Should is_paranoid be built into Rails? - ruby-on-rails

Or, put differently, is there any reason not to use it on all of my models?
Some background: is_paranoid is a gem that makes calls to destroy set a deleted_at timestamp rather than deleting the row (and calls to find exclude rows with non-null deleted_ats).
I've found this feature so useful that I'm starting to include it in every model -- hard deleting records is just too scary. Is there any reason this is a bad thing? Should this feature be turned on by default in Rails?


Ruby is not for cowards who are scared of their own code!
In most cases you really want to delete the record completely. Consider a table that contains relationships between two other models. This is an obvious case when you would not like to use deleted_at.
Another thing is that your approach to database design is kinda rubyish. You will suffer of necessity to handle all this deleted_At stuff, when you have to write more complex queries to your tables than mere finds. And you surely will, when your application's DB takes lots of space so you'll have to replace nice and shiny ruby code with hacky SQL queries. You may want then to discard this column, but--oops--you have already utilized deleted_at logic somewhere and you'll have to rewrite larger pieces of your app. Gotcha.
And at the last place, actually it seems natural when things disappear upon deletion. And the whole point of the modelling is that the models try to express in machine-readable terms what's going on there. By default you delete record and it passes forever. And only reason deleted_at may be natural is when a record is to be later restored or should prevent similar record to be confused with the original one (table for Users is most likely the place you want to use it). But in most models it's just paranoia.
What I'm trying to say is that the plausibility to restore deleted records should be an explicitly expressed intent, because it's not what people normally expect and because there are cases where implicit use of it is error prone and not just adds a small overhead (unlike maintaining a created_at column).
Of course, there is a number of cases where you would like to revert deletion of records (especially when accidental deletion of valuable data leads to an unnecessary expenditure). But to utilize it you'll have to modify your application, add forms an so on, so it won't be a problem to add just another line to your model class. And there certainly are other ways you may implement storing deleted data.
So IMHO that's an unnecessary feature for every model and should be only turned on when needed and when this way to add safety to models is applicable to a particular model. And that means not by default.
(This past was influenced by railsninja's valuable remarks).


#Pavel Shved
I'm sorry but what? Ruby is not for cowards scared of code? This could be one of the most ridiculous things I have ever heard. Sure in a join table you want to delete records, but what about the join model of a has many through, maybe not.
In Business applications it often makes good sense to not hard delete things, Users make mistakes, A LOT.
A lot of your response, Pavel, is kind of dribble. There is no shame in using SQL where you need to, and how does using deleted_at cause this massive refactor, I'm at a loss about that.
#Horace I don't think is_paranoid should be in core, not everyone needs it. It's a fantastic gem though, I use it in my work apps and it works great. I am also fairly certain it hasn't forced me to resort to sql when I wouldn't need to, and I can't see a big refactor in my future due to it's presence. Use it when you need it, but it should be a gem.

Related

Are there advantages to using foreign key constraints when working in an active record framework like ruby-on-rails?

I'm moving back into full time web development after a 5 year hiatus. My previous experience (no active record or MVC) tells me to be very thorough with my database schema. Foreign key constraints, unique indexes, etc... can really help out when your writing spaghetti code.
Does the community still find these useful when working in an Active Record / MVC framework?
EDIT
My main concern is managing the constraints in two places; the model code and the db. This means duplicate work and it could lead to bugs. I.e. you have a unique constraint on some field in the database but the model does not know about it? I guess the reverse is true as well, you could just forget to put the constraint in the model then you would have duplicate data when you don't want it.

If you don't use constraints, your database will accumulate cases of broken referential integrity and duplicates where there should be unique values, etc.
More to the point, if you do use constraints (and don't get in the habit of disabling them from time to time as some people do), you'll always have assurance that all your data conforms to your intended data model.
That's the value of database-enforced constraints: it's the only way you can be sure of your data, and you won't have to double-check that your framework (e.g. ActiveRecord) has worked correctly. You won't have to write SQL cleanup scripts to find spurious orphans and duplicates.

It will work fine, however in cases you have to be careful of double click race condition bugs (as validates_uniqueness_of suffers from race conditions).
As far as the model is concerned it doesnt care, the logic in the database is separate to the logic in the Rails app.

Validate FK now or recover from later?

What's the more accepted Rails approach?
Validate that a foreign key exists on creation/update
or
"Damage control" when we want to use the non-existent foreign key?
Initial validation requires more resources on row creation/updating, and may even be redundant when I'm creating rows systematically in my code (i.e. not user generated). However, I can smoothly write my business logic, without fear of running into bad foreign key.
And on the other hand, damage control allows for quick creation and updating, but of course, more checks and recovery in my logic.
Can you think of any other pros and cons? Perhaps there's even more alternatives than just these two doctrines.
How do experienced Rails developers handle this problem?

