Summary:
The garbage collector had a race condition when it would delete deltas that
were in the middle of an object's delta chain. In the process of deleting
(unlinking) the delta, the garbage collector previously wouldn't acquire any
locks. That operation was then racing with the standard MVCC
`CreateAndLinkDelta` function that adds a new delta into the chain.
Fortunately, `CreateAndLinkDelta` always does its modifications while holding a
lock to the owner of the chain (either a vertex or an edge) so this change just
adds the lock acquiring to the garbage collector.
Reviewers: teon.banek
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D2582
Summary:
This change implements full edges support in storage v2. Edges can be created
and deleted. Support for detach-deleting vertices is added and regular vertex
deletion verifies existance of edges.
Reviewers: mtomic, teon.banek
Reviewed By: mtomic
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D2180
Summary:
Initial implementation of new storage engine. It implements snapshot isolation
for transactions. All changes in the database are stored as deltas instead of
making full copies. Currently, the storage supports full transaction
functionality (commit, abort, command advancement). Also, support has been
implemented only for vertices that have only labels.
Reviewers: teon.banek, mtomic
Reviewed By: teon.banek
Subscribers: pullbot
Differential Revision: https://phabricator.memgraph.io/D2138
