RedBean ORM performance [closed]

问题

I would like to know, can Redbean ORM be used for performance oriented scenarios like social networking web apps, and is it stable even if thousands of data is pulled by multiple users at same time? Also I'd like to know whether Redbean consumes more memory space?

Can anyone offer a comparison study of Doctrine-Propel-Redbean?

回答1:

@tereško if tis possible, can you give the pros and cons of orm with respect to pure sql according to your experience and also i will google the topic at same time. – Jaison Justus

Well .. explaining this in 600 characters would be hard.

One thing I must clarify: this is about ORMs in PHP, though i am pretty sure it applies to some Ruby ORMs too and maybe others.

In brief, you should avoid them, but if you have to use an ORM, then you will be better of with Doctrine 2.x , it's the lesser evil. (Implements something similar to DataMapper instead of ActiveRecord).

Case against ORMs

The main reason why some developers like to use ORMs is also the worst thing about them: it is easy to do simple thing in ORM, with very minor performance costs. This is perfectly fine.

1. Exponential complexity

The problem originates in people to same tool for everything. If all you have is a hammer (..) type of issue. This results in creating a technical debt.

At first it is easy to write new DB related code. And maybe, because you have a large project, management in first weeks (because later it would case additional issues - read The Mythical Man-Month, if interested in details) decides to hire more people. And you end up preferring people with ORM skills over general SQL.

But, as project progresses, you will begin to use ORM for solving increasingly complex problems. You will start to hack around some limitations and eventually you may end up with problems which just cannot be solved even with all the ORM hacks you know ... and now you do not have the SQL experts, because you did not hire them.

Additionally most of popular ORMs are implementing ActiveRecord, which means that your application's business logic is directly coupled to ORM. And adding new features will take more and more time because of that coupling. And for the same reason, it is extremely hard to write good unit-tests for them.

2. Performance

I already mentioned that even simple uses of ORM (working with single table, no JOIN) have some performance costs. It is due to the fact that they use wildcard * for selecting data. When you need just the list of article IDs and titles, there is no point on fetching the content.

ORMs are really bad at working with multiple tables, when you need data based on multiple conditions. Consider the problem:

Database contains 4 tables: Projects, Presentations, Slides and Bulletpoints.

Projects have many Presentations

Presentations have many Slides

Slides have many Bulletpoitns

And you need to find content from all the Bulletpoints in the Slides tagged as "important" from 4 latest Presentations related to the Projects with ids 2, 4 and 8.

This is a simple JOIN to write in pure SQL, but in any ORM implementation, that i have seen, this will result in 3-level nested loop, with queries at every level.

P.S. there are other reasons and side-effects, but they are relatively minor .. cannot remember any other important issues right now.

回答2:

I feel Tereško's answer is not quite right.

Firstly it does not address the original question. It's indeed a case against ORMs, and I agree with the problems described in his answer. That's why I wrote RedBeanPHP. Just because most ORMs fail to make your life a bit easier does not mean the concept of an object relational mapping system is flawed. Most ORMs try to hide SQL, which is why JOINs get so complex; they need to re-invent something similar in an object oriented environment. This is where RedBeanPHP differs, as it does not hide SQL. It creates readable, valid SQL tables that are easy to query. Instead of a fabricated query language RedBeanPHP uses plain old SQL for record and bean retrieval. In short; RedBeanPHP works with SQL rather than against it. This makes it a lot less complex.

And yes, the performance of RedBeanPHP is good. How can I be so sure? Because unlike other ORMs, RedBeanPHP distinguishes between development mode and production mode. During the development cycle the database is fluid; you can add entries and they will be added dynamically. RedBeanPHP creates the columns, indexes, guesses the data types etc. It even stretches up columns if you need more bytes (higher data type) after a while. This makes RedBeanPHP extremely slow, but only during development time when speed should not be an issue. Once you are done developing you use freeze the database with a single mode specifier R::freeze() and no more checks are done. What you are left with is a pretty straight forward database layer on your production server. And because not much is done, performance is good.

Yes, I know, I am the author of RedBeanPHP so I am biased. However I felt like my ORM was being viewed in the same light as the other ORMs, which prompted me to write this. If you want to know more, feel free to consult the RedBeanPHP website, and here is a discussion on performance.

At our company we use RedBeanPHP for embedded systems as well as financial business systems, so it seems to scale rather well.

