
SQL in CockroachDB: Mapping Table Data to Key-Value Storage - bdarnell
http://www.cockroachlabs.com/blog/sql-in-cockroachdb-mapping-table-data-to-key-value-storage/
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kodablah
Have been following Cockroach for a bit now, looking forward to it. One of the
things I like about Cassandra's CQL is that it doesn't let you shoot yourself
in the foot. You have to opt-in to doing conditionals that require range
scans, you have to provide the PK (or indexed column) for every query, etc.
Will Cockroach will do similar in forcing the users to select their data in a
certain way that is performant (or at least require opt-out to do full scans)?

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bdarnell
(I work for CockroachDB) This is something that we're definitely interested
in. We haven't decided yet exactly what form it will take, but we plan to
offer some way to ensure that the DB will return an error instead of silently
falling back to an extremely inefficient query plan.

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lobster_johnson
I wonder how this compares to FoundationDB's architecture, which also had an
SQL layer on top of a K/V store, and was reportedly slow at SQL queries.

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bdarnell
(I work for CockroachDB) Our architecture is broadly similar to
FoundationDB's, although in our case the separation between the layers is not
as strict as I believe FoundationDB's was. This will allow us to improve
performance by distributing parts of the SQL processing down to the nodes
where the data lives, instead of doing all the processing on a SQL node that
is distinct from all the data nodes.

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steeve
That's cool, although I'm mostly interested about how they are going to do
distributed JOINs

