Use Case

Memtable scan in OB has to return rows one by one, which is not very performance friendly when large amounts of data only exists in memtable. This can be attributed to two reasons (1) single edge scan does not support memtable scan iterator; (2) when there are additional filters, it has to calculate row by row (check_filtered function). If the filter is complex, this part of the computational overhead may be very large.

Describe the solution you'd like

(1) First, enable single edge table scan for memtable, which is the basis for later optimization.
(2) Second, acquire a batch of rows instead of only one.
(3) Third, use bitmap result to calculate the whole batch.

Describe alternatives you've considered

Additional context