I believe Plasma only has Python bindings. FWIW it has not seen active development in quite a while.
Neal On Mon, Jan 4, 2021 at 8:58 AM Chris Nuernberger <[email protected]> wrote: > Yes that makes sense. I guess you also need something to broker shared > memory filenames/ids. The database isn't in-memory, however, although I > know what you mean. One huge advantage of mmap is you can have much larger > than memory storage act like in-memory storage; so the plasma store can be > roughly the size of your disk and larger your ram but your program, unless > it attempts to verbatim copy a column wouldn't know any better. > > Numerical larger-than-memory-but-in-memory redis indeed; that is an > interesting way to think of it. > > On Mon, Jan 4, 2021 at 9:45 AM Thomas Browne <[email protected]> wrote: > >> Interesting and agreed. I guess this a big advantage of the "on the wire" >> unserialised format - just read it in and it's already native. I'll go this >> way possibly. >> >> However I also note the beginnings of more advanced functionality in the >> Plasma store, for example, notification API on buffer seal (ie when >> something changes, all clients can be notified). >> >> >> https://arrow.apache.org/docs/python/generated/pyarrow.plasma.PlasmaClient.html#pyarrow.plasma.PlasmaClient.subscribe >> >> I'm assuming the plasma store will add functionality over time, and if >> this is the case, having all client libraries implement it means I can >> almost have a redis-like column-store specialising in numerical computation >> (which would be awesome), and for which i don't need to write my own >> functionality for each client library. >> >> A numerical in-memory database, if you will. >> On 04/01/2021 15:55, Chris Nuernberger wrote: >> >> Julia, Python, and R all have some support for mmap operations. >> >> On Mon, Jan 4, 2021 at 8:55 AM Chris Nuernberger <[email protected]> >> wrote: >> >>> Could simply saving the arrow file in streaming mode to shared memory >>> and then mmap-ing the result in each language solve your problem ? Plasma >>> seems to me to be a layer on top of basic mmap operations; as long as you >>> have shared memory and mmap then you can have multiple processes talking to >>> the same logical block of memory. >>> >>> On Mon, Jan 4, 2021 at 8:27 AM Thomas Browne <[email protected]> wrote: >>> >>>> I am hoping to use the Apache Arrow project for cross-language >>>> numerical >>>> computation, and for that the shared-memory idea is very powerful. Am I >>>> correct that the Plasma Store is the enabling technology for this, >>>> especially for soft real-time computation (ie not moving to parquet or >>>> any file-based sharing system)? >>>> >>>> Is that the case? And if so, then I'm wondering which client libraries, >>>> other than Python (and I assume C[++]), implement the Plasma Store. >>>> This >>>> table doesn't feature a row for Plasma: >>>> >>>> https://arrow.apache.org/docs/status.html >>>> >>>> and I can't seem to find any reference to the Plasma store in the >>>> Julia, >>>> R, or Javascript libraries. >>>> >>>> https://arrow.apache.org/docs/r/ >>>> >>>> https://arrow.apache.org/docs/js/ >>>> >>>> https://arrow.juliadata.org/stable/ >>>> >>>> >>>> Thank you, >>>> >>>> Thomas >>>> >>>> >>>>
