AWS code-library documentation change
Summary
Added code examples for comparing multiple values with IN operator vs OR conditions in DynamoDB queries, including performance comparisons and large value handling
Security assessment
The changes demonstrate query optimization techniques and operator usage without addressing security vulnerabilities or security features. Focus is on performance and expression complexity.
Diff
diff --git a/code-library/latest/ug/java_2_dynamodb_code_examples.md b/code-library/latest/ug/java_2_dynamodb_code_examples.md index dbecbb352..7aed400d3 100644 --- a//code-library/latest/ug/java_2_dynamodb_code_examples.md +++ b//code-library/latest/ug/java_2_dynamodb_code_examples.md @@ -2208,0 +2209,387 @@ For complete source code and instructions on how to set up and run, see the full +The following code example shows how to compare multiple values with a single attribute in DynamoDB. + + * Use the IN operator to compare multiple values with a single attribute. + + * Compare the IN operator with multiple OR conditions. + + * Understand the performance and expression complexity benefits of using IN. + + + + +**SDK for Java 2.x** + + +Compare multiple values with a single attribute in DynamoDB using AWS SDK for Java 2.x. + + + import software.amazon.awssdk.services.dynamodb.DynamoDbClient; + import software.amazon.awssdk.services.dynamodb.model.AttributeValue; + import software.amazon.awssdk.services.dynamodb.model.DynamoDbException; + import software.amazon.awssdk.services.dynamodb.model.QueryRequest; + import software.amazon.awssdk.services.dynamodb.model.QueryResponse; + import software.amazon.awssdk.services.dynamodb.model.ScanRequest; + import software.amazon.awssdk.services.dynamodb.model.ScanResponse; + + import java.util.ArrayList; + import java.util.HashMap; + import java.util.List; + import java.util.Locale; + import java.util.Map; + + /** + * Queries a table using the IN operator to compare multiple values with a single attribute. + * + * <p>This method demonstrates how to use the IN operator in a filter expression + * to match an attribute against multiple values. + * + * @param dynamoDbClient The DynamoDB client + * @param tableName The name of the DynamoDB table + * @param partitionKeyName The name of the partition key attribute + * @param partitionKeyValue The value of the partition key to query + * @param attributeName The name of the attribute to compare + * @param valuesList List of values to compare against + * @return The query response from DynamoDB + * @throws DynamoDbException if an error occurs during the operation + */ + public static QueryResponse compareMultipleValues( + DynamoDbClient dynamoDbClient, + String tableName, + String partitionKeyName, + AttributeValue partitionKeyValue, + String attributeName, + List<AttributeValue> valuesList) { + + // Create expression attribute names + Map<String, String> expressionAttributeNames = new HashMap<>(); + expressionAttributeNames.put("#pkName", partitionKeyName); + expressionAttributeNames.put("#attrName", attributeName); + + // Create expression attribute values + Map<String, AttributeValue> expressionAttributeValues = new HashMap<>(); + expressionAttributeValues.put(":pkValue", partitionKeyValue); + + // Add values for IN operator + for (int i = 0; i < valuesList.size(); i++) { + expressionAttributeValues.put(":val" + i, valuesList.get(i)); + } + + // Build the IN clause + StringBuilder inClause = new StringBuilder(); + for (int i = 0; i < valuesList.size(); i++) { + if (i > 0) { + inClause.append(", "); + } + inClause.append(":val").append(i); + } + + // Define the query parameters + QueryRequest request = QueryRequest.builder() + .tableName(tableName) + .keyConditionExpression("#pkName = :pkValue") + .filterExpression("#attrName IN (" + inClause.toString() + ")") + .expressionAttributeNames(expressionAttributeNames) + .expressionAttributeValues(expressionAttributeValues) + .build(); + + // Perform the query operation + return dynamoDbClient.query(request); + } + + /** + * Queries a table using multiple OR conditions to compare multiple values with a single attribute. + * + * <p>This method demonstrates the alternative approach to using the IN operator, + * by using multiple OR conditions. + * + * @param dynamoDbClient The DynamoDB client + * @param tableName The name of the DynamoDB table + * @param partitionKeyName The name of the partition key attribute + * @param partitionKeyValue The value of the partition key to query + * @param attributeName The name of the attribute to compare + * @param valuesList List of values to compare against + * @return The query response from DynamoDB + * @throws DynamoDbException if an error occurs during the operation + */ + public static QueryResponse compareWithOrConditions( + DynamoDbClient dynamoDbClient, + String tableName, + String partitionKeyName, + AttributeValue partitionKeyValue, + String attributeName, + List<AttributeValue> valuesList) { + + // Create expression attribute names + Map<String, String> expressionAttributeNames = new HashMap<>(); + expressionAttributeNames.put("#pkName", partitionKeyName); + expressionAttributeNames.put("#attrName", attributeName); + + // Create expression attribute values + Map<String, AttributeValue> expressionAttributeValues = new HashMap<>(); + expressionAttributeValues.put(":pkValue", partitionKeyValue); + + // Add values for OR conditions + for (int i = 0; i < valuesList.size(); i++) { + expressionAttributeValues.put(":val" + i, valuesList.get(i)); + } + + // Build the OR conditions + StringBuilder orConditions = new StringBuilder(); + for (int i = 0; i < valuesList.size(); i++) { + if (i > 0) { + orConditions.append(" OR "); + } + orConditions.append("#attrName = :val").append(i); + } + + // Define the query parameters + QueryRequest request = QueryRequest.builder() + .tableName(tableName) + .keyConditionExpression("#pkName = :pkValue") + .filterExpression(orConditions.toString()) + .expressionAttributeNames(expressionAttributeNames) + .expressionAttributeValues(expressionAttributeValues) + .build(); + + // Perform the query operation + return dynamoDbClient.query(request); + } + + /** + * Compares the performance of using the IN operator versus multiple OR conditions. + * + * <p>This method demonstrates the performance difference between using the IN operator + * and using multiple OR conditions. + * + * @param dynamoDbClient The DynamoDB client + * @param tableName The name of the DynamoDB table + * @param partitionKeyName The name of the partition key attribute + * @param partitionKeyValue The value of the partition key to query + * @param attributeName The name of the attribute to compare + * @param valuesList List of values to compare against + * @return Map containing the performance comparison results + */ + public static Map<String, Object> comparePerformance( + DynamoDbClient dynamoDbClient, + String tableName, + String partitionKeyName, + AttributeValue partitionKeyValue, + String attributeName, + List<AttributeValue> valuesList) { + + Map<String, Object> results = new HashMap<>(); + + try { + // Measure performance of IN operator + long inStartTime = System.nanoTime(); + QueryResponse inResponse = compareMultipleValues( + dynamoDbClient, tableName, partitionKeyName, partitionKeyValue, attributeName, valuesList); + long inEndTime = System.nanoTime(); + long inDuration = inEndTime - inStartTime; + + // Measure performance of OR conditions + long orStartTime = System.nanoTime(); + QueryResponse orResponse = compareWithOrConditions( + dynamoDbClient, tableName, partitionKeyName, partitionKeyValue, attributeName, valuesList); + long orEndTime = System.nanoTime(); + long orDuration = orEndTime - orStartTime; + + // Record results + results.put("inOperatorDuration", inDuration); + results.put("orConditionsDuration", orDuration); + results.put("inOperatorItems", inResponse.count()); + results.put("orConditionsItems", orResponse.count()); + results.put("inOperatorExpression", "IN operator with " + valuesList.size() + " values"); + results.put("orConditionsExpression", valuesList.size() + " OR conditions");