Hi, guys. In PG, there's a autovacuum daemon that's perioidically launched to remove dead tuples and marks the space available for future reuse. It will not return the space to OS. On the contrary, sqlite autovacuum will try to swap valid pages residing at the end of file with free pages, and release the tail-end pages of file back to OS. So sqlite autovacuum can shrink the file while PG autovacuum cannot. Is my understanding correct ? Any other similarities and differences ?