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:
Although the first solution used cereal, the final implementation uses
boost. Since the cereal is still used in the codebase, compilation has
been modified to support multithreaded cereal.
In addition to serializing Ast classes, the following also needed to be
serialized:
* GraphDbTypes
* Symbol
* TypedValue
TypedValue is treated specially, by inlining the serialization code in
the Ast class, concretely PrimitiveLiteral.
Another special case was the Function Ast class, which now stores a
function name which is resolved to a concrete std::function on
construction.
Tests have been added for serialized Ast in
tests/unit/cypher_main_visitor
Reviewers: mferencevic, mislav.bradac, florijan
Reviewed By: mislav.bradac
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D1067
Summary:
Union query combinator implementation consists of:
* adjustments to the AST and `cypher_main_visitor`
* enabling `QueryStripper` to parse multiple `return` statements (not stopping after first)
* symbol generation for union results
* union logical operator
* query plan generator adjustments
Reviewers: teon.banek, mislav.bradac
Reviewed By: teon.banek
Subscribers: pullbot, buda
Differential Revision: https://phabricator.memgraph.io/D1038
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:
- The new BFS syntax implemented as proposed.
- AST BreadthFirstAtom now uses EdgeAtom members: has_range_{true}, upper_bound_, lower_bound_
- Edges data structure now handles all the edge filtering (single or multiple edges), to ease planning. Additional edge filtering (additional Filter op in the plan) is removed. AST EdgeTypeTest is no longer used and is removed.
Current state is stable but there are things left to do:
- BFS property filtering.
- BFS lower_bound_ support.
- Support for lambdas in variable length expansion. This includes obligatory (even if not user_defined) inner_node and inner_edge symbols for easier handling.
- Code-sharing between BFS and variable length expansions.
I'll add asana tasks (and probably start working on them immediately) when/if this lands.
Reviewers: buda, teon.banek, mislav.bradac
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D836
Summary:
This is done when the generated AST will be cached.
Remove LiteralsPlugger.
Reviewers: florijan, mislav.bradac
Reviewed By: mislav.bradac
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D788
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: 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:
Add All expression to Ast
Evaluate All expression
Visit All and generate symbols
Handle All when collecting context during planning
Reviewers: florijan, mislav.bradac, buda
Reviewed By: mislav.bradac
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D587
Summary:
Allow expressions for variable length path bounds
Replace test which expected a syntax exception
Since we now allow variable length to have an arbitrary expression, the
test case is obsolete. It was replaced with something that excepts an
expression which wasn't allowed before.
Reviewers: florijan, mislav.bradac, buda
Reviewed By: mislav.bradac
Subscribers: lion, pullbot
Differential Revision: https://phabricator.memgraph.io/D568
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
Summary:
Query::Plan::RemoveProperty op added and tested
Query::AST:: Remove added to cypher main visitor. Tested. Grammar corrected on missing whitespace in removeItem production
Reviewers: buda, mislav.bradac, teon.banek
Reviewed By: mislav.bradac
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D202
Summary:
Add tests for CypherMainVisitor
Initialise members to nullptrs in ast.hpp data structures
Preserver users identifier names
Reviewers: teon.banek
Reviewed By: teon.banek
Differential Revision: https://phabricator.memgraph.io/D138
Summary: Work in progress, this is not usable yet
Reviewers: florijan
Reviewed By: florijan
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D84
