diff --git a/pkg/ccl/logictestccl/testdata/logic_test/regional_by_row_query_behavior b/pkg/ccl/logictestccl/testdata/logic_test/regional_by_row_query_behavior
index 593dfda9e84a..93a1c77ba8ac 100644
--- a/pkg/ccl/logictestccl/testdata/logic_test/regional_by_row_query_behavior
+++ b/pkg/ccl/logictestccl/testdata/logic_test/regional_by_row_query_behavior
@@ -618,7 +618,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
 Scan /Table/62/1/"@"/10/0, /Table/62/1/"\x80"/10/0, /Table/62/1/"\xc0"/10/0
 fetched: /child/child_pkey/?/10/c_p_id -> /10
 Scan /Table/61/1/"@"/10/0, /Table/61/1/"\x80"/10/0, /Table/61/1/"\xc0"/10/0
-fetched: /parent/parent_pkey/?/? -> NULL
+fetched: /parent/parent_pkey/?/? -> <undecoded>
 
 # Semi join with locality optimized search disabled.
 query T
@@ -648,7 +648,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
 Scan /Table/62/1/"@"/10/0, /Table/62/1/"\x80"/10/0, /Table/62/1/"\xc0"/10/0
 fetched: /child/child_pkey/?/10/c_p_id -> /10
 Scan /Table/61/1/"@"/10/0, /Table/61/1/"\x80"/10/0, /Table/61/1/"\xc0"/10/0
-fetched: /parent/parent_pkey/?/? -> NULL
+fetched: /parent/parent_pkey/?/? -> <undecoded>
 output row: [10 10]
 
 # Inner join with locality optimized search disabled.
@@ -679,7 +679,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
 Scan /Table/62/1/"@"/10/0, /Table/62/1/"\x80"/10/0, /Table/62/1/"\xc0"/10/0
 fetched: /child/child_pkey/?/10/c_p_id -> /10
 Scan /Table/61/1/"@"/10/0, /Table/61/1/"\x80"/10/0, /Table/61/1/"\xc0"/10/0
-fetched: /parent/parent_pkey/'ap-southeast-2'/10 -> NULL
+fetched: /parent/parent_pkey/'ap-southeast-2'/10 -> <undecoded>
 output row: [10 10 10]
 
 # Left join with locality optimized search disabled.
@@ -710,7 +710,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
 Scan /Table/62/1/"@"/10/0, /Table/62/1/"\x80"/10/0, /Table/62/1/"\xc0"/10/0
 fetched: /child/child_pkey/?/10/c_p_id -> /10
 Scan /Table/61/1/"@"/10/0, /Table/61/1/"\x80"/10/0, /Table/61/1/"\xc0"/10/0
-fetched: /parent/parent_pkey/'ap-southeast-2'/10 -> NULL
+fetched: /parent/parent_pkey/'ap-southeast-2'/10 -> <undecoded>
 output row: [10 10 10]
 
 statement ok
@@ -777,7 +777,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
 Scan /Table/62/1/"@"/10/0
 fetched: /child/child_pkey/?/10/c_p_id -> /10
 Scan /Table/61/1/"@"/10/0
-fetched: /parent/parent_pkey/?/? -> NULL
+fetched: /parent/parent_pkey/?/? -> <undecoded>
 
 statement ok
 SET tracing = on,kv,results; SELECT * FROM child WHERE NOT EXISTS (SELECT * FROM parent WHERE p_id = c_p_id) AND c_id = 20; SET tracing = off
@@ -795,7 +795,7 @@ Scan /Table/62/1/"\x80"/20/0, /Table/62/1/"\xc0"/20/0
 fetched: /child/child_pkey/?/20/c_p_id -> /20
 Scan /Table/61/1/"@"/20/0
 Scan /Table/61/1/"\x80"/20/0, /Table/61/1/"\xc0"/20/0
-fetched: /parent/parent_pkey/?/? -> NULL
+fetched: /parent/parent_pkey/?/? -> <undecoded>
 
 # Semi join with locality optimized search enabled.
 query T
@@ -853,7 +853,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
 Scan /Table/62/1/"@"/10/0
 fetched: /child/child_pkey/?/10/c_p_id -> /10
 Scan /Table/61/1/"@"/10/0
-fetched: /parent/parent_pkey/?/? -> NULL
+fetched: /parent/parent_pkey/?/? -> <undecoded>
 output row: [10 10]
 
 statement ok
@@ -872,7 +872,7 @@ Scan /Table/62/1/"\x80"/20/0, /Table/62/1/"\xc0"/20/0
 fetched: /child/child_pkey/?/20/c_p_id -> /20
 Scan /Table/61/1/"@"/20/0
 Scan /Table/61/1/"\x80"/20/0, /Table/61/1/"\xc0"/20/0
-fetched: /parent/parent_pkey/?/? -> NULL
+fetched: /parent/parent_pkey/?/? -> <undecoded>
 output row: [20 20]
 
 # Inner join with locality optimized search enabled.
@@ -931,7 +931,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
 Scan /Table/62/1/"@"/10/0
 fetched: /child/child_pkey/?/10/c_p_id -> /10
 Scan /Table/61/1/"@"/10/0
-fetched: /parent/parent_pkey/'ap-southeast-2'/10 -> NULL
+fetched: /parent/parent_pkey/'ap-southeast-2'/10 -> <undecoded>
 output row: [10 10 10]
 
 statement ok
@@ -950,7 +950,7 @@ Scan /Table/62/1/"\x80"/20/0, /Table/62/1/"\xc0"/20/0
 fetched: /child/child_pkey/?/20/c_p_id -> /20
 Scan /Table/61/1/"@"/20/0
 Scan /Table/61/1/"\x80"/20/0, /Table/61/1/"\xc0"/20/0
-fetched: /parent/parent_pkey/'ca-central-1'/20 -> NULL
+fetched: /parent/parent_pkey/'ca-central-1'/20 -> <undecoded>
 output row: [20 20 20]
 
