The total size of the in-memory database tables cannot exceed the amount of virtual memory available.

Since virtual memory is swapped to disk frequently, using virtual memory negates part of the advantage of in-memory tables. You should limit your in-memory tables to less than the size of the available physical memory, not the size of the available virtual memory.

When calculating the amount of space required for tables, do not forget BLOB data. Generally, BLOB data should be kept on disk-based tables as the maximum size of a BLOB column is significantly reduced on main-memory tables.

The amount of space required to store a table includes the space not only for the data that is in the table, but also for any indexes on that table, including any indexes created in support of primary key and foreign key constraints. Also, tables occupy significantly more space in memory than on disk.

If the server runs out of virtual memory when it tries to allocate memory (for example, to expand a table during an INSERT or ALTER TABLE operation), you will get an error message.