Trying to understand why tombstone is being read

[Adam Patacchiola <ad...@2fours.com>]

I have a table defined in cql like this:

CREATE TABLE chatmessages (
  username    varchar,
  spotname    varchar,
  id          varint,
  iv          varchar,
  fromuser        varchar,
  fromversion varchar,
  touser          varchar,
  toversion   varchar,
  datetime    timestamp,
  data        varchar,
  mimetype    varchar,
  datasize    int,
  shareable   boolean,
  PRIMARY KEY (username, spotname, id)
)

That I insert messages into. Occasionally "rows" are deleted. My question
is why, when I query for a "row" using a select query specific to only that
"row" which contains cells that have never been deleted such as:

  select * from chatmessages where username='adam' and
spotname='adam:cherie' and id =1860;

Am I seeing in the cqlsh trace that 1 tombstoned cell has been read:

"Read 1 live and 1 tombstoned cells"

Thanks for any way you can help increase my understanding of what's going
on here.

Adam

Re: Trying to understand why tombstone is being read

[Machiel Groeneveld <ma...@gmail.com>]

We had a similar question, a column inserted with a null value also results in a tombstone.

Also see the (closed) issue about this:
https://issues.apache.org/jira/browse/CASSANDRA-6674

On 13 Feb 2014, at 16:35, Adam Patacchiola <ad...@2fours.com> wrote:

> I have a table defined in cql like this:
> 
> CREATE TABLE chatmessages (
>   username    varchar,
>   spotname    varchar,
>   id          varint,
>   iv          varchar,
>   fromuser        varchar,
>   fromversion varchar,
>   touser          varchar,
>   toversion   varchar,
>   datetime    timestamp,
>   data        varchar,
>   mimetype    varchar,
>   datasize    int,
>   shareable   boolean,
>   PRIMARY KEY (username, spotname, id)
> )
> 
> That I insert messages into. Occasionally "rows" are deleted. My question is why, when I query for a "row" using a select query specific to only that "row" which contains cells that have never been deleted such as:
> 
>   select * from chatmessages where username='adam' and spotname='adam:cherie' and id =1860;
> 
> Am I seeing in the cqlsh trace that 1 tombstoned cell has been read:
> 
> "Read 1 live and 1 tombstoned cells"
> 
> Thanks for any way you can help increase my understanding of what's going on here.
> 
> Adam