If by validate ahead of time you mean doing an additional database request just to validate the existence of a key, I would say don't do it. We use FKs all over, and have almost never run into problems, especially not on a create or update. If it does fail, that's probably a good thing, unlike a validation you can do something about, if you just tried to add an association to a no longer existing object, that seems like a pretty good reason for an error to me.
If you have particularly volatile entities such that an instance might frequently have been deleted between the time it is instantiated and the time you try to save it in a FK, then maybe in that particular case it might be worth it, but as a general guide I would not.
I also often use FKs between tables that are deleted using logical deletes (a la acts_as_paranoid, set a deleted_at flag rather than actually delete the row), which also eases the problems of FKs failing, and I find to be a very helpful strategy at least in my app.

The Ruby community values simplicity...what's your argument for simplifying a db schema in a new project?

I'm working on a project with developers who have not worked with Ruby OR Rails before.
They have created a schema that is too complicated, in my opinion. The schema has 117 tables, and obtaining the simplest piece of information would require traversing/joining 7 tabels...and of course, there's no "main" table that serves as a sort of key between them. The schema renders many of the rails tools like 'find' method, and many of the has_many/belongs to relationships almost useless. And coding for all of these relationships will likely be more time-consuming than we have the money to code for.
THE QUESTION:
Assuming you are VERY convinced (IMHO...hehe) that the schema is not ideal, and there are multiple ways to represent the domain, how would you argue FOR simplifying the schema (aside from what I've already said)?

I'll stand up in 2 roles here
DBA: Database admin/designer.
Dev: Application developer.
I assume the DBA is a person who really know all the Database tricks. Reaallyy Knows.
DBA:
Database is the key of the application and should have predefined structure in order to serve its purpose well and with best performance.
If you cannot use random schema (which is reasonably normalised and good) then the tools are wrong.
Dev:
The database is just a data store, so we need to keep it simple and concentrate on the application.
DBA:
Database is not a store it is the core of the application. There is no application without database.
Dev:
No. The application is the core. There is no application without the front-end and the business logic applied to it.
And the war begins...
Both points are valid and it is always trade off.
If the database will ONLY be used by RoR, then you can use it more like a simple store.
If the DB can be used by other application OR it will be used with large amount of data and high traffic it must enforce some best practices.
Generally there is no way you can disagree with DBA.
But they can understand your situation and might allow you to loose the standards a bit so you could be more productive.
So you need to work closely, together.
And you need to talk to each other to explain and prove the point why database should be like this or that.
Otherwise, the team is broken and project can be failure with hight probability.
ActiveRecord is a very handy tool. But it cannot do everything for you. It does not provide Database structure by default that you expect exactly. So it should be tuned.
On the other side. If DBA can accept that all PKs are Auto incremented integers that would make Developer's life easier (ActiveRecord does it by default).
On the other side, if developers would accept some of DBA constraints it would make DBA's life easier.
Now to answer your question:
how would you argue FOR simplifying the schema
Do not argue. Meet the team and deliver the message and point on WHY it should be done.
Maybe it really shouldn't and you don't know all the things, maybe they are not aware of something.
You could agree on the general structure of the database AND try to describe it using RoR migrations as a meta language.
This way they would see the general picture, and you would use your great ActiveRecords.
And also everybody would be on the same page.

Your DB schema should reflect the domain and its relationships.
De-normalisation should only be done when you have measured that there is a performance problem.
7 joins is not excessive or bad, provided you have good indexes in place.

The general way to make this argument up the chain is based on cost. If you do things simply, there will be less code and fewer bugs. The system will be able to be built more quickly, or with more features, and thus will create more ROI. If you can get the money manager on board with that approach, he or she may let you dictate terms to the team. There is the counterargument that extreme over-normalization prevents bad data, but I have found that this is not the case, as the complexity it engenders tends to lead to more errors and more database code in general.
The architectural and technical argument here is simple. You have decided to use Ruby on Rails. Therefore you have decided to use the ActiveRecord pattern. The ActiveRecord pattern is driven by having the database tables match the object model. That's the pattern in use here, and in many other places, so the best practices they are trying to apply for extreme data normalization simply do not apply. Buy a copy of Patterns of Enterprise Application Architecture and put the little red bookmark at page 160 so they can understand how the pattern works from the architecture perspective.
What the DBA types tend to be unaware of is how much work ActiveRecord does for you, from query generation, cascading deletes, optimistic locking, auto populated columns, versioning (with acts_as_versioned), soft deletes (with acts_as_paranoid), etc. There is a strong argument to use well tested, community supported library functions to perform these operations versus custom code that must be maintained by a DBA.
The real issue with DBAs is then that they need some work to do. Let them focus on monitoring performance, finding slow queries in the code, creating indexes and doing backups.
If you end up losing the political battle for a sane schema, you may want to consider switching to DataMapper. It's the next pattern in PoEAA. The other thing you may be able to get them to do is to create views in the database that correspond to the object model. This way, you could use many of the finding capabilities in the ActiveRecord model based on the views, but have custom insert, update, and delete methods.

