presto-hive/src/main/java/io/prestosql/plugin/hive/metastore/SemiTransactionalHiveMetastore.java/SemiTransactionalHiveMetastore/addColumn
class SemiTransactionalHiveMetastore:    public synchronized void addColumn(HiveIdentity identity, String databaseName, String tableName, String columnName, HiveType columnType, String columnComment)
    {
        setExclusive((delegate, hdfsEnvironment) -> delegate.addColumn(identity, databaseName, tableName, columnName, columnType, columnComment));
    }