diff --git a/internal/contentdata/repository.go b/internal/contentdata/repository.go
index 7be8c3bc7..af39e360b 100644
--- a/internal/contentdata/repository.go
+++ b/internal/contentdata/repository.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"database/sql"
 	"fmt"
+	"math/big"
 	"reflect"
 	"strings"
 
@@ -400,7 +401,9 @@ func (r *Repository) AddTableData(ctx context.Context, tx *connection.Tx, projec
 		for _, column := range columns {
 			if value, found := data[column.Name]; found {
 				isTimestampColumn := column.Type == types.TIMESTAMP
+				isBigNumeric := column.Type == types.BIGNUMERIC
 				inputString, isInputString := value.(string)
+				inputBytes, isInputBytes := value.([]uint8)
 
 				if isInputString && isTimestampColumn {
 					parsedTimestamp, err := zetasqlite.TimeFromTimestampValue(inputString)
@@ -411,6 +414,14 @@ func (r *Repository) AddTableData(ctx context.Context, tx *connection.Tx, projec
 					}
 				}
 
+				if isBigNumeric && isInputBytes {
+					parsedString, err := BigNumericFromBytes(inputBytes)
+					if err == nil {
+						values = append(values, parsedString)
+						continue
+					}
+				}
+
 				values = append(values, value)
 			} else {
 				values = append(values, nil)
@@ -425,6 +436,34 @@ func (r *Repository) AddTableData(ctx context.Context, tx *connection.Tx, projec
 	return nil
 }
 
+func BigNumericFromBytes(v []uint8) (string, error) {
+	if len(v) == 0 {
+		return "", fmt.Errorf("invalid input: empty byte array")
+	}
+	bytes := make([]byte, len(v))
+	for i := 0; i < len(v); i++ {
+		bytes[i] = v[len(v)-1-i]
+	}
+	negative := bytes[0]&0x80 != 0
+	n := new(big.Int)
+	if negative {
+		for i := 0; i < len(bytes); i++ {
+			bytes[i] = ^bytes[i]
+		}
+		n.SetBytes(bytes)
+		n.Add(n, big.NewInt(1))
+		n.Neg(n)
+	} else {
+		n.SetBytes(bytes)
+	}
+	scaleFactor := new(big.Rat)
+	scaleFactor.SetString("100000000000000000000000000000000000000")
+	result := new(big.Rat).Quo(new(big.Rat).SetInt(n), scaleFactor).FloatString(10)
+	result = strings.TrimRight(result, "0")
+	result = strings.TrimRight(result, ".")
+	return result, nil
+}
+
 func (r *Repository) DeleteTables(ctx context.Context, tx *connection.Tx, projectID, datasetID string, tableIDs []string) error {
 	tx.SetProjectAndDataset(projectID, datasetID)
 	if err := tx.ContentRepoMode(); err != nil {
diff --git a/internal/contentdata/repository_test.go b/internal/contentdata/repository_test.go
new file mode 100644
index 000000000..a6514eb77
--- /dev/null
+++ b/internal/contentdata/repository_test.go
@@ -0,0 +1,28 @@
+package contentdata
+
+import "testing"
+
+func TestBigNumericFromBytes(t *testing.T) {
+	tests := []struct {
+		input    []uint8
+		expected string
+	}{
+		{[]uint8{0, 0, 0, 0, 0, 54, 106, 188, 74, 131, 144, 97, 94, 142, 92, 32, 218, 254}, "-1000"},
+		{[]uint8{0, 0, 0, 0, 0, 202, 149, 67, 181, 124, 111, 158, 161, 113, 163, 223, 37, 1}, "1000"},
+		{[]uint8{0, 0, 0, 192, 5, 115, 196, 212, 216, 175, 10, 207, 166, 15, 226, 107, 175, 83, 170, 215, 0}, "12312314324.23423423"},
+		{[]uint8{0, 0, 0, 0, 124, 113, 12, 44, 225, 164, 189, 0, 214, 22, 87, 236, 0}, "3.1415"},
+		{[]uint8{0, 0, 0, 0, 224, 88, 126, 10, 83, 11, 97, 48, 185, 58, 193, 82}, "1.1"},
+		{[]uint8{0, 0, 0, 0, 64, 34, 138, 9, 122, 196, 134, 90, 168, 76, 59, 75}, "1"},
+		{[]uint8{0x00}, "0"},
+	}
+
+	for _, test := range tests {
+		result, err := BigNumericFromBytes(test.input)
+		if err != nil {
+			t.Errorf("BigNumericFromBytes(%v) returned error: %v", test.input, err)
+		}
+		if result != test.expected {
+			t.Errorf("BigNumericFromBytes(%v) = %v; want %v", test.input, result, test.expected)
+		}
+	}
+}