
 Future Works
 *************************************
 
-* Providing more index types, such as bitmap and HBase index
+* Supporting more index types, such as bitmap and HBase index
 * Supporting index on partitioned tables
-* Supporting the backup and restore feature
 * Cost-based query optimization by estimating the query selectivity
\ No newline at end of file

http://git-wip-us.apache.org/repos/asf/tajo/blob/15f715a1/tajo-docs/src/main/sphinx/index/how_to_use.rst
----------------------------------------------------------------------
diff --git a/tajo-docs/src/main/sphinx/index/how_to_use.rst b/tajo-docs/src/main/sphinx/index/how_to_use.rst
index c67af66..a56979d 100644
--- a/tajo-docs/src/main/sphinx/index/how_to_use.rst
+++ b/tajo-docs/src/main/sphinx/index/how_to_use.rst
@@ -1,18 +1,19 @@
-*************************************
+*****************
 How to use index?
-*************************************
+*****************
 
--------------------------------------
+---------------
 1. Create index
--------------------------------------
+---------------
 
-The first step for utilizing index is index creation. You can create index using SQL (:doc:`/sql_language/ddl`)
or Tajo API (:doc:`/tajo_client_api`). For example, you can create a BST index on the lineitem
table by submitting the following SQL to Tajo.
+The first step for utilizing index is to create an index. You can create an index using SQL
(:doc:`/sql_language/ddl`) or Tajo API (:doc:`/tajo_client_api`).
+For example, the following SQL statement will create a BST index on the lineitem table.
 
 .. code-block:: sql
 
      default> create index l_orderkey_idx on lineitem (l_orderkey);
 
-If the index is created successfully, you can see the information about that index as follows:
::
+If the index is created successfully, you can see the index information as follows: ::
 
   default> \d lineitem
 
@@ -48,17 +49,18 @@ If the index is created successfully, you can see the information about
that ind
 
 For more information about index creation, please refer to the above links.
 
--------------------------------------
+-----------------------------
 2. Enable/disable index scans
--------------------------------------
+-----------------------------
 
-When an index is successfully created, you must enable the index scan feature as follows:
+Reading data using index is disabled by default.
+So, exploiting the created index, you need a further step, enabling 'index scan' as following:
 
 .. code-block:: sql
 
      default> \set INDEX_ENABLED true
 
-If you don't want to use the index scan feature anymore, you can simply disable it as follows:
+If you don't want to use index scan anymore, you can simply disable it as follows:
 
 .. code-block:: sql
 
@@ -66,4 +68,12 @@ If you don't want to use the index scan feature anymore, you can simply
disable
 
 .. note::
 
-     Once the index scan feature is enabled, Tajo currently always performs the index scan
regardless of its efficiency. You should set this option when the expected number of retrieved
tuples is sufficiently small.
+     Once index scan is enabled, Tajo will perform 'index scan' if possible. In some cases,
it may cause performance
+     degradation. If you always want to get better performance, you should either enable
or disable 'index scan'
+     according to selectivity. Usually, the performance gain of index will increase when
the selectivity is low.
+
+---------------------------
+3. Index backup and restore
+---------------------------
+
+Tajo currently provides only the catalog backup and restore for index. Please refer to :doc:`/backup_and_restore/catalog`
for more information about catalog backup and restore.
\ No newline at end of file

http://git-wip-us.apache.org/repos/asf/tajo/blob/15f715a1/tajo-docs/src/main/sphinx/index/types.rst
----------------------------------------------------------------------
diff --git a/tajo-docs/src/main/sphinx/index/types.rst b/tajo-docs/src/main/sphinx/index/types.rst
index 457f453..23b378c 100644
--- a/tajo-docs/src/main/sphinx/index/types.rst
+++ b/tajo-docs/src/main/sphinx/index/types.rst
@@ -2,6 +2,6 @@
 Index Types
 *************************************
 
-Currently, Tajo supports only one type of index, ``TWO_LEVEL_BIN_TREE``, shortly ``BST``.
The BST index is a kind of binary search tree which is extended to be permanently stored on
disk. It consists of two levels of nodes; a leaf node indexes the keys with the positions
of data in an HDFS block and a root node indexes the keys with the leaf node indices.
+Currently, Tajo supports only one type of index, ``TWO_LEVEL_BIN_TREE``, shortly ``BST``.
The BST index is a kind of binary search tree which is extended to be permanently stored on
disk. It consists of two levels of nodes; a leaf node indexes the keys with the offsets to
data stored on HDFS, and a root node indexes the keys with the offsets to the leaf nodes.
 
-When an index scan is started, the query engine first reads the root node and finds the search
key. If it finds a leaf node corresponding to the search key, it subsequently finds the search
key in that leaf node. Finally, it directly reads a tuple corresponding to the search key
from HDFS.
\ No newline at end of file
+When an index scan is started, the query engine first reads the root node and finds the search
key. If it successfully finds a leaf node corresponding to the search key, it subsequently
finds the search key in that leaf node. Finally, it directly reads a tuple corresponding to
the search key from HDFS.
\ No newline at end of file

http://git-wip-us.apache.org/repos/asf/tajo/blob/15f715a1/tajo-docs/src/main/sphinx/index_overview.rst
----------------------------------------------------------------------
diff --git a/tajo-docs/src/main/sphinx/index_overview.rst b/tajo-docs/src/main/sphinx/index_overview.rst
index a42931b..73a436e 100644
--- a/tajo-docs/src/main/sphinx/index_overview.rst
+++ b/tajo-docs/src/main/sphinx/index_overview.rst
@@ -4,12 +4,6 @@ Index (Experimental Feature)
 
 An index is a data structure that is used for efficient query processing. Using an index,
the Tajo query engine can directly retrieve search values.
 
-This is still an experimental feature. In order to use indexes, you must check out the source
code of the ``index_support`` branch::
-
-  git clone -b index_support https://git-wip-us.apache.org/repos/asf/tajo.git tajo-index
-
-For the source code build, please refer to :doc:`getting_started`.
-
 The following sections describe the supported index types, the query execution with an index,
and the future works.
 
 .. toctree::


Mime
View raw message