diff --git a/mysql-test/include/analyze-format.inc b/mysql-test/include/analyze-format.inc
index 08006e26c79..330be82ef96 100644
--- a/mysql-test/include/analyze-format.inc
+++ b/mysql-test/include/analyze-format.inc
@@ -1,3 +1,3 @@
 # The time on ANALYSE FORMAT=JSON is rather variable
 
---replace_regex /("(r_total_time_ms|r_buffer_size|r_filling_time_ms)": )[^, \n]*/\1"REPLACED"/
+--replace_regex /("(r_[a-z_]*_time_ms|r_buffer_size)": )[^, \n]*/\1"REPLACED"/
diff --git a/mysql-test/main/analyze_format_json.result b/mysql-test/main/analyze_format_json.result
index c306c2fc1b3..48a12125f98 100644
--- a/mysql-test/main/analyze_format_json.result
+++ b/mysql-test/main/analyze_format_json.result
@@ -145,7 +145,8 @@ ANALYZE
       "buffer_type": "flat",
       "buffer_size": "1Kb",
       "join_type": "BNL",
-      "r_filtered": 100
+      "r_filtered": 100,
+      "r_unpack_time_ms": "REPLACED"
     }
   }
 }
@@ -184,7 +185,8 @@ ANALYZE
       "buffer_size": "1Kb",
       "join_type": "BNL",
       "attached_condition": "tbl1.c > tbl2.c",
-      "r_filtered": 15.833
+      "r_filtered": 15.833,
+      "r_unpack_time_ms": "REPLACED"
     }
   }
 }
@@ -628,7 +630,8 @@ ANALYZE
       "buffer_size": "65",
       "join_type": "BNL",
       "attached_condition": "<in_optimizer>(t2.b,t2.b in (subquery#2))",
-      "r_filtered": null
+      "r_filtered": null,
+      "r_unpack_time_ms": "REPLACED"
     },
     "subqueries": [
       {
@@ -713,7 +716,8 @@ ANALYZE
               "buffer_type": "flat",
               "buffer_size": "1",
               "join_type": "BNL",
-              "r_filtered": null
+              "r_filtered": null,
+              "r_unpack_time_ms": "REPLACED"
             },
             "subqueries": [
               {
@@ -745,7 +749,8 @@ ANALYZE
                       "buffer_size": "65",
                       "join_type": "BNL",
                       "attached_condition": "t2.f2 = t3.f3",
-                      "r_filtered": null
+                      "r_filtered": null,
+                      "r_unpack_time_ms": "REPLACED"
                     }
                   }
                 }
diff --git a/mysql-test/main/analyze_format_json_timings.result b/mysql-test/main/analyze_format_json_timings.result
new file mode 100644
index 00000000000..f00833b40eb
--- /dev/null
+++ b/mysql-test/main/analyze_format_json_timings.result
@@ -0,0 +1,85 @@
+#
+# MDEV-30830: ANALYZE FORMAT=JSON: r_unpack_time_ms is empty for the hashed joins
+#
+#
+# First, check a regular BNL-join
+#
+create table t1 (
+a int,
+b int
+);
+insert into t1 select seq, seq/3 from seq_0_to_99;
+create table t2 (
+a int,
+b int
+);
+insert into t2 select seq, seq/5 from seq_0_to_99;
+set @js='$out';
+set @out=(select json_extract(@js,'$**.block-nl-join.r_unpack_time_ms'));
+select cast(json_extract(@out,'$[0]') as DOUBLE) > 0;
+cast(json_extract(@out,'$[0]') as DOUBLE) > 0
+1
+drop table t1,t2;
+#
+# Now, check the hashed, BNL-H join
+#
+create table t1 (
+a int,
+b int
+);
+insert into t1 select seq, seq/3 from seq_0_to_499;
+create table t2 (
+a int,
+b int
+);
+insert into t2 select seq, seq/5 from seq_0_to_499;
