AWSDAX表扫描性能问题
- 使用DAX缓存优化查询性能。确保DAX已正确设置，并在查询中使用DAX查询语句而不是表扫描。以下是一些示例代码：
// 使用DAX查询语句 const AWS = require('aws-sdk'); AWS.config.update({region: 'us-west-2'}); const dax = new AWS.DAX({endpoint: 'your-dax-endpoint.com', region: 'us-west-2'}); const daxClient = new AWS.DynamoDB.DocumentClient({service: dax}); const params = { TableName: 'my-table', KeyConditionExpression: 'PartitionKey = :pk AND begins_with(SortKey, :sk)', ExpressionAttributeValues: { ':pk': 'my-partition-key-value', ':sk': 'my-sort-key-prefix' } }; daxClient.query(params, function(err, data) { if (err) console.log(err); else console.log(data); });
// 使用表扫描 const AWS = require('aws-sdk'); AWS.config.update({region: 'us-west-2'}); const ddbClient = new AWS.DynamoDB.DocumentClient(); const params = { TableName: 'my-table', FilterExpression: '#attr = :value', ExpressionAttributeNames: {'#attr': 'my-attribute'}, ExpressionAttributeValues: {':value': 'my-value'} }; ddbClient.scan(params, function(err, data) { if (err) console.log(err); else console.log(data); });
- 当表太大，无法放入DAX集群时，使用AWS DynamoDB Accelerator (DAX) Client，以最小化DynamoDB的读取压力，提高对远程表的访问性能。示例代码：
const AWS = require('aws-sdk'); const proxy = require('proxy-agent'); AWS.config.update({ httpOptions: { agent: proxy('http://username:password@your-proxy.com') }, region: 'us-west-2' }); const DaxClient = require('amazon-dax-client'); const dax = new DaxClient({ endpoints: ['your-dax-endpoint.com:8111'],