mentat/query-translator
Richard Newman 95b9c7f7f5
Atomic multi-tx (#489). r=emily,nalexander
* Pre: rename begin_transaction to begin_tx_application.

* Take an EXCLUSIVE transaction when bootstrapping, and an IMMEDIATE transaction when writing.

This avoids the remote possibility of another write sneaking in the door
while we're preparing to write, avoids us needing to upgrade locks, etc.

  After a BEGIN IMMEDIATE, no other database connection will be able to write
  to the database or do a BEGIN IMMEDIATE or BEGIN EXCLUSIVE. Other processes
  can continue to read from the database, however.

  An exclusive transaction causes EXCLUSIVE locks to be acquired on all
  databases. After a BEGIN EXCLUSIVE, no other database connection except for
  read_uncommitted connections will be able to read the database and no other
  connection without exception will be able to write the database until the
  transaction is complete.

* Hacky implementation of atomic multi-tx.

* Hold the last report, returning the InProgress from each operation.

* Rewrite transact in terms of InProgress.

* Test rollback.

* Remove unused imports.

* Don't use Rc for transaction reports.

* Pre: break out USER0 as a part boundary constant.

* Export TX0 and USER0 from mentat_db. This is for testing.

* Review comments: commenting.

* Test tempid allocation and rollback.
2017-12-05 07:58:24 -08:00
..
src Atomic multi-tx (#489). r=emily,nalexander 2017-12-05 07:58:24 -08:00
tests Partial work from simple aggregates work (#497) r=nalexander 2017-11-30 15:02:07 -08:00
Cargo.toml Partial work from simple aggregates work (#497) r=nalexander 2017-11-30 15:02:07 -08:00
README.md Begin serializing queries to SQL. r=nalexander 2017-02-17 17:54:07 -08:00

This crate turns an algebrized Datalog query into a domain-specific representation of a SQL query, and then uses mentat_sql to turn that into a SQL string to be executed.

This subsumes both planning and query construction, because in Mentat the SQL query is effectively a query plan.