sql: remove redundant DOidWrapper checks

We had many `tree.AsD*` functions which checked whether the given datum
was a DOidWrapper around another datum. Given that we now only support
oid-wrapping on top of `DString` and `DCollatedString`, most of these
functions are redundant and were only introduced due to blind
copy-paste. This commit removes most of them, replacing with an explicit
type cast.

Release note: None

Author: yuzefovich

pkg/ccl/changefeedccl/event_processing.go

@@ -825,7 +825,7 @@ func readOneJSONValue(row cdcevent.Row, colName string) (*tree.DJSON, error) {
 		if d == tree.DNull {
 			return nil
 		}
-		if valJSON, ok = tree.AsDJSON(d); !ok {
+		if valJSON, ok = d.(*tree.DJSON); !ok {
 			return errors.Newf("expected a JSON object, got %s", d.ResolvedType())
 		}
 		return nil

pkg/crosscluster/logical/sql_row_reader.go

@@ -128,7 +128,7 @@ func (r *sqlRowReader) ReadRows(
 			isLocal = true
 		}
 
-		decimal, ok := tree.AsDDecimal(timestamp)
+		decimal, ok := timestamp.(*tree.DDecimal)
 		if !ok {
 			return nil, errors.AssertionFailedf("expected column 1 or 2 to be origin timestamp")
 		}

pkg/multitenant/mtinfo/info.go

@@ -53,11 +53,11 @@ func GetTenantInfoFromSQLRow(
 	if len(row) < 2 || row[1] == tree.DNull {
 		return tid, nil, errors.AssertionFailedf("%v: missing data in info column", tid)
 	}
-	ival, ok := tree.AsDBytes(row[1])
+	ival, ok := row[1].(*tree.DBytes)
 	if !ok {
 		return tid, nil, errors.AssertionFailedf("%v: info: expected bytes, got %T", tid, row[1])
 	}
-	infoBytes := []byte(ival)
+	infoBytes := []byte(*ival)
 	if err := protoutil.Unmarshal(infoBytes, &info.ProtoInfo); err != nil {
 		return tid, nil, errors.NewAssertionErrorWithWrappedErrf(err, "%v: decoding info column", tid)
 	}

pkg/sql/backfill/backfill.go

@@ -522,7 +522,7 @@ func (vih *VectorIndexHelper) ReEncodeVector(
 	}
 	key.PartitionKey = cspann.PartitionKey(tree.MustBeDInt(searcher.PartitionKey()))
 	key.Level = cspann.LeafLevel
-	quantizedVector, ok := tree.AsDBytes(searcher.EncodedVector())
+	quantizedVector, ok := searcher.EncodedVector().(*tree.DBytes)
 	if !ok {
 		return &rowenc.IndexEntry{}, errors.AssertionFailedf("expected encoded vector to be of type DBytes")
 	}

pkg/sql/colexec/colbuilder/execplan.go

@@ -2229,7 +2229,7 @@ func planSelectionOperators(
 				}
 			case treecmp.In, treecmp.NotIn:
 				negate := cmpOp.Symbol == treecmp.NotIn
-				datumTuple, ok := tree.AsDTuple(constArg)
+				datumTuple, ok := constArg.(*tree.DTuple)
 				if !ok || useDefaultCmpOpForIn(datumTuple) {
 					break
 				}
@@ -2882,7 +2882,7 @@ func planProjectionExpr(
 					}
 				case treecmp.In, treecmp.NotIn:
 					negate := cmpProjOp.Symbol == treecmp.NotIn
-					datumTuple, ok := tree.AsDTuple(rConstArg)
+					datumTuple, ok := rConstArg.(*tree.DTuple)
 					if !ok || useDefaultCmpOpForIn(datumTuple) {
 						break
 					}

pkg/sql/crdb_internal.go

@@ -7961,8 +7961,8 @@ CREATE TABLE crdb_internal.cluster_locks (
 		},
 		{
 			populate: genPopulateClusterLocksWithIndex("contended" /* idxColumnName */, func(filters *clusterLocksFilters, idxConstraint tree.Datum) {
-				if contended, ok := tree.AsDBool(idxConstraint); ok {
-					filters.contended = (*bool)(&contended)
+				if contended, ok := idxConstraint.(*tree.DBool); ok {
+					filters.contended = (*bool)(contended)
 				}
 			}),
 		},

pkg/sql/opt/norm/fold_constants_funcs.go

@@ -338,7 +338,7 @@ func (c *CustomFuncs) foldOIDFamilyCast(
 			if err != nil {
 				return nil, false, err
 			}
-			oid, ok := tree.AsDOid(cDatum)
+			oid, ok := cDatum.(*tree.DOid)
 			if !ok {
 				return nil, false, nil
 			}

pkg/sql/paramparse/paramparse.go

@@ -138,15 +138,15 @@ func DatumAsBool(
 	if err != nil {
 		return false, err
 	}
-	b, ok := tree.AsDBool(val)
+	b, ok := val.(*tree.DBool)
 	if !ok {
 		err = pgerror.Newf(pgcode.InvalidParameterValue,
 			"parameter %q requires a Boolean value", name)
 		err = errors.WithDetailf(err,
 			"%s is a %s", value, errors.Safe(val.ResolvedType()))
 		return false, err
 	}
-	return bool(b), nil
+	return bool(*b), nil
 }
 
 // GetSingleBool returns the boolean if the input Datum is a DBool,

pkg/sql/routine.go

@@ -62,7 +62,7 @@ func (d *callNode) startExec(params runParams) error {
 	if res == tree.DNull {
 		return pgerror.New(pgcode.Internal, "procedure returned null record")
 	}
-	tuple, ok := tree.AsDTuple(res)
+	tuple, ok := res.(*tree.DTuple)
 	if !ok {
 		return errors.AssertionFailedf("expected a tuple, got %T", res)
 	}

pkg/sql/rowenc/index_encoding.go

@@ -1651,7 +1651,7 @@ func encodeSecondaryIndexNoFamilies(
 		// Vector index values begin with the quantized and encoded vector. It is
 		// possible that it is not supplied here (e.g. for an index delete).
 		if encVector := vh.QuantizedVecs[index.GetID()]; encVector != nil {
-			encVectorBytes, ok := tree.AsDBytes(encVector)
+			encVectorBytes, ok := encVector.(*tree.DBytes)
 			if !ok {
 				return IndexEntry{}, errors.AssertionFailedf(
 					"unexpected type for vector index value: %T", encVector)