TODOs

Phase 1 - Basic PoC

• Implement MPMCMultiframeFCFSPool
• Add helper/alias to run clang-tidy/additional checkers locally
• Implement basic Emit and Next
• Add proper logging
• Implement basic fuzzy unit test
• Implement dummy operators: ONCE, SCAN ALL, PRODUCE (mocks)
• Implement micro mocked benchmark of SingleThread physical operator execution
• Implement Frame physical operators
• Implement micro mocked benchmark Frame vs SingleThread physical operator execution
• Implement MultiThreadedExecutor based on ExecuteAsync
• Implement micro mocked benchmark Frame vs SingleThread vs Parallel physical operator execution
• Change DataPool::PoolState to be composable + implement call skips when possible (inside Executor)
• Write the spec, list pros and cons of this architecture

Phase 2 - Proof it works in the long run

• Basic refactor
  • Measure latency with different multiframe number and size
  • Implement Unwind and CreateVertices (state objects + execution)
  • Add the ability to return the Multiframe back to the data pool (NOTE: not marking it as empty)
  • Make Executor throw in all non-linear cases (e.g. OPTIONAL MATCH not supported)
• Implement e2e operators (inject real storage, not mocks):
  • ONCE
  • SCAN ALL
  • CREATE NODE (write, WITH accumulate)
  • UNWIND (multiframe expansion)
  • PRODUCE
• Inject implementation e2e
  • Create v1 and v2 of tests/manual/interactive/*
• Implement basic e2e test
• Implement basic e2e benchmark
• Add support for single-operator parallelization and benchmark "level-sync" executor
• Implement and test other important operators (order is important + all tricky things should be covered by implementing this set of operators):
  • CREATE EXPAND (write, WITH accumulate)
  • EXPAND (basic graph DB operator)
  • VARIABLE EXPAND (graph traversals)
  • FILTER (multiframe reduction)
  • WITH (aggregation)
  • OPTIONAL MATCH (double branch query plan)
  • MERGE (triple branch query plan)
• Implement Cancel
• Implement Timeout
• Implement Shutdown
• Add allocator
• Implement dummy authentication and authorization

Phase 3 - Implement the whole query engine

• Implement all operators
• Implement the whole authentication and authorization
• Benchmark and improve all operators
• Add detailed documentation

NOTE: Migrated from memgraph#640