Delete records using Map Reduce script

Delete a record using Map Reduce
Map Reduce is an asynchronous type script which allow concurrent processing of records.
Given Sample delete a records satisfying a give search conditions

/**
 * @NApiVersion 2.x
 * @NScriptType MapReduceScript
 * @NModuleScope SameAccount
 */
//--------------------------------------------------------
//   delete the maint for all deleted opportunitites
//--------------------------------------------------------
define(['N/search', 'N/record'], function (search, record) {
    
            var OPP = {
            type: "opportunity",
            maint: "custbody_jj_ismaintprocessed"
        };

        var MFR = {
            type: "customrecord_esw_mfr_maint_file_table",
            field: {
                opportunity: "custrecord_esw_mfr_opportunity",
                base: "custrecord_esw_mfr_base_usd",
                listRate: "custrecord_esw_mfr_listrate_usd",
                currency: "custrecord_esw_mfr_currency",
                startDate: "custrecord_esw_mfr_start_date"
            }
        };

    function deleteMaint(scriptContext) {

        try {
            record.delete({
                id: scriptContext.key,
                type: MFR.type
            });
            
        } catch (err) {
            log.debug("error@deleteMaint", err);
        }
    }




    return {
        
        getInputData: function (scriptContext) {
            return search.create({
                type: MFR.type,
                filters: [MFR.field.opportunity, "anyof", "@NONE@"],
                columns: ["internalid"]
            })
        },
        reduce: deleteMaint,
        summarize:function(summary){
            try {
                log.debug('summary@summarize', summary);
            } catch (err) {
                log.debug('err@summarize', err);
            }

        }
    }

});