cassandra-commits mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Alex Petrov (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (CASSANDRA-13379) SASI index returns duplicate rows
Date Mon, 27 Mar 2017 08:45:41 GMT

    [ https://issues.apache.org/jira/browse/CASSANDRA-13379?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15942849#comment-15942849
] 

Alex Petrov commented on CASSANDRA-13379:
-----------------------------------------

Thank you for reporting. I suspect this is a paging issue.

Could you please check if the duplicates are on the page boundaries? For that you could run
{{paging 10}} in cqlsh and then try running your request again: 

{code}
select * from bulks_recipients where bulk_id_idx = fedd95ec-2cc8-4040-8619-baf69647700b;
{code}

Then skipping through the pages. If the last entry of each page is the same as the first entry
of the next page, that'd be it.

Thank you for assistance. 

> SASI index returns duplicate rows
> ---------------------------------
>
>                 Key: CASSANDRA-13379
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-13379
>             Project: Cassandra
>          Issue Type: Bug
>          Components: sasi
>            Reporter: Igor Novgorodov
>
> {code}
> CREATE TABLE bulks_recipients (
>     bulk_id uuid,
>     recipient text,
>     bulk_id_idx uuid,
>     PRIMARY KEY ((bulk_id, recipient))
> )
> {code}
> *bulk_id_idx* is just a copy of *bulk_id* because SASI does not work on partition key
component at all for some reason.
> {code}
> CREATE CUSTOM INDEX bulks_recipients_bulk_id ON bulks_recipients (bulk_id_idx) USING
'org.apache.cassandra.index.sasi.SASIIndex';
> {code}
> Then i insert 1 million rows with the same *bulk_id* and different *recipient*. Then

> {code}
> > select count(*) from bulks_recipients ;
>  count
> ---------
>  1000000
> (1 rows)
> {code}
> Ok, it's fine here. Now let's query by SASI:
> {code}
> > select count(*) from bulks_recipients where bulk_id_idx = fedd95ec-2cc8-4040-8619-baf69647700b;
>  count
> ---------
>  1010101
> (1 rows)
> {code}
> Hmm, very strange count - 10101 extra rows.
> Ok, i've dumped the query result into a text file:
> {code}
> # cat sasi.txt | wc -l
> 1000200
> {code}
> Here we have 200 extra rows for some reason.
> Let's check if these are duplicates:
> {code}
> # cat sasi.txt | sort | uniq | wc -l
> 1000000
> {code}
> Yep, looks like.
> Recreating index does not help. If i issue the very same query (against partition key
*bulk_id*, not *bulk_id_idx*) - i get correct results.



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)

Mime
View raw message