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From Mike Carter <jaloos...@gmail.com>
Subject Re: How to perform Range Queries in Cassandra
Date Fri, 04 Jul 2014 14:14:37 GMT
Does it mean, that Cassandra is not useful for any count queries on more
than one columns?


2014-06-24 15:21 GMT+02:00 Jeremy Jongsma <jeremy@barchart.com>:

> You'd be better off using external indexing (ElasticSearch or Solr),
> Cassandra isn't really designed for this sort of querying.
> On Jun 24, 2014 3:09 AM, "Mike Carter" <jalooser2@gmail.com> wrote:
>
>> Hello!
>>
>>
>> I'm a beginner in C* and I'm quite struggling with it.
>>
>> I’d like to measure the performance of some Cassandra-Range-Queries. The
>> idea is to execute multidimensional range-queries on Cassandra. E.g. there
>> is a given table of 1million rows with 10 columns and I like to execute
>> some queries like “select count(*) from testable where d=1 and v1<10 and v2
>> >20 and v3 <45 and v4>70 … allow filtering”.  This kind of queries is
very
>> slow in C* and soon the tables are bigger, I get a read-timeout probably
>> caused by long scan operations.
>>
>> In further tests I like to extend the dimensions to more than 200
>> hundreds and the rows to 100millions, but actually I can’t handle this
>> small table. Should reorganize the data or is it impossible to perform such
>> high multi-dimensional queries on Cassandra?
>>
>>
>>
>>
>>
>> The setup:
>>
>> Cassandra is installed on a single node with 2 TB disk space and 180GB
>> Ram.
>>
>> Connected to Test Cluster at localhost:9160.
>>
>> [cqlsh 4.1.1 | Cassandra 2.0.7 | CQL spec 3.1.1 | Thrift protocol 19.39.0]
>>
>>
>>
>> Keyspace:
>>
>> CREATE KEYSPACE test WITH replication = {
>>
>>   'class': 'SimpleStrategy',
>>
>>   'replication_factor': '1'
>>
>> };
>>
>>
>>
>>
>>
>> Table:
>>
>> CREATE TABLE testc21 (
>>
>>   key int,
>>
>>   d int,
>>
>>   v1 int,
>>
>>   v10 int,
>>
>>   v2 int,
>>
>>   v3 int,
>>
>>   v4 int,
>>
>>   v5 int,
>>
>>   v6 int,
>>
>>   v7 int,
>>
>>   v8 int,
>>
>>   v9 int,
>>
>>   PRIMARY KEY (key)
>>
>> ) WITH
>>
>>   bloom_filter_fp_chance=0.010000 AND
>>
>>   caching='ROWS_ONLY' AND
>>
>>   comment='' AND
>>
>>   dclocal_read_repair_chance=0.000000 AND
>>
>>   gc_grace_seconds=864000 AND
>>
>>   index_interval=128 AND
>>
>>   read_repair_chance=0.100000 AND
>>
>>   replicate_on_write='true' AND
>>
>>   populate_io_cache_on_flush='false' AND
>>
>>   default_time_to_live=0 AND
>>
>>   speculative_retry='99.0PERCENTILE' AND
>>
>>   memtable_flush_period_in_ms=0 AND
>>
>>   compaction={'class': 'SizeTieredCompactionStrategy'} AND
>>
>>   compression={'sstable_compression': 'LZ4Compressor'};
>>
>>
>>
>> CREATE INDEX testc21_d_idx ON testc21 (d);
>>
>>
>>
>>  select * from testc21 limit 10;
>>
>> key    | d | v1 | v10 | v2 | v3 | v4  | v5 | v6 | v7 | v8 | v9
>>
>> --------+---+----+-----+----+----+-----+----+----+----+----+-----
>>
>>  302602 | 1 | 56 |  55 | 26 | 45 |  67 | 75 | 25 | 50 | 26 |  54
>>
>>  531141 | 1 | 90 |  77 | 86 | 42 |  76 | 91 | 47 | 31 | 77 |  27
>>
>>  693077 | 1 | 67 |  71 | 14 | 59 | 100 | 90 | 11 | 15 |  6 |  19
>>
>>    4317 | 1 | 70 |  77 | 44 | 77 |  41 | 68 | 33 |  0 | 99 |  14
>>
>>  927961 | 1 | 15 |  97 | 95 | 80 |  35 | 36 | 45 |  8 | 11 | 100
>>
>>  313395 | 1 | 68 |  62 | 56 | 85 |  14 | 96 | 43 |  6 | 32 |   7
>>
>>  368168 | 1 |  3 |  63 | 55 | 32 |  18 | 95 | 67 | 78 | 83 |  52
>>
>>  671830 | 1 | 14 |  29 | 28 | 17 |  42 | 42 |  4 |  6 | 61 |  93
>>
>>   62693 | 1 | 26 |  48 | 15 | 22 |  73 | 94 | 86 |  4 | 66 |  63
>>
>>  488360 | 1 |  8 |  57 | 86 | 31 |  51 |  9 | 40 | 52 | 91 |  45
>>
>> Mike
>>
>

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