// Large Data Volume Patterns public class LargeDataVolumeService { // 1. Efficient pagination with query locator public static List getAccountsPage(Integer pageSize, Integer offset) { return [ SELECT Id, Name, Industry, CreatedDate FROM Account WHERE Industry != null // Selective filter ORDER BY CreatedDate DESC LIMIT :pageSize OFFSET :offset ]; } // 2. Chunked processing for LDV public static void processLargeDataSet() { // Use Batch Apex for millions of records Database.executeBatch(new LargeAccountBatch(), 200); } // 3. Avoiding data skew in lookups public static void distributeLoad(List cases) { // BAD: All cases assigned to one queue // GOOD: Distribute across multiple queues List queues = [ SELECT Id FROM Group WHERE Type = 'Queue' AND Name LIKE 'Support_%' ]; if (queues.isEmpty()) return; Integer queueIndex = 0; for (Case c : cases) { c.OwnerId = queues[Math.mod(queueIndex, queues.size())].Id; queueIndex++; } } // 4. Using Big Objects for archival // Big Object definition (metadata) // Customer_Interaction__b with fields: // Account_Id__c (Text, Index 1) // Interaction_Date__c (DateTime, Index 2) // Description__c (Text) public static void archiveTooBigObject(List records) { List bigObjRecords = new List(); for (Customer_Interaction__c rec : records) { bigObjRecords.add(new Customer_Interaction__b( Account_Id__c = rec.Account__c, Interaction_Date__c = rec.Interaction_Date__c, Description__c = rec.Description__c )); } // Async insert into Big Object Database.insertImmediate(bigObjRecords); // Delete from standard object delete records; } // 5. Selective query example with custom index public static List selectiveQuery(String industry, Date createdAfter) { // This query is selective because: // - Industry can be indexed (request custom index) // - CreatedDate is auto-indexed // Both conditions filter >90% of records return [ SELECT Id, Name, Industry, AnnualRevenue FROM Account WHERE Industry = :industry // Indexed field AND CreatedDate > :createdAfter // Auto-indexed ORDER BY Name LIMIT 2000 ]; } } // 6. Batch for LDV processing public class LargeAccountBatch implements Database.Batchable { public Database.QueryLocator start(Database.BatchableContext bc) { // QueryLocator can retrieve up to 50 MILLION records return Database.getQueryLocator([ SELECT Id, Name, Industry, Last_Review_Date__c FROM Account WHERE Last_Review_Date__c < LAST_N_DAYS:365 OR Last_Review_Date__c = null ]); } public void execute(Database.BatchableContext bc, List scope) { for (Account acc : scope) { acc.Last_Review_Date__c = Date.today(); acc.Review_Status__c = 'Pending'; } Database.update(scope, false); // Partial success } public void finish(Database.BatchableContext bc) { System.debug('Batch complete'); } }

Phase 6: Data Management & Advanced Security

0 of 2 topics completed

Large Data Volume Management

Shield Platform Encryption & Compliance

🎤 Mock Interview