sql: support INSERT with partial UNIQUE WITHOUT INDEX constraints

Uniqueness checks on INSERTs are now performed for partial UNIQUE
WITHOUT INDEX constraints. The semi-join filters in the uniqueness
checks filter out rows that do not satisfy the predicate. Rows on both
sides of the join are filtered. This is required to prevent duplicate
key violations from occurring for rows that do not satisfy the predicate
of the partial unique constraint.

The WithScan and Scan of the uniqueness check now produce all ordinary
table columns, rather than just the PK and unique columns, because
predicates may refer any columns in the table.

Informs #59195

There is no release note because these constraints are gated behind the
experimental_enable_unique_without_index_constraints session variable.

Release note: None

pkg/ccl/logictestccl/testdata/logic_test/regional_by_row

@@ -299,7 +299,7 @@ vectorized: true
 │       │
 │       └── • lookup join (semi)
 │           │ table: regional_by_row_table@primary
-│           │ equality: (lookup_join_const_col_@24, column1) = (crdb_region,pk)
+│           │ equality: (lookup_join_const_col_@22, column1) = (crdb_region,pk)
 │           │ equality cols are key
 │           │ pred: column15 != crdb_region
 │           │
@@ -317,7 +317,7 @@ vectorized: true
 │       │
 │       └── • lookup join (semi)
 │           │ table: regional_by_row_table@regional_by_row_table_b_key
-│           │ equality: (lookup_join_const_col_@36, column4) = (crdb_region,b)
+│           │ equality: (lookup_join_const_col_@37, column4) = (crdb_region,b)
 │           │ equality cols are key
 │           │ pred: (column1 != pk) OR (column15 != crdb_region)
 │           │
@@ -335,7 +335,7 @@ vectorized: true
         │
         └── • lookup join (semi)
             │ table: regional_by_row_table@new_idx
-            │ equality: (lookup_join_const_col_@49, column3, column4) = (crdb_region,a,b)
+            │ equality: (lookup_join_const_col_@52, column3, column4) = (crdb_region,a,b)
             │ equality cols are key
             │ pred: (column1 != pk) OR (column15 != crdb_region)
             │
@@ -385,7 +385,7 @@ vectorized: true
 │       │
 │       └── • lookup join (semi)
 │           │ table: regional_by_row_table@primary
-│           │ equality: (lookup_join_const_col_@35, upsert_pk) = (crdb_region,pk)
+│           │ equality: (lookup_join_const_col_@33, upsert_pk) = (crdb_region,pk)
 │           │ equality cols are key
 │           │ pred: column1 != crdb_region
 │           │
@@ -403,7 +403,7 @@ vectorized: true
 │       │
 │       └── • lookup join (semi)
 │           │ table: regional_by_row_table@regional_by_row_table_b_key
-│           │ equality: (lookup_join_const_col_@47, column5) = (crdb_region,b)
+│           │ equality: (lookup_join_const_col_@48, column5) = (crdb_region,b)
 │           │ equality cols are key
 │           │ pred: (upsert_pk != pk) OR (column1 != crdb_region)
 │           │
@@ -421,7 +421,7 @@ vectorized: true
         │
         └── • lookup join (semi)
             │ table: regional_by_row_table@new_idx
-            │ equality: (lookup_join_const_col_@60, column4, column5) = (crdb_region,a,b)
+            │ equality: (lookup_join_const_col_@63, column4, column5) = (crdb_region,a,b)
             │ equality cols are key
             │ pred: (upsert_pk != pk) OR (column1 != crdb_region)
             │

pkg/sql/logictest/testdata/logic_test/unique

@@ -251,6 +251,49 @@ us-west  foo  1  1
 eu-west  bar  2  2
 
 
+# Insert some non-null data into a table with a partial unique without index
+# constraint.
+statement ok
+INSERT INTO uniq_partial VALUES (1, 1), (1, -1), (2, 2)
+
+# Partial unique constraint violation.
+statement error pgcode 23505 pq: duplicate key value violates unique constraint "unique_a"\nDETAIL: Key \(a\)=\(1\) already exists\.
+INSERT INTO uniq_partial VALUES (1, 3)
+
+# No partial unique constraint violation because b <= 0.
+statement ok
+INSERT INTO uniq_partial VALUES (1, -3)
+
+# Attempt to insert conflicting keys twice in the same statement.
+statement error pgcode 23505 pq: duplicate key value violates unique constraint "unique_a"\nDETAIL: Key \(a\)=\(3\) already exists\.
+INSERT INTO uniq_partial VALUES (3, 3), (3, 4)
+
+# Attempt to insert one conflicting key and one non-conflicting key in the same
+# statement.
+statement error pgcode 23505 pq: duplicate key value violates unique constraint "unique_a"\nDETAIL: Key \(a\)=\(1\) already exists\.
+INSERT INTO uniq_partial VALUES (1, 3), (3, 3)
+
+# Insert some rows with NULL keys.
+statement ok
+INSERT INTO uniq_partial VALUES (NULL, 5), (5, 5), (NULL, 5)
+
+# Insert with non-constant input.
+statement error pgcode 23505 pq: duplicate key value violates unique constraint "unique_a"\nDETAIL: Key \(a\)=\(1\) already exists\.
+INSERT INTO uniq_partial SELECT w, x FROM other
+
+query II colnames,rowsort
+SELECT * FROM uniq_partial
+----
+a     b
+1     1
+1     -1
+1     -3
+2     2
+5     5
+NULL  5
+NULL  5
+
+
 # -- Tests with UPDATE --
 subtest Update