skip is going to be a performance penalty, since couch need to seek over all skipped rows, IIRC. but for smaller skip-values this approach should work
On 28.06.2010, at 15:36, Mike Keen wrote: > In the application requesting the view, generate a random skip parameter, and > set the limit parameter to 3. This will allow you to grab a random set of > results from Couch. More info on these parameters is here: > > http://wiki.apache.org/couchdb/HTTP_view_API#Querying_Options > > Just make sure skip is never greater than the number of total results - 3. > > Mike > > On Jun 28, 2010, at 9:29 AM, <[email protected]> > <[email protected]> wrote: > >> Hello couchers, >> >> how would you do to select a random subset of a view result (a simple view >> with map only). >> >> Example (I don't write the full view response array for clarity) >> >> When called normally, my view returns : >> >> { >> ... >> rows: [ >> {id: aa1}, >> {id: aa2}, >> {id: aa3}, >> {id: aa4}, >> {id: aa5}, >> {id: aa6}, >> {id: aa7}, >> {id: aa8}, >> {id: aa9} >> ] >> } >> >> And I want only three of those rows, randomly chosen. So I launch the magic >> "get three random rows" feature, and it gives me : >> >> { >> ... >> rows: [ >> {id: aa5}, >> {id: aa3}, >> {id: aa6} >> ] >> } >> >> The second time I launch the same magic "get three random rows" I got: >> { >> ... >> rows: [ >> {id: aa7}, >> {id: aa1}, >> {id: aa5} >> ] >> } >> >> Thanks for your advices >> >> Mickael >
