Set if indexes should run purely in memory.
- Scope: Server-wide or per database
When running in memory, the index information is not written to disk and if the server is restarted all indexing data will be lost. This is mostly useful for testing or faster non-persistant indexing.
If not set or set to null - indexing will run in memory if core settings RunInMemory is set to true.
null - use the value set in core configuration RunInMemory
true - run indexing in memory
false - store information on the disk