You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@cassandra.apache.org by "lichenglin (JIRA)" <ji...@apache.org> on 2011/01/10 08:17:46 UTC

[jira] Commented: (CASSANDRA-1958) query slow in million columns of one key

    [ https://issues.apache.org/jira/browse/CASSANDRA-1958?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12979494#action_12979494 ] 

lichenglin commented on CASSANDRA-1958:
---------------------------------------

we think the point is  
    Iterator collated = IteratorUtils.collatedIterator(comparator, iterators);
     //in org.apache.cassandra.db.ColumnFamilyStore.getTopLevelColumns()

SliceQueryFilter  calls reducedColumns.next() in collectReducedColumns() to get minValue.
Each call get minValue,just like Bubble Sort.

why not to sort after merge iterators?

> query slow in million columns of one key
> ----------------------------------------
>
>                 Key: CASSANDRA-1958
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-1958
>             Project: Cassandra
>          Issue Type: Bug
>    Affects Versions: 0.6.5
>         Environment: three nodes with SUSE and 2G JVM.
>            Reporter: lichenglin
>
> We get all records in 200 ms with 10,000 columns of one key, but 4 seconds  with 100,000 columns, and we fear for 1,000,000.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.