 # Left join with locality optimized search enabled.
@@ -1009,7 +1009,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
 Scan /Table/62/1/"@"/10/0
 fetched: /child/child_pkey/?/10/c_p_id -> /10
 Scan /Table/61/1/"@"/10/0
-fetched: /parent/parent_pkey/'ap-southeast-2'/10 -> NULL
+fetched: /parent/parent_pkey/'ap-southeast-2'/10 -> <undecoded>
 output row: [10 10 10]
 
 statement ok
@@ -1028,7 +1028,7 @@ Scan /Table/62/1/"\x80"/20/0, /Table/62/1/"\xc0"/20/0
 fetched: /child/child_pkey/?/20/c_p_id -> /20
 Scan /Table/61/1/"@"/20/0
 Scan /Table/61/1/"\x80"/20/0, /Table/61/1/"\xc0"/20/0
-fetched: /parent/parent_pkey/'ca-central-1'/20 -> NULL
+fetched: /parent/parent_pkey/'ca-central-1'/20 -> <undecoded>
 output row: [20 20 20]
 
 query T
diff --git a/pkg/sql/colfetcher/cfetcher.go b/pkg/sql/colfetcher/cfetcher.go
index d8a7ed9f7953..05a0898c7a88 100644
--- a/pkg/sql/colfetcher/cfetcher.go
+++ b/pkg/sql/colfetcher/cfetcher.go
@@ -1176,7 +1176,7 @@ func (rf *cFetcher) processValue(ctx context.Context, familyID descpb.FamilyID)
 	}
 
 	if rf.traceKV && prettyValue == "" {
-		prettyValue = tree.DNull.String()
+		prettyValue = "<undecoded>"
 	}
 
 	return nil
diff --git a/pkg/sql/opt/exec/execbuilder/testdata/aggregate b/pkg/sql/opt/exec/execbuilder/testdata/aggregate
index 755c141489ee..c71fc86a7baa 100644
--- a/pkg/sql/opt/exec/execbuilder/testdata/aggregate
+++ b/pkg/sql/opt/exec/execbuilder/testdata/aggregate
@@ -727,7 +727,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /xyz/zyx/?/?/1 -> NULL
+fetched: /xyz/zyx/?/?/1 -> <undecoded>
 output row: [1]
 
 query T
@@ -1082,13 +1082,13 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /xyz/xyz_pkey/1 -> NULL
+fetched: /xyz/xyz_pkey/1 -> <undecoded>
 fetched: /xyz/xyz_pkey/1/y -> 2
 fetched: /xyz/xyz_pkey/1/z -> 3.0
-fetched: /xyz/xyz_pkey/4 -> NULL
+fetched: /xyz/xyz_pkey/4 -> <undecoded>
 fetched: /xyz/xyz_pkey/4/y -> 5
 fetched: /xyz/xyz_pkey/4/z -> 6.0
-fetched: /xyz/xyz_pkey/7 -> NULL
+fetched: /xyz/xyz_pkey/7 -> <undecoded>
 fetched: /xyz/xyz_pkey/7/z -> 8.0
 output row: [9 4.5 6.33333333333333]
 
diff --git a/pkg/sql/opt/exec/execbuilder/testdata/ddl b/pkg/sql/opt/exec/execbuilder/testdata/ddl
index 86753e91474f..10842170d161 100644
--- a/pkg/sql/opt/exec/execbuilder/testdata/ddl
+++ b/pkg/sql/opt/exec/execbuilder/testdata/ddl
@@ -137,7 +137,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/t_pkey/1 -> NULL
+fetched: /t/t_pkey/1 -> <undecoded>
 fetched: /t/t_pkey/1/b -> 1
 output row: [1 1]
 
@@ -163,7 +163,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/foo/1/1 -> NULL
+fetched: /t/foo/1/1 -> <undecoded>
 output row: [1 1]
 
 statement ok
@@ -177,8 +177,8 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/foo/1/1 -> NULL
-fetched: /t/foo/1/2 -> NULL
+fetched: /t/foo/1/1 -> <undecoded>
+fetched: /t/foo/1/2 -> <undecoded>
 output row: [1 1]
 output row: [2 1]
 
