2017-10-08 (v0.3)

• replaced overuse of undefined with Proxy in Tupleable and Atomable typeclasses
• allow notifications to return query results from before and after the commit which triggered the notification
• alert users in tutd console before a transaction graph expression is evaluated which would throw out their changes
• drastically-improved CSV import/export now supports all possible types except RelationAtom
• fix serious file handle leaks when using on-disk persistence
• fix case where invalid number of arguments to ConstructedAtom did not result in an error
• add support for IntegerAtom (previously, only IntAtom was supported)

2017-09-16 (v0.2)

• a new simple client API with a monadic transaction manager
• complete hlint compliance
• the generics-based Tupleable typeclass which makes it easy to marshal Haskell data types to-and-from the database
• timestamps attached to transactions to allow specific point-in-time travel
• autoMergeToHead, a variant of commit which attempts to merge and commit to the latest head transaction to reduce incidents of TransactionNotAHeadErrors
• interval data types
• transaction dirtiness detection which allows the client to determine if an update expression actually changed the database state

2017-08-01

autoMergeToHead

In preparation for the simpler monad client API, ProjectM36.Client now includes a server-side merge for new transactions called "automerge". This feature should reduce head contention in cases where new transactions can be simply merged to the head without additional processing. The trade-off is reduced TransactionIsNotAHeadErrors but an increased chance of merge errors. The feature operates similarly to a server-side git rebase.

critical bug in merging

Successfully merged transactions did not have their constraints validated. Fixed.

2017-06-12

add file locking

This feature allows Project:M36 database directories to be shared amongst multiple Project:M36 processes. This is similar to how SQLite operates except that the remote server mode supports the feature as well. This could allow, for example, multi-master, file-based replication across Windows shares or NFS.

Documentation

2016-11-30

add functional dependency macro

Date demonstrates two ways to implement functional dependencies as constraints on page 21 in "Database Design and Relational Theory". A similar macros is now implemented in the tutd interpreter.

funcdep sname_status (sname) -> (status) s

Documentation

2016-09-07

add TransGraphRelationalExpr

The TransGraphRelationalExpr allows queries against all past states of the database.

The following example executes a query against two different committed transactions using syntax similar to that of git for graph traversal: :showtransgraphexpr s@master~ join sp@master

Documentation