[
https://issues.apache.org/jira/browse/CASSANDRA-9989?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16596229#comment-16596229
]
Benedict edited comment on CASSANDRA-9989 at 8/29/18 11:46 AM:
---------------------------------------------------------------
Thanks Jay.
Unfortunately this breaks the {{isWellFormed}} test, and [I've added a special
case|https://github.com/belliottsmith/cassandra/tree/9989] to {{LongBTreeTest}}
to check this. In the case of a tree of size 20, we produce a child node that
is smaller than {{FAN_FACTOR / 2}}. To avoid this, we need to calculate a
mid-point where we decrement the size, which is just a cleaner generalisation
of splitting the final two nodes (and instead of two loops, we can have a
single conditional move inside the loop, to subtract on the correct child)
was (Author: benedict):
Thanks Jay.
Unfortunately this breaks the {{isWellFormed}} test, and I've added a special
case to {{LongBTreeTest}} to check this. In the case of a tree of size 20, we
produce a child node that is smaller than {{FAN_FACTOR / 2}}. To avoid this,
we need to calculate a mid-point where we decrement the size, which is just a
cleaner generalisation of splitting the final two nodes (and instead of two
loops, we can have a single conditional move inside the loop, to subtract on
the correct child)
> Optimise BTree.Buider
> ---------------------
>
> Key: CASSANDRA-9989
> URL: https://issues.apache.org/jira/browse/CASSANDRA-9989
> Project: Cassandra
> Issue Type: Sub-task
> Reporter: Benedict
> Assignee: Jay Zhuang
> Priority: Minor
> Fix For: 4.x
>
> Attachments: 9989-trunk.txt
>
>
> BTree.Builder could reduce its copying, and exploit toArray more efficiently,
> with some work. It's not very important right now because we don't make as
> much use of its bulk-add methods as we otherwise might, however over time
> this work will become more useful.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