@@ -213,8 +213,8 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/b_desc/?/2 -> NULL
-fetched: /t/b_desc/?/1 -> NULL
+fetched: /t/b_desc/?/2 -> <undecoded>
+fetched: /t/b_desc/?/1 -> <undecoded>
 fetched: /t/t_pkey/1/b/c -> /1/1
 fetched: /t/t_pkey/2/b/c -> /2/2
 output row: [1 1 1]
diff --git a/pkg/sql/opt/exec/execbuilder/testdata/insert b/pkg/sql/opt/exec/execbuilder/testdata/insert
index e6a31b806566..4dccd1721921 100644
--- a/pkg/sql/opt/exec/execbuilder/testdata/insert
+++ b/pkg/sql/opt/exec/execbuilder/testdata/insert
@@ -31,19 +31,19 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /kv/kv_pkey/'A' -> NULL
-fetched: /kv/kv_pkey/'a' -> NULL
+fetched: /kv/kv_pkey/'A' -> <undecoded>
+fetched: /kv/kv_pkey/'a' -> <undecoded>
 fetched: /kv/kv_pkey/'a'/v -> 'b'
-fetched: /kv/kv_pkey/'c' -> NULL
+fetched: /kv/kv_pkey/'c' -> <undecoded>
 fetched: /kv/kv_pkey/'c'/v -> 'd'
-fetched: /kv/kv_pkey/'e' -> NULL
+fetched: /kv/kv_pkey/'e' -> <undecoded>
 fetched: /kv/kv_pkey/'e'/v -> 'f'
-fetched: /kv/kv_pkey/'g' -> NULL
+fetched: /kv/kv_pkey/'g' -> <undecoded>
 fetched: /kv/kv_pkey/'g'/v -> ''
-fetched: /kv/kv_pkey/'nil1' -> NULL
-fetched: /kv/kv_pkey/'nil2' -> NULL
-fetched: /kv/kv_pkey/'nil3' -> NULL
-fetched: /kv/kv_pkey/'nil4' -> NULL
+fetched: /kv/kv_pkey/'nil1' -> <undecoded>
+fetched: /kv/kv_pkey/'nil2' -> <undecoded>
+fetched: /kv/kv_pkey/'nil3' -> <undecoded>
+fetched: /kv/kv_pkey/'nil4' -> <undecoded>
 output row: ['A' NULL]
 output row: ['a' 'b']
 output row: ['c' 'd']
@@ -92,19 +92,19 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /kv/kv_pkey/'A' -> NULL
-fetched: /kv/kv_pkey/'a' -> NULL
+fetched: /kv/kv_pkey/'A' -> <undecoded>
+fetched: /kv/kv_pkey/'a' -> <undecoded>
 fetched: /kv/kv_pkey/'a'/v -> 'b'
-fetched: /kv/kv_pkey/'c' -> NULL
+fetched: /kv/kv_pkey/'c' -> <undecoded>
 fetched: /kv/kv_pkey/'c'/v -> 'd'
-fetched: /kv/kv_pkey/'e' -> NULL
+fetched: /kv/kv_pkey/'e' -> <undecoded>
 fetched: /kv/kv_pkey/'e'/v -> 'f'
-fetched: /kv/kv_pkey/'g' -> NULL
+fetched: /kv/kv_pkey/'g' -> <undecoded>
 fetched: /kv/kv_pkey/'g'/v -> ''
-fetched: /kv/kv_pkey/'nil1' -> NULL
-fetched: /kv/kv_pkey/'nil2' -> NULL
-fetched: /kv/kv_pkey/'nil3' -> NULL
-fetched: /kv/kv_pkey/'nil4' -> NULL
+fetched: /kv/kv_pkey/'nil1' -> <undecoded>
+fetched: /kv/kv_pkey/'nil2' -> <undecoded>
+fetched: /kv/kv_pkey/'nil3' -> <undecoded>
+fetched: /kv/kv_pkey/'nil4' -> <undecoded>
 output row: ['A' NULL]
 output row: ['a' 'b']
 output row: ['c' 'd']
@@ -153,21 +153,21 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /kv/kv_pkey/'A' -> NULL
-fetched: /kv/kv_pkey/'a' -> NULL
+fetched: /kv/kv_pkey/'A' -> <undecoded>
+fetched: /kv/kv_pkey/'a' -> <undecoded>
 fetched: /kv/kv_pkey/'a'/v -> 'b'
-fetched: /kv/kv_pkey/'c' -> NULL
+fetched: /kv/kv_pkey/'c' -> <undecoded>
 fetched: /kv/kv_pkey/'c'/v -> 'd'
-fetched: /kv/kv_pkey/'e' -> NULL
+fetched: /kv/kv_pkey/'e' -> <undecoded>
 fetched: /kv/kv_pkey/'e'/v -> 'f'
-fetched: /kv/kv_pkey/'f' -> NULL
+fetched: /kv/kv_pkey/'f' -> <undecoded>
 fetched: /kv/kv_pkey/'f'/v -> 'g'
-fetched: /kv/kv_pkey/'g' -> NULL
+fetched: /kv/kv_pkey/'g' -> <undecoded>
 fetched: /kv/kv_pkey/'g'/v -> ''
-fetched: /kv/kv_pkey/'nil1' -> NULL
-fetched: /kv/kv_pkey/'nil2' -> NULL
-fetched: /kv/kv_pkey/'nil3' -> NULL
-fetched: /kv/kv_pkey/'nil4' -> NULL
+fetched: /kv/kv_pkey/'nil1' -> <undecoded>
+fetched: /kv/kv_pkey/'nil2' -> <undecoded>
+fetched: /kv/kv_pkey/'nil3' -> <undecoded>
+fetched: /kv/kv_pkey/'nil4' -> <undecoded>
 output row: ['A' NULL]
 output row: ['a' 'b']
 output row: ['c' 'd']
@@ -219,21 +219,21 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /kv/kv_pkey/'A' -> NULL
-fetched: /kv/kv_pkey/'a' -> NULL
+fetched: /kv/kv_pkey/'A' -> <undecoded>
+fetched: /kv/kv_pkey/'a' -> <undecoded>
 fetched: /kv/kv_pkey/'a'/v -> 'b'
-fetched: /kv/kv_pkey/'c' -> NULL
+fetched: /kv/kv_pkey/'c' -> <undecoded>
 fetched: /kv/kv_pkey/'c'/v -> 'd'
-fetched: /kv/kv_pkey/'e' -> NULL
+fetched: /kv/kv_pkey/'e' -> <undecoded>
 fetched: /kv/kv_pkey/'e'/v -> 'f'
-fetched: /kv/kv_pkey/'f' -> NULL
+fetched: /kv/kv_pkey/'f' -> <undecoded>
 fetched: /kv/kv_pkey/'f'/v -> 'g'
-fetched: /kv/kv_pkey/'g' -> NULL
+fetched: /kv/kv_pkey/'g' -> <undecoded>
 fetched: /kv/kv_pkey/'g'/v -> ''
-fetched: /kv/kv_pkey/'nil1' -> NULL
-fetched: /kv/kv_pkey/'nil2' -> NULL
-fetched: /kv/kv_pkey/'nil3' -> NULL
-fetched: /kv/kv_pkey/'nil4' -> NULL
+fetched: /kv/kv_pkey/'nil1' -> <undecoded>
+fetched: /kv/kv_pkey/'nil2' -> <undecoded>
+fetched: /kv/kv_pkey/'nil3' -> <undecoded>
+fetched: /kv/kv_pkey/'nil4' -> <undecoded>
 output row: ['A' NULL]
 output row: ['a' 'b']
 output row: ['c' 'd']
@@ -292,7 +292,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /kv5/a/NULL/'a' -> NULL
+fetched: /kv5/a/NULL/'a' -> <undecoded>
 output row: ['a' NULL]
 
