EDIT

import eu.etaxonomy.cdm.database.update.MnTableCreator;

import eu.etaxonomy.cdm.database.update.TableCreator;

        //#6588

        stepName = "Add ExternalLink table";

        tableName = "ExternalLink";

        String[] columnNames = new String[]{"linkType","uri","size"};

        String[] referencedTables = new String[]{null, null, null};

        String[] columnTypes = new String[]{"string_10","clob","int"};

        step = TableCreator.NewVersionableInstance(stepName, tableName,

                columnNames, columnTypes, referencedTables, INCLUDE_AUDIT);

        stepList.add(step);

        //add i18n description

        stepName= "Add i18n description to ExternalLink";

        String firstTableName = "ExternalLink";

        String attributeName = "description";

        step = MnTableCreator.NewDescriptionInstance(stepName, firstTableName, null, attributeName, INCLUDE_AUDIT);

        stepList.add(step);