mentat/query-algebrizer
Nick Alexander 3cc8b4fd24 Pre: Prefer [(pred ...)] to [[pred ...]] syntax.
This is a style choice.  We supported both, perhaps for Datomic
compliance, but it's not the standard we use in our code base.  In
addition, it doesn't read like lisp (which is what EDN is copying),
since [] is not function application in most lisps.

It's also a convenience: I don't want to parse brackets that have to
agree with `rust-peg`.  It's not hard but it's also not worth doing.
2018-06-04 14:52:51 -07:00
..
src Pre: Prefer [(pred ...)] to [[pred ...]] syntax. 2018-06-04 14:52:51 -07:00
tests Include namespace-separating solidus in NamespaceableName; improve type handling around ground (#713) r=nalexander 2018-05-29 16:45:53 +02:00
Cargo.toml Partial work from simple aggregates work (#497) r=nalexander 2017-11-30 15:02:07 -08:00
README.md Partly flesh out query algebrizer. (#243) r=nalexander 2017-02-15 16:10:59 -08:00

This crate turns a parsed query, as defined by the query crate and produced by the query-parser crate, into an algebrized tree, also called a query processor tree.

This is something of a wooly definition: a query algebrizer in a traditional relational database is the component that combines the schema — including column type constraints — with the query, resolving names and that sort of thing. Much of that work is unnecessary in our model; for example, we don't need to resolve column aliases, deal with table names, or that sort of thing. But the similarity is strong enough to give us the name of this crate.

The result of this process is traditionally handed to the query optimizer to yield an execution plan. In our case the execution plan is deterministically derived from the algebrized tree, and the real optimization (such as it is) takes place within the underlying SQLite database.