When DB2 performs an index or table scan, DB2 will block on a row lock when it comes across an uncommitted row which another transaction has exclusively (X) locked.

For MDC tables, the selection of BLOCKINSERT may improve the performance of INSERT operations by locking at the block level and avoiding row locks for INSERT operations.

The solidDB solution is made possible by the ability to allocate row images and row shadow images (different versions of the same row) without using inefficient block structures.