Is it ever a good idea to use association lists instead of records?

Would any experienced Erlang programmers out there ever recommend association lists over records?
One case might be where two (or more) nodes on different machines are exchanging messages. We want to be able to upgrade the software on each machine independently. Some upgrades may involve adding a field to one (or more) of the messages being sent. It seems like using a record as the message would mean you'd always have to do the upgrade on both machines in lock step so that the extra field didn't cause the receiver to ignore the record. Whereas if you used something like an association list (which still has a "record-like" API), the not-yet-upgraded receiver would still receive the message successfully and just ignore the new field. I realize this isn't always the desired behavior, but often it is. Also, assume the messages are fairly small so the lookup time doesn't matter.
Assuming the above makes some sense, I have the following additional questions:
Is there a standard (or widely used) library for alists? Some trivial googling didn't turn up anything.
Are there other cases where you would use an association list (or something like it)?

You have basically three choices:
Use Records
Use Association Lists (proplists)
Use Combination
I use records where the likelihood of changing it is very low. That way I get the pattern matching and speed up that I want.
I use proplists where I need hashtable like functionality. I get flexibility at the expense of pattern matching and speed.
And sometimes I use both. A record with one field that is a proplist. That way I can pattern match on a portion of it and yet have flexibility where I need it.
All three choices have different trade-offs so you basically just have to evaluate your particular needs and make a choice. It may take some prototyping and playing around to figure out which trade-offs make sense and which features you absolutely must have.

For small amount of keys you can use lists aka proplists for bigger you should use dict. In both cases biggest disadvantage is that you can't use pattern match in way as used for records. There is also speed penalty but it is in most cases irrelevant.

Note that lists:keysearch/3 is pretty much "assq".

Why all the Active Record hate? [closed]

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Closed 11 years ago.
As I learn more and more about OOP, and start to implement various design patterns, I keep coming back to cases where people are hating on Active Record.
Often, people say that it doesn't scale well (citing Twitter as their prime example) -- but nobody actually explains why it doesn't scale well; and / or how to achieve the pros of AR without the cons (via a similar but different pattern?)
Hopefully this won't turn into a holy war about design patterns -- all I want to know is ****specifically**** what's wrong with Active Record.
If it doesn't scale well, why not?
What other problems does it have?

There's ActiveRecord the Design Pattern and ActiveRecord the Rails ORM Library, and there's also a ton of knock-offs for .NET, and other languages.
These are all different things. They mostly follow that design pattern, but extend and modify it in many different ways, so before anyone says "ActiveRecord Sucks" it needs to be qualified by saying "which ActiveRecord, there's heaps?"
I'm only familiar with Rails' ActiveRecord, I'll try address all the complaints which have been raised in context of using it.
#BlaM
The problem that I see with Active Records is, that it's always just about one table
Code:
class Person
belongs_to :company
end
people = Person.find(:all, :include => :company )
This generates SQL with LEFT JOIN companies on companies.id = person.company_id, and automatically generates associated Company objects so you can do people.first.company and it doesn't need to hit the database because the data is already present.
#pix0r
The inherent problem with Active Record is that database queries are automatically generated and executed to populate objects and modify database records
Code:
person = Person.find_by_sql("giant complicated sql query")
This is discouraged as it's ugly, but for the cases where you just plain and simply need to write raw SQL, it's easily done.
#Tim Sullivan
...and you select several instances of the model, you're basically doing a "select * from ..."
Code:
people = Person.find(:all, :select=>'name, id')
This will only select the name and ID columns from the database, all the other 'attributes' in the mapped objects will just be nil, unless you manually reload that object, and so on.

