# 1. 优化数据模型
// 订单文档结构
{
_id: ObjectId,
user_id: ObjectId,
order_id: String,
amount: Number,
status: String,
items: [
{ product_id: ObjectId, quantity: Number, price: Number }
],
created_at: Date,
updated_at: Date
}

# 2. 创建索引
fgedudb> db.fgedu_orders.createIndex({ order_id: 1 }, { unique: true })
fgedudb> db.fgedu_orders.createIndex({ user_id: 1, created_at: -1 })
fgedudb> db.fgedu_orders.createIndex({ status: 1 })

# 3. 使用批量写入
fgedudb> function createOrders(orders) {
return db.fgedu_orders.insertMany(orders, {
ordered: false, // 无序插入，提高性能
writeConcern: { w: 1 } // 只需要主节点确认
});
}

# 4. 测试高并发写入
fgedudb> const orders = [];
for (let i = 0; i < 1000; i++) { orders.push({ user_id: ObjectId("6614f8a0a1b2c3d4e5f6g7h8"), order_id: "order" + i, amount: Math.floor(Math.random() * 1000) + 1, status: "pending", items: [ { product_id: ObjectId("6614f8a0a1b2c3d4e5f6g7h9"), quantity: 1, price: 100 } ], created_at: new Date(), updated_at: new Date() }); } fgedudb> const start = new Date();
fgedudb> createOrders(orders);
fgedudb> const end = new Date();
fgedudb> print(`插入1000条订单耗时: ${end – start}ms`);

# 1. 优化数据模型
// 商品文档结构
{
_id: ObjectId,
name: String,
category: String,
price: Number,
stock: Number,
description: String,
tags: [String],
created_at: Date,
updated_at: Date
}

# 2. 创建索引
fgedudb> db.fgedu_products.createIndex({ name: “text”, description: “text” });
fgedudb> db.fgedu_products.createIndex({ category: 1, price: 1 });
fgedudb> db.fgedu_products.createIndex({ tags: 1 });

# 3. 使用投影减少返回数据
fgedudb> db.fgedu_products.find(
{ category: “electronics”, price: { $gte: 100, $lte: 1000 } },
{ name: 1, price: 1, stock: 1, _id: 0 }
).sort({ price: 1 });

# 4. 使用limit限制结果数量
fgedudb> db.fgedu_products.find(
{ category: “electronics” }
).sort({ price: 1 }).limit(20);

# 5. 测试并发查询
fgedudb> function searchProducts(query) {
return db.fgedu_products.find(query).toArray();
}

fgedudb> const queries = [
{ category: “electronics” },
{ price: { $lt: 500 } },
{ tags: “popular” },
{ $text: { $search: “laptop” } }
];

fgedudb> const start = new Date();
for (let i = 0; i < 100; i++) { const query = queries[i % queries.length]; searchProducts(query); } fgedudb> const end = new Date();
fgedudb> print(`执行100次查询耗时: ${end – start}ms`);

# 1. 优化数据模型
// 用户文档结构
{
_id: ObjectId,
name: String,
balance: Number,
created_at: Date,
updated_at: Date
}

// 交易文档结构
{
_id: ObjectId,
from_user_id: ObjectId,
to_user_id: ObjectId,
amount: Number,
status: String,
created_at: Date,
updated_at: Date
}

# 2. 创建索引
fgedudb> db.fgedu_users.createIndex({ _id: 1 });
fgedudb> db.fgedu_transactions.createIndex({ from_user_id: 1, created_at: -1 });
fgedudb> db.fgedu_transactions.createIndex({ to_user_id: 1, created_at: -1 });

# 3. 实现转账事务
fgedudb> function transfer(fromUserId, toUserId, amount) {
const session = db.getMongo().startSession();

try {
session.startTransaction({
readConcern: { level: “snapshot” },
writeConcern: { w: “majority” }
});

// 检查转出账户余额
const fromUser = db.fgedu_users.findOne({ _id: fromUserId }, { session });
if (!fromUser || fromUser.balance < amount) { throw new Error("Insufficient balance"); } // 检查转入账户是否存在 const toUser = db.fgedu_users.findOne({ _id: toUserId }, { session }); if (!toUser) { throw new Error("Recipient not found"); } // 更新转出账户余额 db.fgedu_users.updateOne( { _id: fromUserId }, { $inc: { balance: -amount }, $set: { updated_at: new Date() } }, { session } ); // 更新转入账户余额 db.fgedu_users.updateOne( { _id: toUserId }, { $inc: { balance: amount }, $set: { updated_at: new Date() } }, { session } ); // 记录交易 db.fgedu_transactions.insertOne( { from_user_id: fromUserId, to_user_id: toUserId, amount: amount, status: "completed", created_at: new Date(), updated_at: new Date() }, { session } ); // 提交事务 session.commitTransaction(); print("Transfer completed successfully"); return true; } catch (error) { // 回滚事务 session.abortTransaction(); print("Transfer failed:", error); return false; } finally { // 结束会话 session.endSession(); } } # 4. 测试事务处理 fgedudb> const fromUserId = ObjectId(“6614f8a0a1b2c3d4e5f6g7h8”);
const toUserId = ObjectId(“6614f8a0a1b2c3d4e5f6g7h9”);
const amount = 100;

fgedudb> transfer(fromUserId, toUserId, amount);