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From DuyHai Doan <doanduy...@gmail.com>
Subject Re: Delete By Partition Key Implementation
Date Sat, 09 Aug 2014 07:21:23 GMT
Thanks graham for the hints.

I've digged into the source code and found out those 2 classes:

https://github.com/apache/cassandra/blob/trunk/src/java/org/apache/cassandra/db/DeletionInfo.java

https://github.com/apache/cassandra/blob/trunk/src/java/org/apache/cassandra/db/RangeTombstoneList.java

 They are quite self-explanatory.
A deletion of an entire row is a single row tombstone, and yes there are
range tombstones for marking deletion of a range of columns also

On Aug 8, 2014, at 2:17 PM, Kevin Burton <burton@spinn3r.com> wrote:

This is a good question.. I'd love to find out the answer.  Seems like a
tombstone with prefixes for the keys would work well.

Also, can't any key prefixes work in theory?


On Thu, Aug 7, 2014 at 8:33 AM, DuyHai Doan <doanduyhai@gmail.com> wrote:

> Hello all
>
>  Usually, when using DELETE in CQL3 on some fields, C* creates tombstone
> columns for those fields.
>
>  Now if I delete a whole PARTITION (delete from MyTable where
> partitionKey=...), what will C* do ? Will it create as many tombstones as
> there are physical columns on this partition or will it just mark this
> partition as "deleted" (Row Key deletion marker) ?
>
>  On a side note, if I insert a bunch of physical columns in one partition
> with the SAME ttl value, after a while they will appear as expired, would
> C* need to scan the whole partition on disk to see which columns to expire
> or could it see that the whole partition is indeed expired thanks to meta
> data/ Partition key cache kept in memory ?  I was thinking about the
> estimate histograms for TTL but I don't know in detail how it work
>
>  Regards
>
>  Duy Hai  DOAN
>
>


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