+set @tmp=@@join_cache_level, join_cache_level=6;
+select '$out' as X;
+X
+{
+  "query_block": {
+    "select_id": 1,
+    "r_loops": 1,
+    "r_total_time_ms": "REPLACED",
+    "table": {
+      "table_name": "t1",
+      "access_type": "ALL",
+      "r_loops": 1,
+      "rows": 500,
+      "r_rows": 500,
+      "r_total_time_ms": "REPLACED",
+      "filtered": 100,
+      "r_filtered": 100,
+      "attached_condition": "t1.a < 700 and t1.b is not null"
+    },
+    "block-nl-join": {
+      "table": {
+        "table_name": "t2",
+        "access_type": "hash_ALL",
+        "key": "#hash#$hj",
+        "key_length": "5",
+        "used_key_parts": ["b"],
+        "ref": ["test.t1.b"],
+        "r_loops": 1,
+        "rows": 500,
+        "r_rows": 500,
+        "r_total_time_ms": "REPLACED",
+        "filtered": 100,
+        "r_filtered": 20,
+        "attached_condition": "t2.a < 100"
+      },
+      "buffer_type": "flat",
+      "buffer_size": "18Kb",
+      "join_type": "BNLH",
+      "attached_condition": "t2.b = t1.b",
+      "r_filtered": 100,
+      "r_unpack_time_ms": "REPLACED"
+    }
+  }
+}
+set @out=(select json_extract(@js,'$**.block-nl-join.r_unpack_time_ms'));
+select cast(json_extract(@out,'$[0]') as DOUBLE) > 0;
+cast(json_extract(@out,'$[0]') as DOUBLE) > 0
+1
+set join_cache_level=@tmp;
+drop table t1, t2;
diff --git a/mysql-test/main/analyze_format_json_timings.test b/mysql-test/main/analyze_format_json_timings.test
new file mode 100644
index 00000000000..fdb4c8d5989
--- /dev/null
+++ b/mysql-test/main/analyze_format_json_timings.test
@@ -0,0 +1,77 @@
+#
+#  Tests to check that r_something_time_ms is non-zero in
+#    ANALYZE FORMAT=JSON <statement>
+#
+--source include/default_optimizer_switch.inc
+--source include/have_sequence.inc
+
+# The tests here are large so that we get non-zero timings
+--source include/big_test.inc
+
+--echo #
+--echo # MDEV-30830: ANALYZE FORMAT=JSON: r_unpack_time_ms is empty for the hashed joins
+--echo #
+
+--echo #
+--echo # First, check a regular BNL-join
+--echo #
+create table t1 (
+  a int,
+  b int
+);
+insert into t1 select seq, seq/3 from seq_0_to_99;
+
+create table t2 (
+  a int,
+  b int
+);
+insert into t2 select seq, seq/5 from seq_0_to_99;
+
+let $out=`
+analyze format=json
+select * from t1, t2
+where
+ t1.a < 700 and
+ t2.a < 100
+ and t1.b=t2.b
+`;
+
+evalp set @js='$out';
+set @out=(select json_extract(@js,'$**.block-nl-join.r_unpack_time_ms'));
+select cast(json_extract(@out,'$[0]') as DOUBLE) > 0;
+drop table t1,t2;
+
+--echo #
+--echo # Now, check the hashed, BNL-H join
+--echo #
+create table t1 (
+  a int,
+  b int
+);
+insert into t1 select seq, seq/3 from seq_0_to_499;
+
+create table t2 (
+  a int,
+  b int
+);
+insert into t2 select seq, seq/5 from seq_0_to_499;
+set @tmp=@@join_cache_level, join_cache_level=6;
+
+let $out=`
+analyze format=json
+select * from t1, t2
+where
+ t1.a < 700 and
+ t2.a < 100
+ and t1.b=t2.b
+`;
+
+--source include/analyze-format.inc
+evalp select '$out' as X;
+
+set @out=(select json_extract(@js,'$**.block-nl-join.r_unpack_time_ms'));
+select cast(json_extract(@out,'$[0]') as DOUBLE) > 0;
+
+set join_cache_level=@tmp;