I have always found that ActiveRecord is good for quick CRUD-based applications where the Model is relatively flat (as in, not a lot of class hierarchies). However, for applications with complex OO hierarchies, a DataMapper is probably a better solution. While ActiveRecord assumes a 1:1 ratio between your tables and your data objects, that kind of relationship gets unwieldy with more complex domains. In his book on patterns, Martin Fowler points out that ActiveRecord tends to break down under conditions where your Model is fairly complex, and suggests a DataMapper as the alternative.
I have found this to be true in practice. In cases, where you have a lot inheritance in your domain, it is harder to map inheritance to your RDBMS than it is to map associations or composition.
The way I do it is to have "domain" objects that are accessed by your controllers via these DataMapper (or "service layer") classes. These do not directly mirror the database, but act as your OO representation for some real-world object. Say you have a User class in your domain, and need to have references to, or collections of other objects, already loaded when you retrieve that User object. The data may be coming from many different tables, and an ActiveRecord pattern can make it really hard.
Instead of loading the User object directly and accessing data using an ActiveRecord style API, your controller code retrieves a User object by calling the API of the UserMapper.getUser() method, for instance. It is that mapper that is responsible for loading any associated objects from their respective tables and returning the completed User "domain" object to the caller.
Essentially, you are just adding another layer of abstraction to make the code more managable. Whether your DataMapper classes contain raw custom SQL, or calls to a data abstraction layer API, or even access an ActiveRecord pattern themselves, doesn't really matter to the controller code that is receiving a nice, populated User object.
Anyway, that's how I do it.

I think there is a likely a very different set of reasons between why people are "hating" on ActiveRecord and what is "wrong" with it.
On the hating issue, there is a lot of venom towards anything Rails related. As far as what is wrong with it, it is likely that it is like all technology and there are situations where it is a good choice and situations where there are better choices. The situation where you don't get to take advantage of most of the features of Rails ActiveRecord, in my experience, is where the database is badly structured. If you are accessing data without primary keys, with things that violate first normal form, where there are lots of stored procedures required to access the data, you are better off using something that is more of just a SQL wrapper. If your database is relatively well structured, ActiveRecord lets you take advantage of that.
To add to the theme of replying to commenters who say things are hard in ActiveRecord with a code snippet rejoinder
#Sam McAfee Say you have a User class in your domain, and need to have references to, or collections of other objects, already loaded when you retrieve that User object. The data may be coming from many different tables, and an ActiveRecord pattern can make it really hard.
user = User.find(id, :include => ["posts", "comments"])
first_post = user.posts.first
first_comment = user.comments.first
By using the include option, ActiveRecord lets you override the default lazy-loading behavior.

