Summary:
GraphDb is refactored to become an API exposing different parts
necessary for the database to function. These different parts can have
different implementations in SingleNode or distributed Master/Server
GraphDb implementations.
Interally GraphDb is implemented using two class heirarchies. One
contains all the members and correct wiring for each situation. The
other takes care of initialization and shutdown. This architecture is
practical because it can guarantee that the initialization of the
object structure is complete, before initializing state.
Reviewers: buda, mislav.bradac, dgleich, teon.banek
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1093
Summary:
Remove name from GraphDb.
Take GraphDb in query test macros instead of accessor.
Add is_accepting_transactions flag to GraphDb.
Reviewers: mislav.bradac, florijan, mferencevic
Reviewed By: mislav.bradac
Subscribers: mferencevic, pullbot
Differential Revision: https://phabricator.memgraph.io/D940
Summary:
- Removed BreadthFirstAtom, using EdgeAtom only with a Type enum.
- Both variable expansions (breadth and depth first) now have mandatory inner node and edge Identifiers.
- Both variable expansions use inline property filtering and support inline lambdas.
- BFS and variable expansion now have the same planning process.
- Planner modified in the following ways:
- Variable expansions support inline property filtering (two filters added to all_filters, one for inline, one for post-expand).
- Asserting against existing_edge since we don't support that anymore.
- Edge and node symbols bound after variable expansion to disallow post-expand filters to get inlined.
- Some things simplified due to different handling.
- BreadthFirstExpand logical operator merged into ExpandVariable. Two Cursor classes remain and are dynamically chosen from.
As part of planned planner refactor we should ensure that a filter is applied only once. The current implementation is very suboptimal for property filtering in variable expansions.
@buda: we will start refactoring this these days. This current planner logic is too dense and complex. It is becoming technical debt. Most of the time I spent working on this has been spent figuring the planning out, and I still needed Teon's help at times. Implementing the correct and optimal version of query execution (avoiding multiple potentially expensive filterings) was out of reach also due to tech debt.
Reviewers: buda, teon.banek
Reviewed By: teon.banek
Subscribers: pullbot, buda
Differential Revision: https://phabricator.memgraph.io/D852
Summary: - modified all utils/algorithm functions to be inline and in the utils namespace
Reviewers: teon.banek
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D830
Summary:
Antlr grammar has been updated to support putting edge types after the BFS
symbol. Planner collects edge type filters for BFS and inlines them in the
operator by joining the filter with the user input BFS filter itself. This
requires no change from the standpoint of the operator. On the other hand, in
order to use the faster lookup by a single edge type, `ExpandBreadthFirst`
operator now accept an optional edge type. The edge type is passed from the
planner only if the user is filtering by a single type.
Unit tests as well as tck have been updated.
Reviewers: florijan, mislav.bradac
Reviewed By: florijan
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D777
Summary:
Add function First to utils.
Insert EdgeType into Expand during planning.
Reviewers: florijan, mislav.bradac
Reviewed By: florijan
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D769
Summary:
This allows for inserting dummy DbAccessor in tests. Unfortunate side
effect of this change is that the whole implementation had to be moved
from cpp to hpp.
Also templatize remaining RuleBasedPlanner implementation
Reviewers: florijan, mislav.bradac
Reviewed By: mislav.bradac
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D704
Summary:
This is needed in cases when the planner decides to start expanding from
the other end.
Reviewers: mislav.bradac, florijan
Reviewed By: mislav.bradac
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D681
Summary: Not strictly neccessary, but it's been itching me. It took an hour.
Reviewers: buda, mislav.bradac
Reviewed By: mislav.bradac
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D648
Summary:
Now all ScanAll and Expand ops are covered by the cost estimator. For ScanAll with indices cost estimation is pretty good, for new Expand ops it is tragically bad (Expand to the power of expansion depth, plus arbitrary filtering). Static cost estimation is wrong wrong wrong.
Currently cost estimation of even trivial plans that use indices is wrong because the planner leaves filtering expressions that are implicitly handled by the index in the operator tree, IIRC. Tasking Teon to revise this, even though I'm not sure how bad an influence this has on cost estimation and it's use in plan choosing.
Reviewers: mislav.bradac, teon.banek, buda
Reviewed By: mislav.bradac
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D633
Summary:
There was only two files in dbms directory so I moved them to database
directory.
Reviewers: buda
Reviewed By: buda
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D540