 statement ok
diff --git a/pkg/sql/opt/exec/execbuilder/testdata/orderby b/pkg/sql/opt/exec/execbuilder/testdata/orderby
index 2f746f3e6c1e..d6efd042a732 100644
--- a/pkg/sql/opt/exec/execbuilder/testdata/orderby
+++ b/pkg/sql/opt/exec/execbuilder/testdata/orderby
@@ -302,9 +302,9 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /abc/abc_pkey/1/2/3 -> NULL
+fetched: /abc/abc_pkey/1/2/3 -> <undecoded>
 fetched: /abc/abc_pkey/1/2/3/d -> 'one'
-fetched: /abc/abc_pkey/4/5/6 -> NULL
+fetched: /abc/abc_pkey/4/5/6 -> <undecoded>
 fetched: /abc/abc_pkey/4/5/6/d -> 'Two'
 output row: [1 2 3 'one']
 output row: [4 5 6 'Two']
@@ -317,8 +317,8 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /abc/ba/2/1/? -> NULL
-fetched: /abc/ba/5/4/? -> NULL
+fetched: /abc/ba/2/1/? -> <undecoded>
+fetched: /abc/ba/5/4/? -> <undecoded>
 output row: [1 2]
 output row: [4 5]
 
@@ -490,10 +490,10 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /abc/abc_pkey/4/?/? -> NULL
-fetched: /abc/abc_pkey/4/?/? -> NULL
-fetched: /abc/abc_pkey/1/?/? -> NULL
-fetched: /abc/abc_pkey/1/?/? -> NULL
+fetched: /abc/abc_pkey/4/?/? -> <undecoded>
+fetched: /abc/abc_pkey/4/?/? -> <undecoded>
+fetched: /abc/abc_pkey/1/?/? -> <undecoded>
+fetched: /abc/abc_pkey/1/?/? -> <undecoded>
 output row: [4]
 output row: [1]
 
diff --git a/pkg/sql/opt/exec/execbuilder/testdata/secondary_index_column_families_nonmetamorphic b/pkg/sql/opt/exec/execbuilder/testdata/secondary_index_column_families_nonmetamorphic
index b1757917cd17..0b444422d03f 100644
--- a/pkg/sql/opt/exec/execbuilder/testdata/secondary_index_column_families_nonmetamorphic
+++ b/pkg/sql/opt/exec/execbuilder/testdata/secondary_index_column_families_nonmetamorphic
@@ -59,7 +59,7 @@ query T
 SELECT message FROM [SHOW KV TRACE FOR SESSION] WHERE
 message LIKE 'fetched: /t1/nonuniqueidx/%'
 ----
-fetched: /t1/nonuniqueidx/1/? -> NULL
+fetched: /t1/nonuniqueidx/1/? -> <undecoded>
 
 query I
 SET TRACING=on,kv,results;
@@ -85,7 +85,7 @@ query T
 SELECT message FROM [SHOW KV TRACE FOR SESSION] WHERE
 message LIKE 'fetched: /t1/nonuniqueidxstoring/%'
 ----
-fetched: /t1/nonuniqueidxstoring/1/1 -> NULL
+fetched: /t1/nonuniqueidxstoring/1/1 -> <undecoded>
 fetched: /t1/nonuniqueidxstoring/1/1/z -> /1
 fetched: /t1/nonuniqueidxstoring/1/1/a/b -> /1/1
 
@@ -319,11 +319,11 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WHERE
 message LIKE 'fetched%'
 ORDER BY message
 ----
-fetched: /t/i/2/1 -> NULL
+fetched: /t/i/2/1 -> <undecoded>
 fetched: /t/i/2/1/w -> /3
-fetched: /t/i/5/4 -> NULL
+fetched: /t/i/5/4 -> <undecoded>
 fetched: /t/i/5/4/z -> /6
-fetched: /t/i/9/8 -> NULL
+fetched: /t/i/9/8 -> <undecoded>
 
