I am developing an application with laravel framework, and I want to measure orm query (CRUD) performance and compare it with RDBMS query performance.
I need to show that orm query performance is better than RDBMS but somewhere I read that eloquent laravel has a slow query performance. I need to make the right decision in order to show the desired result. Is doctrine better than eloquent ORM? And also which benchmark do you suggest me to use. I need these results for my thesis.
You're comparing apples to oranges here.
By definition, an RDBMS is always going to be faster, because the RDBMS is your database (RDBMS = Relational Database Management System). IE -- MySQL, SQL Server, PostgreSQL, etc. And the database does one thing really, really well -- handle data (okay, two things, depending on how you look at it -- storing and retrieving data).
Since every way of accessing the database from any other language is at least one step removed from the database itself, everything is slower than the RDBMS itself, if for no other reason than the language's interpreter has to first connect to the database at least once, before it can do anything.
That said, there are a few different layers available when dealing with databases in PHP:
mysql_* functions.Assuming perfectly optimized queries fed into the given method by the developer, raw queries will be fastest, followed by the basic DBAL, followed by anything built on top of the basic DBAL. Where query builders and the ORMs built on them fall will depend on whether the query builder is, itself, built on top of another DBAL (in this case, I think it puts Eloquent one more layer removed than Doctrine, because Eloquent is built on Query Builder, which is built on PDO). This is because each one is an abstraction layer over the previous, so the path of the code, when executed, has to run through the stack.
The question then becomes how much of a difference are we talking? That depends entirely on the queries you're feeding into the system, as well as the quality of the system, itself. What are you looking for to show differences? How fast it can do a basic SELECT? Or how well it can do some crazy multi-JOIN query? What determines "speed" for the purpose of your thesis? Only you can really decide that, because you have more information than anyone here. For the sake of thoroughness, you're probably looking at basic SELECTs, complex queries that include things like JOINs, ORDER BYs, and GROUP BYs, and INSERT and UPDATE commands.
I will tell you this, though -- any test to show speed differences will likely have be on thousands or tens of thousands of transactions, at least, in order to show any significant differences, because on an individual transaction level, we're talking microseconds and possibly even nanoseconds in differences.
In actual industry use, then, how do we decide what route to go? Speed and ease of writing and maintaining the code. In that aspect, ORMs or DBALs will very often beat out raw queries. The fractions of a second per script run lost to the abstraction overhead is recuperated thousands upon thousands of times over in developer costs for time spent writing and maintaining the code in question.
In fact, by the time you get to the point where ORM vs DBAL vs raw queries actually matters, odds are good that you're starting to question whether your original database, language interpreter, or server is up to par with your software's demands. This is actually the issue that Facebook started facing a couple of years ago, at which point they started offloading some of their PHP to C, because C is faster in certain cases. It's also why they've created a completely new interpreter for PHP code (HipHop Virtual Machine, or HHVM), which is quite a bit faster than the original PHP engine.