Hi Tupshin, Thanks for your help; I appreciate it.
Could I do something like the following? Given the same table you started with: x | y | t | z ---+---+---+---- a | 1 | 2 | 10 a | 2 | 2 | 20 I'd like to write a compare-and-set that does something like: "If there is a row with (x,y,t,z) = (a,1,2,10), then update/insert a row with (x,y,t,z) = (a,3,4,5) and update/insert a row with (x,y,t,z) = (a,4,5,6)." I don't see how I could do this with what you outlined above---just curious. It seems like what I describe above under the hood would be a compare-and-(batch)-set on a single wide row, so it maybe is possible with the Thrift API (I have to check). Thanks again! Best regards, Clint On Sat, Feb 22, 2014 at 11:38 AM, Tupshin Harper <tups...@tupshin.com> wrote: > #5633 was actually closed because the static columns feature > (https://issues.apache.org/jira/browse/CASSANDRA-6561) which has been > checked in to the 2.0 branch but is not yet part of a release (it will be in > 2.0.6). > > That feature will let you update multiple rows within a single partition by > doing a CAS write based on a static column shared by all rows within the > partition. > > Example extracted from the ticket: > CREATE TABLE foo ( > x text, > y bigint, > t bigint static, > z bigint, > PRIMARY KEY (x, y) ); > > insert into foo (x,y,t, z) values ('a', 1, 1, 10); > insert into foo (x,y,t, z) values ('a', 2, 2, 20); > > select * from foo; > > x | y | t | z > ---+---+---+---- > a | 1 | 2 | 10 > a | 2 | 2 | 20 > (Note that both values of "t" are 2 because it is static) > > > begin batch update foo set z = 1 where x = 'a' and y = 1; update foo set z > = 2 where x = 'a' and y = 2 if t = 4; apply batch; > > [applied] | x | y | t > -----------+---+------+--- > False | a | null | 2 > > (Both updates failed to apply because there was an unmet conditional on one > of them) > > select * from foo; > > x | y | t | z > ---+---+---+---- > a | 1 | 2 | 10 > a | 2 | 2 | 20 > > > begin batch update foo set z = 1 where x = 'a' and y = 1; update foo set z = > 2 where x = 'a' and y = 2 if t = 2; apply batch; > > [applied] > ----------- > True > > (both updates succeeded because the check on t succeeded) > > select * from foo; > x | y | t | z > ---+---+---+--- > a | 1 | 2 | 1 > a | 2 | 2 | 2 > > Hope this helps. > > -Tupshin > > > > On Fri, Feb 21, 2014 at 6:05 PM, DuyHai Doan <doanduy...@gmail.com> wrote: >> >> Hello Clint >> >> The Resolution status of the JIRA is set to "Later", probably the >> implementation is not done yet. The JIRA was opened to discuss about impl >> strategy but nothing has been coded so far I guess. >> >> >> >> On Sat, Feb 22, 2014 at 12:02 AM, Clint Kelly <clint.ke...@gmail.com> >> wrote: >>> >>> Folks, >>> >>> Does anyone know how I can modify multiple rows at once in a >>> lightweight transaction in CQL3? >>> >>> I saw the following ticket: >>> >>> https://issues.apache.org/jira/browse/CASSANDRA-5633 >>> >>> but it was not obvious to me from the comments how (or whether) this >>> got resolved. I also couldn't find anything in the DataStax >>> documentation about how to perform these operations. >>> >>> I'm in particular interested in how to perform a compare-and-set >>> operation that modifies multiple rows (with the same partition key) >>> using the DataStax Java driver. >>> >>> Thanks! >>> >>> Best regards, >>> Clint >> >> >
