notebooks/util/jdbc/engines/mysql_input_manager.py [69:107]:
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        if custom_partition_column:
            # The user provided a partition column.
            column = self._normalise_column_name(
                table, custom_partition_column, sa_connection
            )
            if not column:
                return {
                    PARTITION_COMMENT: f"Serial read, column does not exist: {custom_partition_column}"
                }
            partition_options = self._define_native_column_read_partitioning(
                table,
                column,
                accepted_data_types,
                row_count,
                row_count_threshold,
                "user provided column",
                sa_connection,
            )
            if partition_options:
                return partition_options

        pk_cols = self.get_primary_keys().get(table)
        if pk_cols and len(pk_cols) == 1:
            # Partition by primary key singleton.
            column = pk_cols[0]
            partition_options = self._define_native_column_read_partitioning(
                table,
                column,
                accepted_data_types,
                row_count,
                row_count_threshold,
                "primary key column",
                sa_connection,
            )
            if partition_options:
                return partition_options
        return None

    def _enclose_identifier(self, identifier, ch: Optional[str] = None):
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notebooks/util/jdbc/engines/oracle_input_manager.py [76:116]:
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        if custom_partition_column:
            # The user provided a partition column.
            column = self._normalise_column_name(
                table, custom_partition_column, sa_connection
            )
            if not column:
                return {
                    PARTITION_COMMENT: f"Serial read, column does not exist: {custom_partition_column}"
                }
            partition_options = self._define_native_column_read_partitioning(
                table,
                column,
                accepted_data_types,
                row_count,
                row_count_threshold,
                "user provided column",
                sa_connection,
            )
            if partition_options:
                return partition_options

        # TODO Prioritise partition keys over primary keys in the future.
        # TODO Add support for unique keys alongside PKs.
        pk_cols = self.get_primary_keys().get(table)
        if pk_cols and len(pk_cols) == 1:
            # Partition by primary key singleton.
            column = pk_cols[0]
            partition_options = self._define_native_column_read_partitioning(
                table,
                column,
                accepted_data_types,
                row_count,
                row_count_threshold,
                "primary key column",
                sa_connection,
            )
            if partition_options:
                return partition_options
        return None

    def _enclose_identifier(self, identifier, ch: Optional[str] = None):
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