Changes between Version 3 and Version 4 of waue/2010/0128

Timestamp:

Jan 29, 2010, 5:40:58 PM (16 years ago)

Author:

waue

Comment:

--

waue/2010/0128

@@ -2 +2 @@
 #!html
 <div style="text-align: center; color:#151B8D"><big style="font-weight: bold;"><big><big>
-HBase Indexed Table
+HBase Primary Table  v.s. Indexed Table
 </big></big></big></div> <div style="text-align: center; color:#7E2217"><big style="font-weight: bold;"><big>
-Using HBase TableIndexed from Thrift with unique keys
+ Indexed Table = Secondary Index = Transactional HBase
 </big></big></div>
 }}}
 [[PageOutline]]
 
+= what is secondary index (distinguished to primary index) =
+
+Explain what is primary and secondary index.
+
+When you activate an object say ODS / DSO, the system automatically generate an index based on the key fields and this is primary index.
+
+In addition if you wish to create more indexes , then they are called secondary indexes.
+
+The primary index is distinguished from the secondary indexes of a table. The primary index contains the key fields of the table and a pointer to the non-key fields of the table. The primary index is created automatically when the table is created in the database.
+
+You can also create further indexes on a table. These are called secondary indexes. This is necessary if the table is frequently accessed in a way that does not take advantage of the sorting of the primary index for the access. Different indexes on the same table are distinguished with a three-place index identifier. 
+
+ = secondary index on hbase  =
+
 [http://kdpeterson.net/blog/2009/09/using-hbase-tableindexed-from-thrift-with-unique-keys.html]
 
 HBase is primarily a sorted distributed hash map, but it does support secondary keys through a contrib package called Transactional HBase. The secondary keys are provided by a component called TableIndexed.
 
+
+ = hbase's secondary index detail = 
 [http://mail-archives.apache.org/mod_mbox/hadoop-hbase-user/200908.mbox/%3C73d592f60908180339j3231f7f5w688260109ab3463@mail.gmail.com%3E]
-
-= what is secondary index (distinguished in primary index) =
-
-Explain the what is primary and secondary index.
-
-When you activate an object say ODS / DSO, the system automatically generate an index based on the key fields and this is primary index.
-
-In addition if you wish to create more indexes , then they are called secondary indexes.
-
-The primary index is distinguished from the secondary indexes of a table. The primary index contains the key fields of the table and a pointer to the non-key fields of the table. The primary index is created automatically when the table is created in the database.
-
-You can also create further indexes on a table. These are called secondary indexes. This is necessary if the table is frequently accessed in a way that does not take advantage of the sorting of the primary index for the access. Different indexes on the same table are distinguished with a three-place index identifier. 
-
- = hbase's secondary index detail = 
 
 {{{