[ https://issues.apache.org/jira/browse/CASSANDRA-3798?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Sylvain Lebresne updated CASSANDRA-3798: ---------------------------------------- Attachment: 3798.patch Patch attached against 1.1 (I don't really see a reason to risk back-porting to 1.0). > get_count paging often asks for a page uselessly > ------------------------------------------------ > > Key: CASSANDRA-3798 > URL: https://issues.apache.org/jira/browse/CASSANDRA-3798 > Project: Cassandra > Issue Type: Improvement > Affects Versions: 1.0.0 > Reporter: Sylvain Lebresne > Assignee: Sylvain Lebresne > Priority: Minor > Fix For: 1.1 > > Attachments: 3798.patch > > > Current get_count paging stopping condition is: > {noformat} > if ((requestedCount == 0) || ((columns.size() == 1) && > (lastName.equals(predicate.slice_range.start)))) > { > break; > } > {noformat} > On a "count how many columns this row has" query (arguably the main reason > why you'd use get_count), requestedCount will never be 0, and so we'll stop > whenever a page has only returned the last column of the preceding page. > While this isn't wrong, we could stop as soon as a page returns less element > than requested and avoid querying that last 1 column page. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira