diff --git a/src/bin/gs_guc/cluster_guc.conf b/src/bin/gs_guc/cluster_guc.conf
index bb0beef62..f9d5329d9 100755
--- a/src/bin/gs_guc/cluster_guc.conf
+++ b/src/bin/gs_guc/cluster_guc.conf
@@ -251,8 +251,8 @@ enable_show_any_tuples|bool|0,0|NULL|NULL|
 enable_sort|bool|0,0|NULL|NULL|
 enable_incremental_catchup|bool|0,0|NULL|NULL|
 wait_dummy_time|int|1,2147483647|NULL|NULL|
-heap_bulk_read_size|int|0,512|kB|Bulk blocks number for seqscan pre-read.|
-vacuum_bulk_read_size|int|0,512|kB|Bulk blocks number for vacuum pre-read.|
+heap_bulk_read_size|int|0,64|kB|Bulk blocks number for seqscan pre-read.|
+vacuum_bulk_read_size|int|0,64|kB|Bulk blocks number for vacuum pre-read.|
 max_active_global_temporary_table|int|0,1000000|NULL|NULL|
 max_inner_tool_connections|int|1,0x3FFFF|NULL|NULL|
 max_recursive_times|int|0,2147483647|NULL|NULL|
diff --git a/src/bin/gs_guc/cluster_guc.cpp b/src/bin/gs_guc/cluster_guc.cpp
index 31499ee4f..5e546e6bd 100644
--- a/src/bin/gs_guc/cluster_guc.cpp
+++ b/src/bin/gs_guc/cluster_guc.cpp
@@ -279,6 +279,8 @@ const char* unit_eight_kB_parameter_list[] = {
     "wal_buffers",
     "wal_segment_size",
     "huge_page_size",
+    "heap_bulk_read_size",
+    "vacuum_bulk_read_size"
 };
 /* the size of page, unit is kB */
 #define PAGE_SIZE 8
diff --git a/src/gausskernel/process/postmaster/checkpointer.cpp b/src/gausskernel/process/postmaster/checkpointer.cpp
index 993a57943..4d8b765ff 100755
--- a/src/gausskernel/process/postmaster/checkpointer.cpp
+++ b/src/gausskernel/process/postmaster/checkpointer.cpp
@@ -425,7 +425,7 @@ void CheckpointerMain(void)
             u_sess->stat_cxt.BgWriterStats->m_requested_checkpoints++;
         }
 
-        if (t_thrd.checkpoint_cxt.shutdown_requested) {
+        if (t_thrd.checkpoint_cxt.shutdown_requested || pmState == PM_SHUTDOWN) {
             /*
              * From here on, elog(ERROR) should end with exit(1), not send
              * control back to the sigsetjmp block above