Trying to parse and export an sstable at a higher, CQL level with the current codebase is going to be pretty tough. Handling static columns, collections (multi-cell columns), and the four minor variants of sstable formats (sparse vs dense, composite vs simple) is not easy. If you want to handle things at a CQL level, you should probably go through the normal read path.
With that said, CASSANDRA-8099 will substantially change the format of sstables to more closely match CQL, making this more feasible. On Tue, May 26, 2015 at 8:49 AM, Malcolm Matalka <malc...@spotify.com> wrote: > Thanks Tyler, > > The problem with sstable2json is that it does not support the CQL > types as far as I can see and there isn't any indication as to modify > it to do that. It seems like the CQL things are a layer above the > SSTable. > > 2015-05-26 15:44 GMT+02:00 Tyler Hobbs <ty...@datastax.com>: > > I would start by looking at sstable2json. It may be simplest for you to > > run sstable2json and then process the resulting json. If that's not > > adequate, modifying the sstable2json code is probably your best bet. > > > > On Mon, May 25, 2015 at 11:12 AM, Malcolm Matalka <malc...@spotify.com> > > wrote: > > > >> Hello, > >> > >> For efficiency reasons I am trying to parse the raw SSTable files in > >> order to transform them into another format. I understand this is > >> like poking a sleeping beast and there aren't many guarantees around > >> this but I'm asking if anyone has any pointers to make this possible? > >> In a search I have stumbled upon FullContact's SSTable parser, but it > >> does not parse the complicated data structures that CQL supports. In > >> attempting to reverse engineer how Cassandra handles the actual data > >> there are a few cases that are unclear and I'm concerned that my > >> attempts to interpret them will result in a fragile result. > >> > >> Are there any suggestions? Existing libraries? Tips on how Cassandra > >> parses the data itself? Pointers into the code to read? SSTable > >> design doc? > >> > >> Thanks, > >> /Malcolm > >> > > > > > > > > -- > > Tyler Hobbs > > DataStax <http://datastax.com/> > -- Tyler Hobbs DataStax <http://datastax.com/>
