cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Tyler Hobbs (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (CASSANDRA-8490) DISTINCT queries with LIMITs or paging are incorrect when partitions are deleted
Date Thu, 08 Jan 2015 19:57:35 GMT

     [ https://issues.apache.org/jira/browse/CASSANDRA-8490?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Tyler Hobbs updated CASSANDRA-8490:
-----------------------------------
    Attachment: 8490-trunk-v2.txt
                8490-2.0-v2.txt

Ah, good point.  The v2 patch makes the suggested change and also updates StorageProxy to
properly handle counting/trimming the rows for this case.

> DISTINCT queries with LIMITs or paging are incorrect when partitions are deleted
> --------------------------------------------------------------------------------
>
>                 Key: CASSANDRA-8490
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-8490
>             Project: Cassandra
>          Issue Type: Bug
>         Environment: Driver version: 2.1.3.
> Cassandra version: 2.0.11/2.1.2.
>            Reporter: Frank Limstrand
>            Assignee: Tyler Hobbs
>             Fix For: 2.0.12, 2.1.3
>
>         Attachments: 8490-2.0-v2.txt, 8490-2.0.txt, 8490-trunk-v2.txt, 8490-trunk.txt
>
>
> Using paging demo code from https://github.com/PatrickCallaghan/datastax-paging-demo
> The code creates and populates a table with 1000 entries and pages through them with
setFetchSize set to 100. If we then delete one entry with 'cqlsh':
> {noformat}
> cqlsh:datastax_paging_demo> delete from datastax_paging_demo.products  where productId
= 'P142'; (The specified productid is number 6 in the resultset.)
> {noformat}
> and run the same query ("Select * from") again we get:
> {noformat}
> [com.datastax.paging.Main.main()] INFO  com.datastax.paging.Main - Paging demo took 0
secs. Total Products : 999
> {noformat}
> which is what we would expect.
> If we then change the "select" statement in dao/ProductDao.java (line 70) from "Select
* from " to "Select DISTINCT productid from " we get this result:
> {noformat}
> [com.datastax.paging.Main.main()] INFO  com.datastax.paging.Main - Paging demo took 0
secs. Total Products : 99
> {noformat}
> So it looks like the tombstone stops the paging behaviour. Is this a bug?
> {noformat}
> DEBUG [Native-Transport-Requests:788] 2014-12-16 10:09:13,431 Message.java (line 319)
Received: QUERY Select DISTINCT productid from datastax_paging_demo.products, v=2
> DEBUG [Native-Transport-Requests:788] 2014-12-16 10:09:13,434 AbstractQueryPager.java
(line 98) Fetched 99 live rows
> DEBUG [Native-Transport-Requests:788] 2014-12-16 10:09:13,434 AbstractQueryPager.java
(line 115) Got result (99) smaller than page size (100), considering pager exhausted
> {noformat}



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Mime
View raw message