Hello everyone,
I’m learning to use hsds and I was wondering if with the different APIs, especially h5pyd, it would be possible to make complex queries similar to what we can do with pytables. I’m interested in any tutorials and links to hsds query performance compared to sql type databases.
Thanks for your interest in HSDS!
Yes, HSDS supports a dataset query operator which works much like the pytables method. Take a look at how the read_where method is used in https://github.com/HDFGroup/h5pyd/blob/master/test/hl/test_table.py. Is that the type of thing that you are looking for?
Re performance - I think in general it won’t be as fast as a dedicated SQL database, in part because HSDS doesn’t support indexing. On the other hand, HSDS does uses parallelism (one process per DN container) to enhance performance of the queries and you have one less thing (i.e. setting up a SQL server in addition to HSDS) to deal with.
If you have a chance to do some performance comparisons between HSDS and a SQL database, I’d be interested to see how it went.