+drop table t1, t2;
+
diff --git a/mysql-test/main/analyze_stmt_orderby.result b/mysql-test/main/analyze_stmt_orderby.result
index 23f4c39dd5b..fbd57078b8e 100644
--- a/mysql-test/main/analyze_stmt_orderby.result
+++ b/mysql-test/main/analyze_stmt_orderby.result
@@ -429,7 +429,8 @@ ANALYZE
           "buffer_size": "65",
           "join_type": "BNL",
           "attached_condition": "t3.a = t0.a",
-          "r_filtered": 10
+          "r_filtered": 10,
+          "r_unpack_time_ms": "REPLACED"
         }
       }
     }
@@ -500,7 +501,8 @@ ANALYZE
               "buffer_size": "119",
               "join_type": "BNL",
               "attached_condition": "t5.a = t6.a",
-              "r_filtered": 21.429
+              "r_filtered": 21.429,
+              "r_unpack_time_ms": "REPLACED"
             }
           }
         }
diff --git a/mysql-test/main/derived_split_innodb.result b/mysql-test/main/derived_split_innodb.result
index bea2271eaf3..22974251c56 100644
--- a/mysql-test/main/derived_split_innodb.result
+++ b/mysql-test/main/derived_split_innodb.result
@@ -461,7 +461,8 @@ ANALYZE
             "buffer_size": "1Kb",
             "join_type": "BNL",
             "attached_condition": "trigcond(t11.col1 = t10.col1)",
-            "r_filtered": 10
+            "r_filtered": 10,
+            "r_unpack_time_ms": "REPLACED"
           }
         }
       }
diff --git a/mysql-test/main/except.result b/mysql-test/main/except.result
index c96ba62a215..6b629cb6a0f 100644
--- a/mysql-test/main/except.result
+++ b/mysql-test/main/except.result
@@ -327,7 +327,8 @@ ANALYZE
               "buffer_type": "flat",
               "buffer_size": "119",
               "join_type": "BNL",
-              "r_filtered": 100
+              "r_filtered": 100,
+              "r_unpack_time_ms": 0.0012
             }
           }
         },
@@ -361,7 +362,8 @@ ANALYZE
               "buffer_type": "flat",
               "buffer_size": "119",
               "join_type": "BNL",
-              "r_filtered": 100
+              "r_filtered": 100,
+              "r_unpack_time_ms": 5.4e-4
             }
           }
         }
@@ -423,7 +425,8 @@ ANALYZE
                     "buffer_type": "flat",
                     "buffer_size": "119",
                     "join_type": "BNL",
-                    "r_filtered": 100
+                    "r_filtered": 100,
+                    "r_unpack_time_ms": 0.0011
                   }
                 }
               },
@@ -457,7 +460,8 @@ ANALYZE
                     "buffer_type": "flat",
                     "buffer_size": "119",
                     "join_type": "BNL",
-                    "r_filtered": 100
+                    "r_filtered": 100,
+                    "r_unpack_time_ms": 6.1e-4
                   }
                 }
               }
diff --git a/mysql-test/main/except.test b/mysql-test/main/except.test
index 4eaae1a3888..80df958c354 100644
--- a/mysql-test/main/except.test
+++ b/mysql-test/main/except.test
@@ -14,8 +14,10 @@ EXPLAIN extended select * from ((select a,b from t1) except (select c,d from t2)
 EXPLAIN format=json (select a,b from t1) except (select c,d from t2);
 
