Summary:
- GC changed to evaluate old records w.r.t. the oldest transaction's id AND snapshot, as opposed to only id
- MVCC hints exp+aborted race condition prevented
- minor MVCC refactors and cleanups
- minor Transaction refactors and cleanups
Reviewers: buda, dgleich
Reviewed By: buda, dgleich
Subscribers: dtomicevic, pullbot
Differential Revision: https://phabricator.memgraph.io/D434
Summary:
When running tck tests there was a peculiar behavior where sometimes some queries worked, and sometimes they failed. Nothing was failing when memgraph was restarted between each query (scenario) - which points to MATCH DETACH DELETE not working correctly.
What was happening is the following: some transaction would update the record in version list and set it's expiry to it's id. Along with that some transaction would query the mentioned record - and would set the hints flags for that expiration transaction status (which was aborted - which is fine at this moment). After some while, because the record is not really deleted because it's not aborted some other transaction would modify it's expiry transaction (this time making the transaction commited), but because the hints flags were not updated - they would still return the status for the old transaction - which was aborted. This made some records available even though they were deleted.
Reviewers: mislav.bradac, florijan, teon.banek, matej.gradicek, buda
Reviewed By: buda
Subscribers: buda, lion, pullbot
Differential Revision: https://phabricator.memgraph.io/D370
Summary:
The GraphDbAccessor and KeyIndex APIs can now also return records for the current transaction+command graph state. This is necessary to correctly implement MERGE. The new logic is has increased the MVCC+Accessor related chaos and should be revised when refactoring MVCC (as planned).
Previous index testing was separated into VertexIndex and EdgeIndex testing. This is inappropriate since most of the logic is exaclty the same. Also it was not clearly defined what gets tested via the GraphDbAccessor API, and what directly through the KeyIndex API. This has also been refactored, but it needs additional work (Gleich).
Reviewers: buda, dgleich
Reviewed By: buda, dgleich
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D306
Summary:
The rest of core engine exceptions are extended from the BasicException (because of the error handling in the communication stack). Maximum value of the MVCC command id is calculated in the compile time.
I've put the tasks to implement concurrent tests in the qa repo in the backlog. Hopefully they will be implemented within this sprint.
Reviewers: mislav.bradac, mferencevic, florijan
Reviewed By: mislav.bradac
Subscribers: dgleich, pullbot, buda
Differential Revision: https://phabricator.memgraph.io/D298
Summary: Changing mvcc again. This should be double-checked since it's quite a substantial change. The test here tests for the new behaviour - which should be correct.
Reviewers: matej.gradicek, dtomicevic, buda
Reviewed By: matej.gradicek, buda
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D156
Summary: Query - ExpandCreate op added (with tests). LogicalOp tests have property enabled. MATCH-CREATE test started but disabled due to MVCC.
Reviewers: buda, mislav.bradac, teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D150
