During save operations, Umbraco will generally take a database lock to avoid concurrency issues.
Access to this feature is via the
IScopeinterface, for example:
using (var scope = _scopeProvider.CreateScope())
// Carry out save operation.
Each lockable entity is represented by an integer Id, stored along with the state of the lock in the
Packages or custom solutions working with custom data via the
IScopeinterface can introduce their own records to this table. However it's important to not clash with either core identifiers or those introduced by other packages.
A reference is maintained here of known identifiers:
-331 to -340