mentat/db/README.md

This sub-crate implements the SQLite database layer: installing,
managing, and migrating forward the SQL schema underlying the datom
store.
Start installing SQL schema. (#171) r=rnewman * Start installing the SQLite store and bootstrapping the datom store. * Review comment: Decomplect V2_IDENTS. * Review comment: Decomplect V2_PARTS. * Review comment: Pre: Expose Clojure's merge on Value instances. * Review comment: Decomplect V2_SYMBOLIC_SCHEMA. * Review comment: Decomplect V1_STATEMENTS. * Review comment: Prefer ? to try!. * Review comment: Fix typos; format; add TODOs. * Review comment: Assert that Mentat `Schema` is valid upon creation. * Review comment: Improve conversion to and from SQL values. This patch factors the fundamental SQL conversion maps between (rusqlite::Value, value_type_tag) and (edn::Value, ValueType) through a new Mentat TypedValue. (A future patch might rename this fundamental type mentat::Value.) To make certain conversion functions infallible, I removed placeholders for :db.type/{instant,uuid,uri}. (We could panic instead, but there's no need to do that right now.) * Review comment: Always uses bundled SQLite in rusqlite. This avoids (runtime) failures in Travis CI due to old SQLite versions. See https://github.com/jgallagher/rusqlite/commit/432966ac77e3cb27c4cd67d073788498336988a2. * Review comment: Move semantics in `from_sql_value_pair`. * Review comment: DB_EXCISE_BEFORE_T instead of ...BEFORET (no underscore). * Review comment: Move overview notes to the Wiki. 2017-01-26 00:13:56 +00:00			`This sub-crate implements the SQLite database layer: installing,`
			`managing, and migrating forward the SQL schema underlying the datom`
			`store.`