github typedb/typedb 3.0.0-alpha-9
TypeDB 3.0.0-alpha-9

latest release: 3.0.0-alpha-10
pre-release12 days ago

Download from TypeDB Package Repository:

Distributions for 3.0.0-alpha-9

Pull the Docker image:

docker pull vaticle/typedb:3.0.0-alpha-9

New Features

  • Exit on panic

    In Rust, whenever a panic is encountered in a background thread, the main thread is normally unaffected until it either joins the background thread, or attempts to lock a mutex that was held by the panicking thread. If that communication never occurs (e.g. no locks were held by a worker), the server may end up in an invalid state.

    We override the default behaviour to exit from the process with code 1.

  • Stabilise fetch and introduce fetch functions
    We introduce function invocation in fetch queries. Fetch can call already existing functions:

    match
      $p isa person;
    fetch {
      "names": [ get_names($p) ],
      "age": get_age($p)
    };
    

    and also use local function blocks:

    match
      $p isa person;
    fetch {
      "names": [
        match
          $p has name $n;
          return { $n };
      ],
      "age": (
        match
          $p has age $a;
          return first $a;
      )
    };
    

    In the examples above, results collected in concept document lists ("names": [ ... ]) represent streams (purposely multiple answers), while single (optional) results ("age": ...) represent a single concept document leaf and do not require (although allow) any wrapping.

Moreover, we stabilize attribute fetching, allowing you to expect a specific concept document structure based on your schema. This way, if the attribute type is owned with default or key cardinality (@card(0..1) or @card(1..1)), meaning that there can be at most one attribute of this type, it can be fetched as a single leaf, while other cardinalities force list representation and make your system safe and consistent. For example, a query

match
  $p isa person;
fetch {
  $p.*
};

can automatically produce a document like

{
  "names": [ "Linus", "Torvalds" ],
  "age": 54
}

with

define
  entity person 
    owns name @card(1..), 
    owns age @card(1..1);

Additionally, fetch now returns attributes of all subtypes x sub name; y sub name; for $p.name, just like regular match queries like match $p owns name $n.

With this, feel free to construct your fetch statements the way you want:

match
  $p isa person, has name $name;
  fetch {
    "info": {
      "name": {
        "from entity": [ $p.person-name ],
        "from var": $name,
      },
      "optional age": $p.age,
      "rating": calculate_rating($p)
    }
  };

to expect consistent structure of the results:

[
  {
    "info": {
      "name": {
        "from entity": [ "Name1", "Surname1" ],
        "from var": "Name1"
      },
      "optional age": 25,
      "rating": 19.5
    }
  },
  {
    "info": {
      "name": {
        "from entity": [ "Name1", "Surname1" ],
        "from var": "Surname1"
      },
      "optional age": 25,
      "rating": 19.5
    }
  },
  {
    "info": {
      "name": {
        "from entity": [ "Bob" ],
        "from var": "Bob"
      },
      "optional age": null
      "rating": 28.783
    }
  }
]
  • Implement query executable cache

    We implement the cache (somewhat arbitrarily limited to 100 entries) for compiled executable queries, along with cache maintanance when statistics change significantly or the schema updates.

    Query execution without any cache hits still looks like this:

    Parsing -> Translation (to intermediate representation) -> Annotation -> Compilation -> Execution
    

    However, with a cache hit, we now have:

    Parsing -> Translation ---Cache--> Execution
    

    skipping the annotation and compilation/planning phases, which take significant time.

    Note that schema transactions don't have a query executable cache, since keeping the cache in-sync when schema operations run can be error prone.

    The query cache is a structural cache, which means it will ignore all Parameters in the query: variable names, constants and values, and fetch document keys. Most production systems run a limited set of query structures, only varying values and terms, making a structural cache like this highly effective!

  • Introduce naive retries for suspended function calls
    Introduces retries for suspended function calls.
    Functions may suspend to break cycles of recursion. Restoring suspend points is essential to completeness of recursive functions, and thus correctness of negations which call them.

  • Query execution analyser

    We implement a useful debugging feature - a query analyzer. This is similar to Postgres's Explain Analyze, which produces both the query plan plus some details about the data that has flowed through the query plan and the time at each step within it.