 statement ok
 DROP TABLE IF EXISTS t;
diff --git a/pkg/sql/opt/exec/execbuilder/testdata/select b/pkg/sql/opt/exec/execbuilder/testdata/select
index 8c25a35d8403..0d9da29764aa 100644
--- a/pkg/sql/opt/exec/execbuilder/testdata/select
+++ b/pkg/sql/opt/exec/execbuilder/testdata/select
@@ -609,8 +609,8 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/b_idx/NULL/2 -> NULL
-fetched: /t/b_idx/NULL/3 -> NULL
+fetched: /t/b_idx/NULL/2 -> <undecoded>
+fetched: /t/b_idx/NULL/3 -> <undecoded>
 fetched: /t/b_idx/2/1/c/d -> /3/4
 output row: [2 NULL NULL NULL]
 output row: [3 NULL NULL NULL]
@@ -826,7 +826,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /dt/dt_pkey/'2015-08-25 04:45:45.53453' -> NULL
+fetched: /dt/dt_pkey/'2015-08-25 04:45:45.53453' -> <undecoded>
 fetched: /dt/dt_pkey/'2015-08-25 04:45:45.53453'/b -> '2015-08-25'
 fetched: /dt/dt_pkey/'2015-08-25 04:45:45.53453'/c -> '02:45:02.234'
 output row: ['2015-08-25 04:45:45.53453' '2015-08-25' '02:45:02.234']
@@ -947,8 +947,8 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /c/b_idx/NULL/2 -> NULL
-fetched: /c/b_idx/NULL/3 -> NULL
+fetched: /c/b_idx/NULL/2 -> <undecoded>
+fetched: /c/b_idx/NULL/3 -> <undecoded>
 fetched: /c/b_idx/0.4/1/b -> /0.40
 output row: [2 NULL]
 output row: [3 NULL]
diff --git a/pkg/sql/opt/exec/execbuilder/testdata/select_index b/pkg/sql/opt/exec/execbuilder/testdata/select_index
index 886850993bf3..7764cfaa8626 100644
--- a/pkg/sql/opt/exec/execbuilder/testdata/select_index
+++ b/pkg/sql/opt/exec/execbuilder/testdata/select_index
@@ -29,7 +29,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/t_pkey/2/'two' -> NULL
+fetched: /t/t_pkey/2/'two' -> <undecoded>
 fetched: /t/t_pkey/2/'two'/c -> 22
 fetched: /t/t_pkey/2/'two'/d -> 'bar'
 output row: [2 'two' 22 'bar']
@@ -42,10 +42,10 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/t_pkey/1/'one' -> NULL
+fetched: /t/t_pkey/1/'one' -> <undecoded>
 fetched: /t/t_pkey/1/'one'/c -> 11
 fetched: /t/t_pkey/1/'one'/d -> 'foo'
-fetched: /t/t_pkey/3/'three' -> NULL
+fetched: /t/t_pkey/3/'three' -> <undecoded>
 fetched: /t/t_pkey/3/'three'/c -> 33
 fetched: /t/t_pkey/3/'three'/d -> 'blah'
 output row: [1 'one' 11 'foo']
@@ -59,8 +59,8 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/dc/'bar'/22/2/'two' -> NULL
-fetched: /t/dc/'foo'/11/1/'one' -> NULL
+fetched: /t/dc/'bar'/22/2/'two' -> <undecoded>
+fetched: /t/dc/'foo'/11/1/'one' -> <undecoded>
 output row: [2 'two' 22 'bar']
 output row: [1 'one' 11 'foo']
 
@@ -72,8 +72,8 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/dc/'bar'/22/2/'two' -> NULL
-fetched: /t/dc/'foo'/11/1/'one' -> NULL
+fetched: /t/dc/'bar'/22/2/'two' -> <undecoded>
+fetched: /t/dc/'foo'/11/1/'one' -> <undecoded>
 output row: [2 'two' 22 'bar']
 output row: [1 'one' 11 'foo']
 
@@ -85,7 +85,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/dc/'foo'/11/1/'one' -> NULL
+fetched: /t/dc/'foo'/11/1/'one' -> <undecoded>
 output row: [1 'one' 11 'foo']
 
 statement ok
@@ -96,7 +96,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/t_pkey/1/'one' -> NULL
+fetched: /t/t_pkey/1/'one' -> <undecoded>
 fetched: /t/t_pkey/1/'one'/c -> 11
 fetched: /t/t_pkey/1/'one'/d -> 'foo'
 output row: [1 'one' 11 'foo']
@@ -109,10 +109,10 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/t_pkey/1/'one' -> NULL
+fetched: /t/t_pkey/1/'one' -> <undecoded>
 fetched: /t/t_pkey/1/'one'/c -> 11
 fetched: /t/t_pkey/1/'one'/d -> 'foo'
-fetched: /t/t_pkey/2/'two' -> NULL
+fetched: /t/t_pkey/2/'two' -> <undecoded>
 fetched: /t/t_pkey/2/'two'/c -> 22
 fetched: /t/t_pkey/2/'two'/d -> 'bar'
 output row: [1 'one' 11 'foo']
@@ -126,8 +126,8 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/bc/'three'/?/3 -> NULL
-fetched: /t/bc/'two'/?/2 -> NULL
+fetched: /t/bc/'three'/?/3 -> <undecoded>
+fetched: /t/bc/'two'/?/2 -> <undecoded>
 output row: [3 'three']
 output row: [2 'two']
 
@@ -139,7 +139,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/dc/'bar'/22/2/'two' -> NULL
+fetched: /t/dc/'bar'/22/2/'two' -> <undecoded>
 output row: [2 'two' 22 'bar']
 
 statement ok
@@ -150,13 +150,13 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/t_pkey/1/'one' -> NULL
+fetched: /t/t_pkey/1/'one' -> <undecoded>
 fetched: /t/t_pkey/1/'one'/c -> 11
 fetched: /t/t_pkey/1/'one'/d -> 'foo'
-fetched: /t/t_pkey/2/'two' -> NULL
+fetched: /t/t_pkey/2/'two' -> <undecoded>
 fetched: /t/t_pkey/2/'two'/c -> 22
 fetched: /t/t_pkey/2/'two'/d -> 'bar'
-fetched: /t/t_pkey/3/'three' -> NULL
+fetched: /t/t_pkey/3/'three' -> <undecoded>
 fetched: /t/t_pkey/3/'three'/c -> 33
 fetched: /t/t_pkey/3/'three'/d -> 'blah'
 output row: [2 'two' 22 'bar']
@@ -170,9 +170,9 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/a_desc/3/? -> NULL
-fetched: /t/a_desc/2/? -> NULL
-fetched: /t/a_desc/1/? -> NULL
+fetched: /t/a_desc/3/? -> <undecoded>
+fetched: /t/a_desc/2/? -> <undecoded>
+fetched: /t/a_desc/1/? -> <undecoded>
 output row: [3]
 output row: [2]
 output row: [1]
@@ -186,8 +186,8 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/a_desc/3/? -> NULL
-fetched: /t/a_desc/2/? -> NULL
+fetched: /t/a_desc/3/? -> <undecoded>
+fetched: /t/a_desc/2/? -> <undecoded>
 output row: [3]
 output row: [2]
 