 --replace_regex /"r_total_time_ms": [0-9e\.\-+]*,/"r_total_time_ms": "REPLACED",/
+--source include/analyze-format.inc
 ANALYZE format=json (select a,b from t1) except (select c,d from t2);
 --replace_regex /"r_total_time_ms": [0-9e\.\-+]*,/"r_total_time_ms": "REPLACED",/
+--source include/analyze-format.inc
 ANALYZE format=json select * from ((select a,b from t1) except (select c,d from t2)) a;
 select * from ((select a,b from t1) except (select c,d from t2)) a;
 
diff --git a/mysql-test/main/explain_json.result b/mysql-test/main/explain_json.result
index 17f83fe5362..b0ea1d273fb 100644
--- a/mysql-test/main/explain_json.result
+++ b/mysql-test/main/explain_json.result
@@ -1536,7 +1536,8 @@ ANALYZE
       "buffer_size": "400",
       "join_type": "BKA",
       "mrr_type": "Rowid-ordered scan",
-      "r_filtered": 100
+      "r_filtered": 100,
+      "r_unpack_time_ms": "REPLACED"
     }
   }
 }
diff --git a/mysql-test/main/intersect.result b/mysql-test/main/intersect.result
index e4a8300ec74..a32a79c0043 100644
--- a/mysql-test/main/intersect.result
+++ b/mysql-test/main/intersect.result
@@ -385,7 +385,8 @@ ANALYZE
               "buffer_type": "flat",
               "buffer_size": "256Kb",
               "join_type": "BNL",
-              "r_filtered": 100
+              "r_filtered": 100,
+              "r_unpack_time_ms": 6.1e-4
             }
           }
         }
@@ -464,7 +465,8 @@ ANALYZE
                     "buffer_type": "flat",
                     "buffer_size": "256Kb",
                     "join_type": "BNL",
-                    "r_filtered": 100
+                    "r_filtered": 100,
+                    "r_unpack_time_ms": 5.8e-4
                   }
                 }
               }
diff --git a/mysql-test/main/rowid_filter_innodb.result b/mysql-test/main/rowid_filter_innodb.result
index 6bc00da6f4c..6248932d666 100644
--- a/mysql-test/main/rowid_filter_innodb.result
+++ b/mysql-test/main/rowid_filter_innodb.result
@@ -3634,7 +3634,8 @@ ANALYZE
       "join_type": "BKA",
       "mrr_type": "Rowid-ordered scan",
       "attached_condition": "a.atp = 1",
-      "r_filtered": 100
+      "r_filtered": 100,
+      "r_unpack_time_ms": "REPLACED"
     },
     "block-nl-join": {
       "table": {
@@ -3657,7 +3658,8 @@ ANALYZE
       "join_type": "BKA",
       "mrr_type": "Rowid-ordered scan",
       "attached_condition": "fi.fh in (6311439873746261694,-397087483897438286,8518228073041491534,-5420422472375069774)",
-      "r_filtered": 40
+      "r_filtered": 40,
+      "r_unpack_time_ms": "REPLACED"
     }
   }
 }
diff --git a/sql/sql_explain.cc b/sql/sql_explain.cc
index 6b76db8139e..78f2d5e9254 100644
--- a/sql/sql_explain.cc
+++ b/sql/sql_explain.cc
@@ -1904,6 +1904,9 @@ void Explain_table_access::print_explain_json(Explain_query *query,
         writer->add_double(jbuf_tracker.get_filtered_after_where()*100.0);
       else
         writer->add_null();
+
+      writer->add_member("r_unpack_time_ms");
+      writer->add_double(jbuf_unpack_tracker.get_time_ms());
     }
   }
 
diff --git a/sql/sql_explain.h b/sql/sql_explain.h
index 3add40419cf..2be6390e2cf 100644
--- a/sql/sql_explain.h
+++ b/sql/sql_explain.h
@@ -721,7 +721,7 @@ public:
 class Explain_table_access : public Sql_alloc
 {
 public:
-  Explain_table_access(MEM_ROOT *root) :
+  Explain_table_access(MEM_ROOT *root, bool timed) :
     derived_select_number(0),
     non_merged_sjm_number(0),
     extra_tags(root),
@@ -734,6 +734,7 @@ public:
     pushed_index_cond(NULL),
     sjm_nest(NULL),
     pre_join_sort(NULL),
+    jbuf_unpack_tracker(timed),
     rowid_filter(NULL)
   {}
   ~Explain_table_access() { delete sjm_nest; }
@@ -840,7 +841,12 @@ public:
   Table_access_tracker tracker;
   Exec_time_tracker op_tracker;
   Table_access_tracker jbuf_tracker;
-  
+
+  /*
+    Track the time to unpack rows from the join buffer.
+  */
+  Time_and_counter_tracker jbuf_unpack_tracker;
+
   Explain_rowid_filter *rowid_filter;
 
   int print_explain(select_result_sink *output, uint8 explain_flags, 
diff --git a/sql/sql_join_cache.cc b/sql/sql_join_cache.cc
index 26716a4a5c4..41d7dd89f55 100644
--- a/sql/sql_join_cache.cc
+++ b/sql/sql_join_cache.cc
@@ -1638,7 +1638,7 @@ bool JOIN_CACHE::get_record()
     pos+= referenced_fields*size_of_fld_ofs;
     if (prev_cache)
       prev_cache->get_record_by_pos(prev_rec_ptr);
-  } 
+  }
   return res; 
 }
 
@@ -2414,7 +2414,9 @@ enum_nested_loop_state JOIN_CACHE::join_matching_records(bool skip_last)
             (join_tab->first_inner && !not_exists_opt_is_applicable))) ||
           !skip_next_candidate_for_match(rec_ptr))
       {
-	read_next_candidate_for_match(rec_ptr);
+        ANALYZE_START_TRACKING(join_tab->jbuf_unpack_tracker);
+        read_next_candidate_for_match(rec_ptr);
+        ANALYZE_STOP_TRACKING(join_tab->jbuf_unpack_tracker);
         rc= generate_full_extensions(rec_ptr);
         if (rc != NESTED_LOOP_OK && rc != NESTED_LOOP_NO_MORE_ROWS)
 	  goto finish;   
diff --git a/sql/sql_select.cc b/sql/sql_select.cc
index e3a3a33a7c1..ec66d0baf31 100644
--- a/sql/sql_select.cc
+++ b/sql/sql_select.cc
@@ -26906,6 +26906,7 @@ bool JOIN_TAB::save_explain_data(Explain_table_access *eta,
   // psergey-todo: data for filtering!
   tracker= &eta->tracker;
   jbuf_tracker= &eta->jbuf_tracker;
+  jbuf_unpack_tracker= &eta->jbuf_unpack_tracker;
 
   /* Enable the table access time tracker only for "ANALYZE stmt" */
   if (thd->lex->analyze_stmt)
@@ -27536,7 +27537,8 @@ int JOIN::save_explain_data_intern(Explain_query *output,
 
 
       Explain_table_access *eta= (new (output->mem_root)
-                                  Explain_table_access(output->mem_root));
+                                  Explain_table_access(output->mem_root,
+                                                       thd->lex->analyze_stmt));
 
       if (!eta)
         DBUG_RETURN(1);
diff --git a/sql/sql_select.h b/sql/sql_select.h
index b0fa0b66b62..7282a83ef09 100644
--- a/sql/sql_select.h
+++ b/sql/sql_select.h
@@ -309,6 +309,7 @@ typedef struct st_join_table {
   Table_access_tracker *tracker;
 
   Table_access_tracker *jbuf_tracker;
+  Time_and_counter_tracker *jbuf_unpack_tracker;
   /* 
     Bitmap of TAB_INFO_* bits that encodes special line for EXPLAIN 'Extra'
     column, or 0 if there is no info.