Sql 为什么Prisma生成唯一索引，而不是基于方案上的唯一列约束

我知道"唯一索引"等同于唯一列约束，但在读取原始SQL时，这不是更清楚了吗？避免与纯粹出于性能原因而创建的索引混淆？

以下是直接取自Prisma的QuickStart文档的示例模式:

// This is your Prisma schema file,
// learn more about it in the docs: https://pris.ly/d/prisma-schema

generator client {
  provider = "prisma-client-js"
}

datasource db {
  provider = "sqlite"
  url      = env("DATABASE_URL")
}

model User {
  id    Int     @id @default(autoincrement()) 
  email String  @unique
  name  String?
  posts Post[]
}

model Post {
  id        Int     @id @default(autoincrement())
  title     String
  content   String?
  published Boolean @default(false) 
  author    User    @relation(fields: [authorId], references: [id])
  authorId  Int
}

请注意"邮箱"唯一声明是如何在模式(SQLite)末尾的唯一索引中实现的:

SELECT sql FROM sqlite_schema;
CREATE TABLE "_prisma_migrations" (
    "id"                    TEXT PRIMARY KEY NOT NULL,
    "checksum"              TEXT NOT NULL,
    "finished_at"           DATETIME,
    "migration_name"        TEXT NOT NULL,
    "logs"                  TEXT,
    "rolled_back_at"        DATETIME,
    "started_at"            DATETIME NOT NULL DEFAULT current_timestamp,
    "applied_steps_count"   INTEGER UNSIGNED NOT NULL DEFAULT 0
)

CREATE TABLE "User" (
    "id" INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
    "email" TEXT NOT NULL,
    "name" TEXT
)
CREATE TABLE sqlite_sequence(name,seq)
CREATE TABLE "Post" (
    "id" INTEGER NOT NULL PRIMARY KEY AUTOINCREMENT,
    "title" TEXT NOT NULL,
    "content" TEXT,
    "published" BOOLEAN NOT NULL DEFAULT false,
    "authorId" INTEGER NOT NULL,
    CONSTRAINT "Post_authorId_fkey" FOREIGN KEY ("authorId") REFERENCES "User" ("id") ON DELETE RESTRICT ON UPDATE CASCADE
)
CREATE UNIQUE INDEX "User_email_key" ON "User"("email")

我试着猜测可能是什么原因.我最好的猜测是，Prisma的内部逻辑更倾向于拥有尽可能多的内容作为索引，但可能还有另一个原因.