@@ -249,7 +249,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/t_pkey/1/'c' -> NULL
+fetched: /t/t_pkey/1/'c' -> <undecoded>
 output row: [1 'c' NULL NULL]
 
 statement ok
@@ -260,7 +260,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/t_pkey/1/'c' -> NULL
+fetched: /t/t_pkey/1/'c' -> <undecoded>
 output row: [1 'c' NULL NULL]
 
 statement ok
@@ -288,7 +288,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/t_pkey/1/'b' -> NULL
+fetched: /t/t_pkey/1/'b' -> <undecoded>
 output row: [1 'b' NULL NULL]
 
 statement ok
@@ -312,7 +312,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/ab/3/4 -> NULL
+fetched: /t/ab/3/4 -> <undecoded>
 output row: [3 4]
 
 statement ok
@@ -323,7 +323,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/ab/3/4 -> NULL
+fetched: /t/ab/3/4 -> <undecoded>
 output row: [3 4]
 
 statement ok
@@ -334,8 +334,8 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/ab/3/4 -> NULL
-fetched: /t/ab/5/6 -> NULL
+fetched: /t/ab/3/4 -> <undecoded>
+fetched: /t/ab/5/6 -> <undecoded>
 output row: [3 4]
 output row: [5 6]
 
@@ -347,8 +347,8 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/ab/1/2 -> NULL
-fetched: /t/ab/3/4 -> NULL
+fetched: /t/ab/1/2 -> <undecoded>
+fetched: /t/ab/3/4 -> <undecoded>
 output row: [1 2]
 output row: [3 4]
 
@@ -360,8 +360,8 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/ab/1/2 -> NULL
-fetched: /t/ab/3/4 -> NULL
+fetched: /t/ab/1/2 -> <undecoded>
+fetched: /t/ab/3/4 -> <undecoded>
 output row: [1 2]
 output row: [3 4]
 
@@ -373,8 +373,8 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/ab/1/2 -> NULL
-fetched: /t/ab/3/4 -> NULL
+fetched: /t/ab/1/2 -> <undecoded>
+fetched: /t/ab/3/4 -> <undecoded>
 output row: [1 2]
 output row: [3 4]
 
@@ -386,8 +386,8 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/ab/3/4 -> NULL
-fetched: /t/ab/5/6 -> NULL
+fetched: /t/ab/3/4 -> <undecoded>
+fetched: /t/ab/5/6 -> <undecoded>
 output row: [3 4]
 output row: [5 6]
 
@@ -399,8 +399,8 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/ab/3/4 -> NULL
-fetched: /t/ab/5/6 -> NULL
+fetched: /t/ab/3/4 -> <undecoded>
+fetched: /t/ab/5/6 -> <undecoded>
 output row: [3 4]
 output row: [5 6]
 
@@ -412,8 +412,8 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/ab/3/4 -> NULL
-fetched: /t/ab/5/6 -> NULL
+fetched: /t/ab/3/4 -> <undecoded>
+fetched: /t/ab/5/6 -> <undecoded>
 output row: [3 4]
 output row: [5 6]
 
@@ -425,8 +425,8 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/ab/1/2 -> NULL
-fetched: /t/ab/5/6 -> NULL
+fetched: /t/ab/1/2 -> <undecoded>
+fetched: /t/ab/5/6 -> <undecoded>
 output row: [1 2]
 output row: [5 6]
 
@@ -438,7 +438,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t/ab/3/4 -> NULL
+fetched: /t/ab/3/4 -> <undecoded>
 output row: [3 4]
 
