Mounting
Mounting is the ability to add datasets and remote databases to a sgr
engine
without having to actually download or clone them. You can then query these
datasets with any PostgreSQL client, with the sgr
engine transparently
rewriting and forwarding queries to the upstream data source.
Besides querying these "live" sources directly, you can also reference them in
Splitfiles or snapshot them with
sgr import
, creating a new
Splitgraph image.
Mounting is powered by PostgreSQL
foreign data wrappers
and we added some scaffolding to them to make it easy to create foreign tables
from the sgr
client. sgr
also ships with a few open-source foreign data
wrappers, letting you query other PostgreSQL/MySQL databases, MongoDB
collections or even government open data directly
through sgr
.
Finally, it's straightforward to
write your own foreign data wrapper
with Multicorn or integrate
existing ones with
sgr
.