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Posted to user@cassandra.apache.org by Baskar Duraikannu <ba...@outlook.com> on 2013/09/03 23:15:48 UTC

RE: List retrieve performance

I don't know of any. I would check the size of LIST. If it is taking long, it could be just that disk read is taking long.  

Date: Sat, 31 Aug 2013 16:35:22 -0300
Subject: List<blob> retrieve performance
From: savio.teles@lupa.inf.ufg.br
To: user@cassandra.apache.org

I have a column family with this conf:

CREATE TABLE geoms (
  geom_key text PRIMARY KEY,
  part_geom list<blob>,
  the_geom text
) WITH
  bloom_filter_fp_chance=0.010000 AND

  caching='KEYS_ONLY' AND
  comment='' AND
  dclocal_read_repair_chance=0.000000 AND
  gc_grace_seconds=864000 AND
  read_repair_chance=0.100000 AND
  replicate_on_write='true' AND

  populate_io_cache_on_flush='false' AND
  compaction={'class': 'SizeTieredCompactionStrategy'} AND
  compression={'sstable_compression': 'SnappyCompressor'};

I run this query "select geom_key, the_geom,  part_geom from geoms limit 1;" in 700ms.

When I run the same query without part_geom attr (select geom_key, the_geom from geoms limit 1;), the query runs in 5 ms. 

Is there a performance problem with a List<blob> attribute?

Thanks in advance

-- 
Atenciosamente,
Sávio S. Teles de Oliveira
voice: +55 62 9136 6996
http://br.linkedin.com/in/savioteles

Mestrando em Ciências da Computação - UFG 
Arquiteto de Software
Laboratory for Ubiquitous and Pervasive Applications (LUPA) - UFG

Re: List retrieve performance

Posted by Sávio Teles <sa...@lupa.inf.ufg.br>.

The list is "null".


2013/9/3 Baskar Duraikannu <ba...@outlook.com>

> I don't know of any. I would check the size of LIST. If it is taking long,
> it could be just that disk read is taking long.
>
> ------------------------------
> Date: Sat, 31 Aug 2013 16:35:22 -0300
> Subject: List<blob> retrieve performance
> From: savio.teles@lupa.inf.ufg.br
> To: user@cassandra.apache.org
>
>
> I have a column family with this conf:
>
> CREATE TABLE geoms (
>   geom_key text PRIMARY KEY,
>   part_geom list<blob>,
>   the_geom text
> ) WITH
>   bloom_filter_fp_chance=0.010000 AND
>   caching='KEYS_ONLY' AND
>   comment='' AND
>   dclocal_read_repair_chance=0.000000 AND
>   gc_grace_seconds=864000 AND
>   read_repair_chance=0.100000 AND
>   replicate_on_write='true' AND
>   populate_io_cache_on_flush='false' AND
>   compaction={'class': 'SizeTieredCompactionStrategy'} AND
>   compression={'sstable_compression': 'SnappyCompressor'};
>
>
> I run this query "*select geom_key, the_geom, part_geom from geoms limit
> 1;*" in 700ms.
>
> When I run the same query without part_geom attr (*select geom_key,
> the_geom from geoms limit 1;)*, the query runs in 5 ms.
>
> *Is there a performance problem with a List<blob> attribute?
>
> *
> *Thanks in advance
> *
>
> --
> Atenciosamente,
> Sávio S. Teles de Oliveira
> voice: +55 62 9136 6996
> http://br.linkedin.com/in/savioteles
>  Mestrando em Ciências da Computação - UFG
> Arquiteto de Software
> Laboratory for Ubiquitous and Pervasive Applications (LUPA) - UFG
>



-- 
Atenciosamente,
Sávio S. Teles de Oliveira
voice: +55 62 9136 6996
http://br.linkedin.com/in/savioteles
Mestrando em Ciências da Computação - UFG
Arquiteto de Software
Laboratory for Ubiquitous and Pervasive Applications (LUPA) - UFG