 query T
@@ -1318,8 +1318,8 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /noncover/b/?/1 -> NULL
-fetched: /noncover/noncover_pkey/1 -> NULL
+fetched: /noncover/b/?/1 -> <undecoded>
+fetched: /noncover/noncover_pkey/1 -> <undecoded>
 fetched: /noncover/noncover_pkey/1/b -> 2
 fetched: /noncover/noncover_pkey/1/c -> 3
 fetched: /noncover/noncover_pkey/1/d -> 4
@@ -1356,7 +1356,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
 fetched: /noncover/c/? -> /5
-fetched: /noncover/noncover_pkey/5 -> NULL
+fetched: /noncover/noncover_pkey/5 -> <undecoded>
 fetched: /noncover/noncover_pkey/5/b -> 6
 fetched: /noncover/noncover_pkey/5/c -> 7
 fetched: /noncover/noncover_pkey/5/d -> 8
@@ -1599,10 +1599,10 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t2/bc/2/1/4 -> NULL
-fetched: /t2/bc/2/2/5 -> NULL
-fetched: /t2/bc/2/3/6 -> NULL
-fetched: /t2/t2_pkey/5 -> NULL
+fetched: /t2/bc/2/1/4 -> <undecoded>
+fetched: /t2/bc/2/2/5 -> <undecoded>
+fetched: /t2/bc/2/3/6 -> <undecoded>
+fetched: /t2/t2_pkey/5 -> <undecoded>
 fetched: /t2/t2_pkey/5/b -> 2
 fetched: /t2/t2_pkey/5/c -> 2
 fetched: /t2/t2_pkey/5/s -> '22'
@@ -1635,13 +1635,13 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t2/bc/?/?/4 -> NULL
-fetched: /t2/bc/?/?/6 -> NULL
-fetched: /t2/t2_pkey/4 -> NULL
+fetched: /t2/bc/?/?/4 -> <undecoded>
+fetched: /t2/bc/?/?/6 -> <undecoded>
+fetched: /t2/t2_pkey/4 -> <undecoded>
 fetched: /t2/t2_pkey/4/b -> 2
 fetched: /t2/t2_pkey/4/c -> 1
 fetched: /t2/t2_pkey/4/s -> '21'
-fetched: /t2/t2_pkey/6 -> NULL
+fetched: /t2/t2_pkey/6 -> <undecoded>
 fetched: /t2/t2_pkey/6/b -> 2
 fetched: /t2/t2_pkey/6/c -> 3
 fetched: /t2/t2_pkey/6/s -> '23'
@@ -1657,13 +1657,13 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t2/bc/?/?/4 -> NULL
-fetched: /t2/bc/?/?/6 -> NULL
-fetched: /t2/t2_pkey/4 -> NULL
+fetched: /t2/bc/?/?/4 -> <undecoded>
+fetched: /t2/bc/?/?/6 -> <undecoded>
+fetched: /t2/t2_pkey/4 -> <undecoded>
 fetched: /t2/t2_pkey/4/b -> 2
 fetched: /t2/t2_pkey/4/c -> 1
 fetched: /t2/t2_pkey/4/s -> '21'
-fetched: /t2/t2_pkey/6 -> NULL
+fetched: /t2/t2_pkey/6 -> <undecoded>
 fetched: /t2/t2_pkey/6/b -> 2
 fetched: /t2/t2_pkey/6/c -> 3
 fetched: /t2/t2_pkey/6/s -> '23'
@@ -1679,39 +1679,39 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t2/t2_pkey/1 -> NULL
+fetched: /t2/t2_pkey/1 -> <undecoded>
 fetched: /t2/t2_pkey/1/b -> 1
 fetched: /t2/t2_pkey/1/c -> 1
 fetched: /t2/t2_pkey/1/s -> '11'
-fetched: /t2/t2_pkey/2 -> NULL
+fetched: /t2/t2_pkey/2 -> <undecoded>
 fetched: /t2/t2_pkey/2/b -> 1
 fetched: /t2/t2_pkey/2/c -> 2
 fetched: /t2/t2_pkey/2/s -> '12'
-fetched: /t2/t2_pkey/3 -> NULL
+fetched: /t2/t2_pkey/3 -> <undecoded>
 fetched: /t2/t2_pkey/3/b -> 1
 fetched: /t2/t2_pkey/3/c -> 3
 fetched: /t2/t2_pkey/3/s -> '13'
-fetched: /t2/t2_pkey/4 -> NULL
+fetched: /t2/t2_pkey/4 -> <undecoded>
 fetched: /t2/t2_pkey/4/b -> 2
 fetched: /t2/t2_pkey/4/c -> 1
 fetched: /t2/t2_pkey/4/s -> '21'
-fetched: /t2/t2_pkey/5 -> NULL
+fetched: /t2/t2_pkey/5 -> <undecoded>
 fetched: /t2/t2_pkey/5/b -> 2
 fetched: /t2/t2_pkey/5/c -> 2
 fetched: /t2/t2_pkey/5/s -> '22'
-fetched: /t2/t2_pkey/6 -> NULL
+fetched: /t2/t2_pkey/6 -> <undecoded>
 fetched: /t2/t2_pkey/6/b -> 2
 fetched: /t2/t2_pkey/6/c -> 3
 fetched: /t2/t2_pkey/6/s -> '23'
-fetched: /t2/t2_pkey/7 -> NULL
+fetched: /t2/t2_pkey/7 -> <undecoded>
 fetched: /t2/t2_pkey/7/b -> 3
 fetched: /t2/t2_pkey/7/c -> 1
 fetched: /t2/t2_pkey/7/s -> '31'
-fetched: /t2/t2_pkey/8 -> NULL
+fetched: /t2/t2_pkey/8 -> <undecoded>
 fetched: /t2/t2_pkey/8/b -> 3
 fetched: /t2/t2_pkey/8/c -> 2
 fetched: /t2/t2_pkey/8/s -> '32'
-fetched: /t2/t2_pkey/9 -> NULL
+fetched: /t2/t2_pkey/9 -> <undecoded>
 fetched: /t2/t2_pkey/9/b -> 3
 fetched: /t2/t2_pkey/9/c -> 3
 fetched: /t2/t2_pkey/9/s -> '33'
@@ -1806,7 +1806,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t4/t4_pkey/?/? -> NULL
+fetched: /t4/t4_pkey/?/? -> <undecoded>
 fetched: /t4/t4_pkey/?/?/c -> 30
 output row: [30]
 
@@ -1830,7 +1830,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /t4/t4_pkey/?/? -> NULL
+fetched: /t4/t4_pkey/?/? -> <undecoded>
 fetched: /t4/t4_pkey/?/?/d -> 40
 output row: [40]
 
diff --git a/pkg/sql/opt/exec/execbuilder/testdata/update b/pkg/sql/opt/exec/execbuilder/testdata/update
index f837456c71bc..2dbc8332e4f4 100644
--- a/pkg/sql/opt/exec/execbuilder/testdata/update
+++ b/pkg/sql/opt/exec/execbuilder/testdata/update
@@ -20,13 +20,13 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /kv2/kv2_pkey/'a' -> NULL
+fetched: /kv2/kv2_pkey/'a' -> <undecoded>
 fetched: /kv2/kv2_pkey/'a'/v -> 'b'
-fetched: /kv2/kv2_pkey/'c' -> NULL
+fetched: /kv2/kv2_pkey/'c' -> <undecoded>
 fetched: /kv2/kv2_pkey/'c'/v -> 'd'
-fetched: /kv2/kv2_pkey/'e' -> NULL
+fetched: /kv2/kv2_pkey/'e' -> <undecoded>
 fetched: /kv2/kv2_pkey/'e'/v -> 'f'
-fetched: /kv2/kv2_pkey/'f' -> NULL
+fetched: /kv2/kv2_pkey/'f' -> <undecoded>
 fetched: /kv2/kv2_pkey/'f'/v -> 'g'
 output row: ['a' 'b']
 output row: ['c' 'd']
@@ -61,13 +61,13 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /kv2/kv2_pkey/'a' -> NULL
+fetched: /kv2/kv2_pkey/'a' -> <undecoded>
 fetched: /kv2/kv2_pkey/'a'/v -> 'b'
-fetched: /kv2/kv2_pkey/'c' -> NULL
+fetched: /kv2/kv2_pkey/'c' -> <undecoded>
 fetched: /kv2/kv2_pkey/'c'/v -> 'd'
-fetched: /kv2/kv2_pkey/'e' -> NULL
+fetched: /kv2/kv2_pkey/'e' -> <undecoded>
 fetched: /kv2/kv2_pkey/'e'/v -> 'f'
-fetched: /kv2/kv2_pkey/'f' -> NULL
+fetched: /kv2/kv2_pkey/'f' -> <undecoded>
 fetched: /kv2/kv2_pkey/'f'/v -> 'g'
 output row: ['a' 'b']
 output row: ['c' 'd']
@@ -301,7 +301,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
  WHERE message LIKE 'fetched:%' OR message LIKE 'output row%'
  ORDER BY message LIKE 'fetched:%' DESC, ordinality ASC
 ----
-fetched: /pks/pks_pkey/2/2 -> NULL
+fetched: /pks/pks_pkey/2/2 -> <undecoded>
 fetched: /pks/pks_pkey/2/2/v -> 3
 output row: [2 2 3]
 
