[ https://issues.apache.org/jira/browse/CASSANDRA-4835?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Jonathan Ellis reopened CASSANDRA-4835: --------------------------------------- Assignee: Sylvain Lebresne Sylvain points out that we actually do expect update order to be preserved *within the same row*. Reopening. > Appending/Prepending items to list using BATCH > ---------------------------------------------- > > Key: CASSANDRA-4835 > URL: https://issues.apache.org/jira/browse/CASSANDRA-4835 > Project: Cassandra > Issue Type: Bug > Affects Versions: 1.2.0 beta 1 > Reporter: Krzysztof Cieslinski > Assignee: Sylvain Lebresne > Priority: Minor > > As I know, there is no any guarantee that commands that are inside BATCH > block will execute in same order, as they are stored in the BATCH block. > But... > I have made two tests: > First appends some items to the empty list, and the second one, prepends > items, also to the empty list. Both of them are using UPDATE commands stored > in the BATCH block. > Results of those tests are as follow: > First: > When appending new items to list, USING commands are executed in the > same order as they are stored i BATCH. > Second: > When prepending new items to list, USING commands are executed in > random order. > So, in other words below code: > {code:xml} > BEGIN BATCH > UPDATE... list_name = list_name + [ '1' ] > UPDATE... list_name = list_name + [ '2' ] > UPDATE... list_name = list_name + [ '3' ] > APPLY BATCH;{code} > always results in [ '1', '2', '3' ], > but this code: > {code:xml} > BEGIN BATCH > UPDATE... list_name = [ '1' ] + list_name > UPDATE... list_name = [ '2' ] + list_name > UPDATE... list_name = [ '3' ] + list_name > APPLY BATCH;{code} > results in randomly ordered list, like [ '2', '1', '3' ] (expected result > is [ '3', '2', '1' ]) > So somehow, when appending items to list, commands from BATCH are executed in > order as they are stored, but when prepending, the order is random. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira