You mean if you use the same UDF in multiple places in the Pig Latin script? UDFContext allows you to pass a signature when using it so you can distinguish between different invocations of the same UDF.
Alan. On Feb 23, 2012, at 2:08 PM, Jonathan Coveney wrote: > Alan, with the work that was done to get Schema information on the backend, > is UDFContext now safe to use? It used to create issues if you used the UDF > in multiple places because it was static. > > 2012/2/23 Alan Gates <[email protected]> > >> You can use UDFContext to pass information from the frontend to the >> backend. That is, if you want the UDF to generate some sequence number >> during the parse/planning stage and pass that to itself for use during >> execution, you can do that. >> >> You cannot pass information between invocations of a UDF once you are >> running in the job. MapReduce does not provide any method of execution >> between tasks beyond the data. Doing so would require synchronization and >> a number of other features MapReduce doesn't provide. >> >> Alan. >> >> On Feb 22, 2012, at 8:57 PM, Shibu Thomas wrote: >> >>> Hi, >>> >>> Is there any mechanism of retaining state between PIG UDF invocations? >>> >>> Thanks >>> >>> Shibu Thomas >>> MSCIS-IS >>> Office : +91 (40) 669 32660 >>> Mobile: +91 95811 51116 >>> >> >>