diff --git a/pkg/sql/opt/exec/execbuilder/testdata/update_nonmetamorphic b/pkg/sql/opt/exec/execbuilder/testdata/update_nonmetamorphic
index c7059feb1373..fa2ef182c9ca 100644
--- a/pkg/sql/opt/exec/execbuilder/testdata/update_nonmetamorphic
+++ b/pkg/sql/opt/exec/execbuilder/testdata/update_nonmetamorphic
@@ -44,8 +44,8 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION]
  WHERE operation != 'dist sender send'
 ----
 Scan /Table/56/{1-2}
-fetched: /tu/tu_pkey/1 -> NULL
-fetched: /tu/tu_pkey/1 -> NULL
+fetched: /tu/tu_pkey/1 -> <undecoded>
+fetched: /tu/tu_pkey/1 -> <undecoded>
 fetched: /tu/tu_pkey/1/c/d -> /3/4
 Put /Table/56/1/1/2/1 -> /TUPLE/3:3:Int/4/1:4:Int/4
 fast path completed
@@ -59,7 +59,7 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION]
  WHERE operation != 'dist sender send'
 ----
 Scan /Table/56/{1-2}
-fetched: /tu/tu_pkey/1 -> NULL
+fetched: /tu/tu_pkey/1 -> <undecoded>
 fetched: /tu/tu_pkey/1/b -> 2
 fetched: /tu/tu_pkey/1/c/d -> /4/4
 Del /Table/56/1/1/1/1
diff --git a/pkg/sql/opt/exec/execbuilder/testdata/window b/pkg/sql/opt/exec/execbuilder/testdata/window
index 6b70745ecb0a..46fa5118e261 100644
--- a/pkg/sql/opt/exec/execbuilder/testdata/window
+++ b/pkg/sql/opt/exec/execbuilder/testdata/window
@@ -33,21 +33,21 @@ SELECT message FROM [SHOW KV TRACE FOR SESSION] WITH ORDINALITY
 ----
 fetched: /kv/kv_pkey/1/v -> /2
 fetched: /kv/kv_pkey/1/d -> 1
-fetched: /kv/kv_pkey/1 -> NULL
+fetched: /kv/kv_pkey/1 -> <undecoded>
 fetched: /kv/kv_pkey/3/v -> /4
 fetched: /kv/kv_pkey/3/d -> 8
-fetched: /kv/kv_pkey/3 -> NULL
-fetched: /kv/kv_pkey/5 -> NULL
+fetched: /kv/kv_pkey/3 -> <undecoded>
+fetched: /kv/kv_pkey/5 -> <undecoded>
 fetched: /kv/kv_pkey/5/d -> -321
 fetched: /kv/kv_pkey/6/v -> /2
 fetched: /kv/kv_pkey/6/d -> 4.4
-fetched: /kv/kv_pkey/6 -> NULL
+fetched: /kv/kv_pkey/6 -> <undecoded>
 fetched: /kv/kv_pkey/7/v -> /2
 fetched: /kv/kv_pkey/7/d -> 7.9
-fetched: /kv/kv_pkey/7 -> NULL
+fetched: /kv/kv_pkey/7 -> <undecoded>
 fetched: /kv/kv_pkey/8/v -> /4
 fetched: /kv/kv_pkey/8/d -> 3
-fetched: /kv/kv_pkey/8 -> NULL
+fetched: /kv/kv_pkey/8 -> <undecoded>
 output row: [5 NULL]
 output row: [1 3.4501207708330056852]
 output row: [6 3.4501207708330056852]
diff --git a/pkg/sql/row/fetcher.go b/pkg/sql/row/fetcher.go
index 0a34de20cc01..e3114a33ba69 100644
--- a/pkg/sql/row/fetcher.go
+++ b/pkg/sql/row/fetcher.go
@@ -869,7 +869,7 @@ func (rf *Fetcher) processKV(
 	if table.neededCols.Empty() {
 		// We don't need to decode any values.
 		if rf.traceKV {
-			prettyValue = tree.DNull.String()
+			prettyValue = "<undecoded>"
 		}
 		return prettyKey, prettyValue, nil
 	}
@@ -977,7 +977,7 @@ func (rf *Fetcher) processKV(
 	}
 
 	if rf.traceKV && prettyValue == "" {
-		prettyValue = tree.DNull.String()
+		prettyValue = "<undecoded>"
 	}
 
 	return prettyKey, prettyValue, nil
diff --git a/pkg/sql/schema_changer_test.go b/pkg/sql/schema_changer_test.go
index 749df19a5300..09b6bb0a4d7d 100644
--- a/pkg/sql/schema_changer_test.go
+++ b/pkg/sql/schema_changer_test.go
@@ -3792,7 +3792,7 @@ CREATE TABLE d.t (
 	}
 	// Ensure that the decoder sees the old encoding.
 	for indexName, expExplainRow := range map[string]string{
-		"i": "fetched: /t/i/1/11/2 -> NULL",
+		"i": "fetched: /t/i/1/11/2 -> <undecoded>",
 		"u": "fetched: /t/u/1 -> /11/2",
 	} {
 		t.Run("index scan", func(t *testing.T) {