    Example output:

    Query profile[measurements_enabled=true]
      -----
      Stage or Pattern [id=0] - Match
        0. Sorted Iterator Intersection [bound_vars=[], output_size=1, sort_by=p0]
          [p0 isa ITEM] filter [] with (outputs=p0, )
        ==> batches: 158, rows: 10000, micros: 6407
    
        1. Sorted Iterator Intersection [bound_vars=[p0], output_size=2, sort_by=p1]
          Reverse[p1 rp p0 (role: __$2__)] filter [] with (inputs=p0, outputs=p1, checks=__$2__, )
        ==> batches: 854, rows: 39967, micros: 75716
    
      -----
      Stage or Pattern [id=1] - Reduce
        0. Reduction
        ==> batches: 1, rows: 10000, micros: 116035
    
      -----
      Stage or Pattern [id=2] - Insert
        0. Put attribute
        ==> batches: 10000, rows: 10000, micros: 5890
    
        1. Put has
        ==> batches: 10000, rows: 10000, micros: 54264
    

    When disabled, profiling is a no-op (no strings are created, locks taken, or times measured), though there is still some cost associated with cloning Arcs containing the profiling data structures around.

    To enable query profiling, the easiest way (for now) is to enable TRACE logging level for the executor package, currrently configured in //common/logger/logger.rs:

    .add_directive(LevelFilter::INFO.into())
    // add:
    // .add_directive("executor=trace".parse().unwrap())
    

    Alternatively, just set the enable boolean to true in the QueryProfile::new() constructor.

Bugs Fixed

  • Variable position fix

  • Disable variables of category value being narrow-able to attribute
    Disable variables of category value being narrowed to attribute

    $name = "some name"; $person has name == $name; # Fine
    $name == "some name"; $person has name $name; # Also Fine
    $name = "some name"; $person has name $name; # Disallowed
    
  • Fix disjunction inputs when lowering
    The disjunction compiler explicitly accepts a list of variables which are bound when the disjunction is evaluated. This also fixes a bug where input variables used in downstream steps would not be copied over.

  • Fixes early termination of type-inference pruning when disjunctions change internally
    Fixes early termination of type-inference pruning when disjunctions change internally

Code Refactors

  • Update FactoryCI images to typedb-ubuntu

  • Rename org to 'typedb' in deployment.bzl

  • Rename org to 'typedb' in CircleCI docker job

  • Boxed large result Error variants

    We follow some best practices to box the large Error variants of Result types, which should optimise both the stack size and the amount of memory that has to be copied between function calls.

  • Decimal to double cast

    We can now use decimals in double expressions.

  • Optimise has comparators and implement Executable Display

    We inline comparators into HasReverse executors, as a continuation of #7233, which inlined comparators into Isa executors. Both optimisations reduce the search space by using the value ranges provided by constants in the query or previously executed query steps. We also improve the query planner's statistics and cost function.

Other Improvements

  • Add cargo check to CI

    We add a job to Factory CI which verifies that the Cargo configuration is valid and buildable.

  • Return query operations errors on commit
    We return errors from the awaited operations on commit as the commit error. It can be useful if you want to run a number of queries from your TypeDB Driver like:

    let queries = [........];
    let mut promises = vec![];
    for query in queries {
        promises.push(transaction.query(query));
    }
    
    let result = transaction.commit().await;
    println!("Commit result will contain the unresolved query's error: {}", result.unwrap_err());
  • Update FactoryCI images to typedb-ubuntu

  • Fix structural equality test

  • Implement structural equality

    We implement a form of Structural Equality, which check the equality of two queries, in Intermediate Representation format, which allows us to compare to queries for equality while ignoring user-written variable names and function names and constants. This is a building block for the next step, which will introduce a executable cache, allowing TypeDB to skip type inference and planning for queries that already exist in the cache.

  • Deleted BUILD_java

  • Commit generated Cargo.tomls + Cargo.lock

    We commit the generated cargo manifests so that TypeDB can be built as a normal cargo project without using Bazel.

    Integration and unit tests can be run normally, and rust-analyzer behaves correctly. Behaviour tests currently cannot be run without Bazel, as the tests expect to find the feature files in bazel-typedb/external/typedb_behaviour.

    In addition, if during development the developer needs to depend on a local clone of a dependency (e.g. making parallel changes to typeql), the Cargo.toml would need to be temporarily manually adjusted to point to the path dependency.

  • Reformat import

  • Fix test assertion

  • Use type inference in sub constraints

    Previously we would use concept API to determine super / subtypes when executing as sub instruction. However, that work has already been done during type inference, so it is cheaper and more correct to reuse that work.

  • Abstract types should never be inferred for instance variables

    This PR makes makes the type checker more precise (and complain less), by excluding abstract types from being inferred for instance variables.

  • Reenable commented tests

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