Unfortunately there is no option to vote for a "resolved" ticket, but if you can propose a better syntax that people agree on, you could probably get some fresh traction on it.
-Tupshin On Feb 25, 2014 7:20 PM, "Clint Kelly" <clint.ke...@gmail.com> wrote: > Hi Tupshin, > > Thanks for your help! Unfortunately in my case, I will need to do a > compare and set in which the compare is against a value in a dynamic column. > > In general, I need to be able to do the following: > > - Check whether a given value exists in a dynamic column > - If so, perform some number of insertions / deletions for dynamic > columns in the same row (i.e., with the same partition key as the dynamic > column used for the compare) > > I think you are correct that I need > https://issues.apache.org/jira/browse/CASSANDRA-5633 to be implemented. > Is there any way to vote for that to get picked up again? :) > > Best regards, > Clint > > > > > > On Mon, Feb 24, 2014 at 2:32 PM, Tupshin Harper <tups...@tupshin.com>wrote: > >> Hi Clint, >> >> That does appear to be an omission in CQL3. It would be possible to >> simulate it by doing >> BEGIN BATCH >> UPDATE foo SET z = 10 WHERE x = 'a' AND y = 1 IF t= 2 AND z=10; >> UPDATE foo SET t = 5,z=6 where x = 'a' AND y = 4 >> APPLY BATCH; >> >> However, this does a redundant write to the first row if the condition >> holds, and I certainly wouldn't recommend doing that routinely. >> >> Alternatively, depending on your needs, you might be able to use a static >> column (coming with 2.0.6) as your conditional flag, as that column is >> shared by all rows in the partition. >> >> -Tupshin >> >> >> >> On Mon, Feb 24, 2014 at 3:57 PM, Clint Kelly <clint.ke...@gmail.com>wrote: >> >>> 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 >>> >> >>> >> >>> > >>> >> >> >
