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Posted to commits@cassandra.apache.org by "Varun Barala (JIRA)" <ji...@apache.org> on 2016/05/02 16:33:12 UTC

[jira] [Updated] (CASSANDRA-11679) Cassandra Driver returns different number of results depending on fetchsize

     [ https://issues.apache.org/jira/browse/CASSANDRA-11679?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Varun Barala updated CASSANDRA-11679:
-------------------------------------
    Description: 
I'm trying to fetch all distinct keys from a CF using cassandra-driver (2.1.7.1) and I observed some strange behavior :-

The total distinct rows are 498 so If I perform a query get All distinctKeys It returns 503 instead of 498(five keys twice).
But If I define the fetch size in select statement more than 498 then it returns exact 498 rows. 

And If I execute same statement on Dev-center it returns 498 rows (because the default fetch size is 5000). In `cqlsh` it returns 503 rows (because cqlsh uses fetch size=100).

Some Additional and useful information :- 
-------------------------------------------------------
Cassandra-2.1.13  (C)* version
Consistency level: ONE 
local machine(ubuntu 14.04)

Table Schema:-
----------------------

{code:xml}
CREATE TABLE sample (
     pk1 text,
     pk2 text,
    row_id uuid,
    value blob,
    PRIMARY KEY (( pk1,  pk2))
) WITH bloom_filter_fp_chance = 0.01
    AND caching = '{"keys":"ALL", "rows_per_partition":"NONE"}'
    AND comment = ''
    AND compaction = {'class': 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy'}
    AND compression = {'sstable_compression': 'org.apache.cassandra.io.compress.LZ4Compressor'}
    AND dclocal_read_repair_chance = 0.1
    AND default_time_to_live = 0
    AND gc_grace_seconds = 864000
    AND max_index_interval = 2048
    AND memtable_flush_period_in_ms = 0
    AND min_index_interval = 128
    AND read_repair_chance = 0.0
    AND speculative_retry = '99.0PERCENTILE';


{code}

query :-
------------
{code:xml}
SELECT DISTINCT  pk2, pk1 FROM sample LIMIT 2147483647;
{code}

  was:
I'm trying to fetch all distinct keys from a CF using cassandra-driver (2.1.7.1) and I observed some strange behavior :-

The total distinct rows are 498 so If I perform a query get All distinctKeys It return 503 instead of 498(five keys twice).
But If I define the fetch size in select statement more than 498 then it returns exact 498 rows. 

And If I execute same statement on Dev-center it returns 498 rows.

Some Additional and useful information :- 
-------------------------------------------------------
Cassandra-2.1.13  (C)* version
Consistency level: ONE 
local machine(ubuntu 14.04)

Table Schema:-
----------------------

{code:xml}
CREATE TABLE sample (
     pk1 text,
     pk2 text,
    row_id uuid,
    value blob,
    PRIMARY KEY (( pk1,  pk2))
) WITH bloom_filter_fp_chance = 0.01
    AND caching = '{"keys":"ALL", "rows_per_partition":"NONE"}'
    AND comment = ''
    AND compaction = {'class': 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy'}
    AND compression = {'sstable_compression': 'org.apache.cassandra.io.compress.LZ4Compressor'}
    AND dclocal_read_repair_chance = 0.1
    AND default_time_to_live = 0
    AND gc_grace_seconds = 864000
    AND max_index_interval = 2048
    AND memtable_flush_period_in_ms = 0
    AND min_index_interval = 128
    AND read_repair_chance = 0.0
    AND speculative_retry = '99.0PERCENTILE';


{code}

query :-
------------
{code:xml}
SELECT DISTINCT  pk2, pk1 FROM sample LIMIT 2147483647;
{code}


> Cassandra Driver returns different number of results depending on fetchsize
> ---------------------------------------------------------------------------
>
>                 Key: CASSANDRA-11679
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-11679
>             Project: Cassandra
>          Issue Type: Bug
>          Components: CQL
>            Reporter: Varun Barala
>            Assignee: Benjamin Lerer
>
> I'm trying to fetch all distinct keys from a CF using cassandra-driver (2.1.7.1) and I observed some strange behavior :-
> The total distinct rows are 498 so If I perform a query get All distinctKeys It returns 503 instead of 498(five keys twice).
> But If I define the fetch size in select statement more than 498 then it returns exact 498 rows. 
> And If I execute same statement on Dev-center it returns 498 rows (because the default fetch size is 5000). In `cqlsh` it returns 503 rows (because cqlsh uses fetch size=100).
> Some Additional and useful information :- 
> -------------------------------------------------------
> Cassandra-2.1.13  (C)* version
> Consistency level: ONE 
> local machine(ubuntu 14.04)
> Table Schema:-
> ----------------------
> {code:xml}
> CREATE TABLE sample (
>      pk1 text,
>      pk2 text,
>     row_id uuid,
>     value blob,
>     PRIMARY KEY (( pk1,  pk2))
> ) WITH bloom_filter_fp_chance = 0.01
>     AND caching = '{"keys":"ALL", "rows_per_partition":"NONE"}'
>     AND comment = ''
>     AND compaction = {'class': 'org.apache.cassandra.db.compaction.SizeTieredCompactionStrategy'}
>     AND compression = {'sstable_compression': 'org.apache.cassandra.io.compress.LZ4Compressor'}
>     AND dclocal_read_repair_chance = 0.1
>     AND default_time_to_live = 0
>     AND gc_grace_seconds = 864000
>     AND max_index_interval = 2048
>     AND memtable_flush_period_in_ms = 0
>     AND min_index_interval = 128
>     AND read_repair_chance = 0.0
>     AND speculative_retry = '99.0PERCENTILE';
> {code}
> query :-
> ------------
> {code:xml}
> SELECT DISTINCT  pk2, pk1 FROM sample LIMIT 2147483647;
> {code}



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