fix: size bigint unsigned as numeric(20,0); commit table migration tx

pkg/redshift/redshift.go

@@ -1392,6 +1392,13 @@ func GetRedshiftDataType(sqlType, debeziumType, sourceColType,
 			}
 		}
 
+		// BIGINT UNSIGNED propagates no column length, and the default
+		// numeric(18,0) cannot hold its full range: COPY fails with
+		// "Overflow for NUMERIC(18,0)". Size it to 20 digits.
+		if sourceColType == "bigint unsigned" && sourceColLength == "" {
+			sourceColLength = "20"
+		}
+
 		return applyLength(
 			RedshiftToMysqlCharacterRatio,
 			redshiftType,

pkg/redshift/redshift_test.go

@@ -337,6 +337,39 @@ func TestRedshiftDataTypeGet(t *testing.T) {
 			expectedResult:  "boolean",
 			expectError:     false,
 		},
+		{
+			name:            "test29: BIGINT UNSIGNED without length covers full range",
+			sqlType:         "mysql",
+			debeziumType:    "string",
+			sourceColType:   "BIGINT UNSIGNED",
+			sourceColLength: "",
+			sourceColScale:  "",
+			columnMasked:    false,
+			expectedResult:  "numeric(20,0)",
+			expectError:     false,
+		},
+		{
+			name:            "test30: BIGINT UNSIGNED with explicit length is respected",
+			sqlType:         "mysql",
+			debeziumType:    "string",
+			sourceColType:   "BIGINT UNSIGNED",
+			sourceColLength: "22",
+			sourceColScale:  "",
+			columnMasked:    false,
+			expectedResult:  "numeric(22,0)",
+			expectError:     false,
+		},
+		{
+			name:            "test31: BIGINT UNSIGNED masked stays varchar",
+			sqlType:         "mysql",
+			debeziumType:    "string",
+			sourceColType:   "BIGINT UNSIGNED",
+			sourceColLength: "",
+			sourceColScale:  "",
+			columnMasked:    true,
+			expectedResult:  "character varying(50)",
+			expectError:     false,
+		},
 	}
 
 	for _, tc := range tests {

pkg/redshiftloader/load_processor.go

@@ -577,7 +577,6 @@ func (b *loadProcessor) migrateTable(
 		if err != nil {
 			return err
 		}
-		return err
 	}
 
 	err = tx.Commit()