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From Baskar Duraikannu <baskar.duraika...@outlook.com>
Subject RE: List<blob> retrieve performance
Date Tue, 03 Sep 2013 21:15:48 GMT
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
 		 	   		  
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