IMHO, having many tombstones can slow down reads and writes in the
following cases :
- For reads, it is slow if the requested slice contains many tombstones
- For writes, it is is slower if the row in the memtable contains many
tombstones. It's because, if the IntervalTree contains N intervals,
As documented at http://cassandra.apache.org/doc/cql3/CQL.html#collections,
the lists have 3 operations that require a read before a write (and should
thus be avoided in performance sensitive code), namely setting and deleting
by index, and removing by value. Outside of that, collections involves n
the thing I was doing was definitely triggering the range tombstone issue,
this is what I was doing:
UPDATE clocks SET clock = ? WHERE shard = ?
in this table:
CREATE TABLE clocks (shard INT PRIMARY KEY, clock MAP)
however, from the stack overflow posts it sounds like they aren't
necess
Can you provide details of the mutation statements you are running ? The Stack
Overflow posts don't seem to include them.
Cheers
-
Aaron Morton
Freelance Cassandra Consultant
New Zealand
@aaronmorton
http://www.thelastpickle.com
On 27/06/2013, at 5:58 AM, Theo Hultberg wrote:
do I understand it correctly if I think that collection modifications are
done by reading the collection, writing a range tombstone that would cover
the collection and then re-writing the whole collection again? or is it
just the modified parts of the collection that are covered by the range
tombst
Hi,
I'm pretty sure that it's related to this ticket :
https://issues.apache.org/jira/browse/CASSANDRA-5677
I'd be happy if someone tests this patch.
It should apply easily on 1.2.5 & 1.2.6
After applying the patch, by default, the current implementation is still
used, but modify your cassandra.
Hi,
I've seen a couple of people on Stack Overflow having problems with
performance when they have maps that they continuously update, and in
hindsight I think I might have run into the same problem myself (but I
didn't suspect it as the reason and designed differently and by accident
didn't use m
wer your initial question, the binary format used by map
> (that you will have to decode yourself) is described in
> https://git-wip-us.apache.org/repos/asf?p=cassandra.git;a=blob;f=doc/native_protocol.spec(Section
> 6).
>
> --
> Sylvain
>
>
> On Mon, Mar 25, 2013 at 2:30
o!
>
> I got stuck when trying to query CQL3 collections from Java.
> I'm using Cassandra 1.2.3 with CQL3. I created a column family to store a
> property graph's edges with the following command:
>
> CREATE TABLE vertices (
> id text PRIMARY KEY,
> properties
Hello!
I got stuck when trying to query CQL3 collections from Java.
I'm using Cassandra 1.2.3 with CQL3. I created a column family to store a
property graph's edges with the following command:
CREATE TABLE vertices (
id text PRIMARY KEY,
properties map
)
I can access the data from
I wrote an answer on the blog post
(http://www.datastax.com/dev/blog/cql3_collections#comment-127093).
--
Sylvain
On Thu, Sep 20, 2012 at 7:13 AM, Roshni Rajagopal
wrote:
> Hi,
>
> CQL3, has collections support as described in this link
> http://www.datastax.com/dev/blog/cql3_collections
>
> So
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