Together, me and the RedBeanPHP community are sincerely trying to make the ORM world a better place; you can read the mission statement here.

Good luck with your project and I hope you find the technical solution you are looking for.

回答3:

I differ from @tereško here - ORMs can make database queries easier to write and easier to maintain. There is some great work going into Propel and Doctrine, in my opinion - take advantage of them! There are a number of performance comparisons on the web, and check out NotORM as well (I've not used it but they do some comparisons to Doctrine, if I recall correctly).

If you get to a point where your throughput requires you to do raw SQL then optimise at that point. But in terms of reducing your bug count and increasing your productivity, I think that your savings will fund a better server anyway. Of course, your mileage may vary.

I don't know RedBean, incidentally, but I am mildly of the view that Propel is faster than Doctrine in most cases, since the classes are pre-generated. I used Propel when it was the only option and have stuck with it, though I certainly wouldn't be averse to using Doctrine.

2018 update

Propel 2 is still in alpha after a number of years, and is in need of a number of large refactoring projects, which sadly were not getting done. Although the maintainers say that this alpha is good to use in production, since it has good test coverage, they have now started on Propel 3. Unfortunately, this has not actually had any releases yet, at the time of my writing this, despite the repository being a year old.

While I think Propel was a great project, I wonder if it is best to use something else for the time being. It could yet rise from the ashes!

回答4:

I would go with "Horses for Courses" situation that utilizes a mix and match of both the worlds. I have built few large scale applications using RedBean, so my comment will focus purely on RedBean and not on other ORMs.

IS RedBean ORM SLOW?

Well, it depends on how you use it. In certain scenarios, it's faster than traditional query because RedBean cache the result for few seconds. Reusing the query will produce result faster. Have a look at the log using R::debug(true); It always shows

"SELECT * FROM `table` -- keep-cache"

Scenario 1: Fetching All (*)

In RedBean if you query

$result = R::findOne('table', ' id = ?', array($id));

This is represented as

$result= mysql_query("Select * from TABLE where id =".$id);

You may argue that if the table is having multiple columns why should you query (*).

Scenario 2: Single column

Fetching a single column

R::getCol( 'SELECT first_name FROM accounts' );

Like i mentioned "Horses for Courses", developers should not simply rely on FindOne, FindAll, FindFirst, FindLast but also carefully draft what they really need.

Scenario 3: Caching

When you don't need caching, you can disable at application level which isn't an ideal situation

R::$writer->setUseCache(true);

RedBean suggests that if you don't want to disable caching at the application level you should use traditional query with no-cache parameter like $result = R::exec("SELECT SQL_NO_CACHE * FROM TABLE");

This perfectly solves the problem of fetching real-time data from table by completely discarding query cache.

Scenario 4: Rapid Development

Using ORM makes your application development really fast, developers can code using ORM 2-3x faster than writing SQL.

Scenario 5: Complex Queries & Relationships

RedBean presents a really nice way of implementing complex queries and one-to-many or many-to-many relationships

Plain SQL for complex queries

$books = R::getAll( 'SELECT 
    book.title AS title, 
    author.name AS author, 
    GROUP_CONCAT(category.name) AS categories FROM book
    JOIN author ON author.id = book.author_id
    LEFT JOIN book_category ON book_category.book_id = book.id
    LEFT JOIN category ON book_category.category_id = category.id 
    GROUP BY book.id
    ' );
    foreach( $books as $book ) {
        echo $book['title'];
        echo $book['author'];
        echo $book['categories'];
    }

OR RedBean way of handling many-t-to-many relationships

list($vase, $lamp) = R::dispense('product', 2);

$tag = R::dispense( 'tag' );
$tag->name = 'Art Deco';

//creates product_tag table!
$vase->sharedTagList[] = $tag;
$lamp->sharedTagList[] = $tag;
R::storeAll( [$vase, $lamp] );

Performance Issues

The arguments like ORMs are typically slow, consumes more memory and tends to make an application slow. I think they are not talking about RedBean.

We have tested it with MySQL and Postgres both, trust me performance was never a bottleneck.

There is no denying that ORMs adds up little overhead and tend to make your application slower ( just a little ). Using ORM is primarily a trade-off between developer time and slightly slower runtime performance. My strategy is to first build the application end-to-end with the ORM then based on test cases, tweak the speed critical modules to use straight data access.

来源：https://stackoverflow.com/questions/7765070/redbean-orm-performance

标签

php

orm

doctrine

propel

redbean