sql: log undecoded values as <undecoded> in tracing

Previously, if the value part of a key-value pair wasn't needed, we
would log it as `NULL`. However, that can be confusing whether an actual
`NULL` value was decoded or not. This commit replaces the undecoded
values with `<undecoded>` reducing the confusion (given that the
likelihood of the value actually being equal to `<undecoded>` is
negligible).

Release note: None

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

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

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]
 

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]

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

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]
 

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;