[ 
https://issues.apache.org/jira/browse/CASSANDRA-5682?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Jonathan Ellis resolved CASSANDRA-5682.
---------------------------------------

    Resolution: Not A Problem

bq. I think that the Cassandra needs the compaction function for secondary 
index .

Possible since CASSANDRA-4464

> When the Cassandra delete keys in secondary Index?
> --------------------------------------------------
>
>                 Key: CASSANDRA-5682
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-5682
>             Project: Cassandra
>          Issue Type: Improvement
>          Components: Core
>    Affects Versions: 2.0.1
>         Environment: normal x86 PC (i3 CPU + 4GB ram) + Ubuntu 12.04
>            Reporter: YounwooKim
>            Priority: Minor
>
> How can i reduce the size of secondary index?
> Obviously, I delete many keys, and tried flush, compact, cleanup, 
> rebuild_index using nodetool. However, i can't reduce the size of secondary 
> index. ( Of course, the size of table(Primary key) is reduced. )
> Therefore, I found out the hint from the Cassandra source code, and I guess a 
> feature of secondary index deletion.
> 1) When I request deletion of key, and the key is in the sstable(not in the 
> memtable), the Cassandra doesn't insert the tombstone to the sstable for 
> secondary index.( Unlike the table )
> ( from AbstractSimpleColumnSecondaryIndex.delete() function. )
> 2) After scaning the secondary index, the tombstone is maded in secondary 
> index.
> ( from KeysSearcher.getIndexedIterator() function. It is called by index scan 
> verb. )
> 3) Cleanup command in nodetool is used to delete out of range keys. ( Cleanup 
> command don't care about deleted keys )
> ( from CompactionManager.doCleanupCompaction() function. )
> After this, I scan deleted keys using 'Where' clause, and I can reduce the 
> size of secondary index. I think that it is only one way to reduce the size 
> of secondary index.
> Is this a correct conclusion? I can't found related articles and other 
> methods. 
> I think that the Cassandra needs the compaction function for secondary index .



--
This message was sent by Atlassian JIRA
(v6.1#6144)

Reply via email to