[PATCH] Make sure all statistics is sent after a few DML are performed

failed: regress/multiple-row-versions, regress/index-only-scan, regress/deadlock-simple, regress/deadlock-hard, regress/deadlock-soft, regress/deadlock-soft-2, regress/fk-contention, regress/fk-deadlock, regress/fk-deadlock2, regress/eval-plan-qual, regress/lock-update-delete, regress/lock-update-traversal, regress/insert-conflict-do-nothing, regress/insert-conflict-do-nothing-2, regress/insert-conflict-do-update, regress/insert-conflict-do-update-2, regress/insert-conflict-do-update-3, regress/insert-conflict-toast, regress/delete-abort-savept, regress/delete-abort-savept-2, regress/aborted-keyrevoke, regress/multixact-no-deadlock, regress/multixact-no-forget, regress/lock-committed-update, regress/lock-committed-keyupdate, regress/update-locked-tuple, regress/propagate-lock-delete, regress/tuplelock-conflict, regress/tuplelock-update, regress/nowait, regress/nowait-2, regress/nowait-3, regress/nowait-4, regress/nowait-5, regress/skip-locked, regress/skip-locked-2, regress/skip-locked-3, regress/skip-locked-4, regress/drop-index-concurrently-1, regress/alter-table-1, regress/alter-table-2, regress/alter-table-3, regress/create-trigger, regress/sequence-ddl, regress/async-notify, regress/vacuum-reltuples, regress/timeouts, tap/001_base