My long and late answer, not even complete, but a good explanation WHY I hate this pattern, opinions and even some emotions:
1) short version: Active Record creates a "thin layer" of "strong binding" between the database and the application code. Which solves no logical, no whatever-problems, no problems at all. IMHO it does not provide ANY VALUE, except some syntactic sugar for the programmer (which may then use an "object syntax" to access some data, that exists in a relational database). The effort to create some comfort for the programmers should (IMHO...) better be invested in low level database access tools, e.g. some variations of simple, easy, plain hash_map get_record( string id_value, string table_name, string id_column_name="id" ) and similar methods (of course, the concepts and elegance greatly varies with the language used).
2) long version: In any database-driven projects where I had the "conceptual control" of things, I avoided AR, and it was good. I usually build a layered architecture (you sooner or later do divide your software in layers, at least in medium- to large-sized projects):
A1) the database itself, tables, relations, even some logic if the DBMS allows it (MySQL is also grown-up now)
A2) very often, there is more than a data store: file system (blobs in database are not always a good decision...), legacy systems (imagine yourself "how" they will be accessed, many varieties possible.. but thats not the point...)
B) database access layer (at this level, tool methods, helpers to easily access the data in the database are very welcome, but AR does not provide any value here, except some syntactic sugar)
C) application objects layer: "application objects" sometimes are simple rows of a table in the database, but most times they are compound objects anyway, and have some higher logic attached, so investing time in AR objects at this level is just plainly useless, a waste of precious coders time, because the "real value", the "higher logic" of those objects needs to be implemented on top of the AR objects, anyway - with and without AR! And, for example, why would you want to have an abstraction of "Log entry objects"? App logic code writes them, but should that have the ability to update or delete them? sounds silly, and App::Log("I am a log message") is some magnitudes easier to use than le=new LogEntry(); le.time=now(); le.text="I am a log message"; le.Insert();. And for example: using a "Log entry object" in the log view in your application will work for 100, 1000 or even 10000 log lines, but sooner or later you will have to optimize - and I bet in most cases, you will just use that small beautiful SQL SELECT statement in your app logic (which totally breaks the AR idea..), instead of wrapping that small statement in rigid fixed AR idea frames with lots of code wrapping and hiding it. The time you wasted with writing and/or building AR code could have been invested in a much more clever interface for reading lists of log-entries (many, many ways, the sky is the limit). Coders should dare to invent new abstractions to realize their application logic that fit the intended application, and not stupidly re-implement silly patterns, that sound good on first sight!
D) the application logic - implements the logic of interacting objects and creating, deleting and listing(!) of application logic objects (NO, those tasks should rarely be anchored in the application logic objects itself: does the sheet of paper on your desk tell you the names and locations of all other sheets in your office? forget "static" methods for listing objects, thats silly, a bad compromise created to make the human way of thinking fit into [some-not-all-AR-framework-like-]AR thinking)
E) the user interface - well, what I will write in the following lines is very, very, very subjective, but in my experience, projects that built on AR often neglected the UI part of an application - time was wasted on creation obscure abstractions. In the end such applications wasted a lot of coders time and feel like applications from coders for coders, tech-inclined inside and outside. The coders feel good (hard work finally done, everything finished and correct, according to the concept on paper...), and the customers "just have to learn that it needs to be like that", because thats "professional".. ok, sorry, I digress ;-)
Well, admittedly, this all is subjective, but its my experience (Ruby on Rails excluded, it may be different, and I have zero practical experience with that approach).
In paid projects, I often heard the demand to start with creating some "active record" objects as a building block for the higher level application logic. In my experience, this conspicuously often was some kind of excuse for that the customer (a software dev company in most cases) did not have a good concept, a big view, an overview of what the product should finally be. Those customers think in rigid frames ("in the project ten years ago it worked well.."), they may flesh out entities, they may define entities relations, they may break down data relations and define basic application logic, but then they stop and hand it over to you, and think thats all you need... they often lack a complete concept of application logic, user interface, usability and so on and so on... they lack the big view and they lack love for the details, and they want you to follow that AR way of things, because.. well, why, it worked in that project years ago, it keeps people busy and silent? I don't know. But the "details" separate the men from the boys, or .. how was the original advertisement slogan ? ;-)
After many years (ten years of active development experience), whenever a customer mentions an "active record pattern", my alarm bell rings. I learned to try to get them back to that essential conceptional phase, let them think twice, try them to show their conceptional weaknesses or just avoid them at all if they are undiscerning (in the end, you know, a customer that does not yet know what it wants, maybe even thinks it knows but doesn't, or tries to externalize concept work to ME for free, costs me many precious hours, days, weeks and months of my time, live is too short ... ).
So, finally: THIS ALL is why I hate that silly "active record pattern", and I do and will avoid it whenever possible.
EDIT: I would even call this a No-Pattern. It does not solve any problem (patterns are not meant to create syntactic sugar). It creates many problems: the root of all its problems (mentioned in many answers here..) is, that it just hides the good old well-developed and powerful SQL behind an interface that is by the patterns definition extremely limited.
This pattern replaces flexibility with syntactic sugar!
Think about it, which problem does AR solve for you?

Some messages are getting me confused.
Some answers are going to "ORM" vs "SQL" or something like that.
The fact is that AR is just a simplification programming pattern where you take advantage of your domain objects to write there database access code.
These objects usually have business attributes (properties of the bean) and some behaviour (methods that usually work on these properties).
The AR just says "add some methods to these domain objects" to database related tasks.
And I have to say, from my opinion and experience, that I do not like the pattern.
At first sight it can sound pretty good. Some modern Java tools like Spring Roo uses this pattern.
For me, the real problem is just with OOP concern. AR pattern forces you in some way to add a dependency from your object to infraestructure objects. These infraestructure objects let the domain object to query the database through the methods suggested by AR.
I have always said that two layers are key to the success of a project. The service layer (where the bussiness logic resides or can be exported through some kind of remoting technology, as Web Services, for example) and the domain layer. In my opinion, if we add some dependencies (not really needed) to the domain layer objects for resolving the AR pattern, our domain objects will be harder to share with other layers or (rare) external applications.
Spring Roo implementation of AR is interesting, because it does not rely on the object itself, but in some AspectJ files. But if later you do not want to work with Roo and have to refactor the project, the AR methods will be implemented directly in your domain objects.
Another point of view. Imagine we do not use a Relational Database to store our objects. Imagine the application stores our domain objects in a NoSQL Database or just in XML files, for example. Would we implement the methods that do these tasks in our domain objects? I do not think so (for example, in the case of XM, we would add XML related dependencies to our domain objects...Truly sad I think). Why then do we have to implement the relational DB methods in the domain objects, as the Ar pattern says?
To sum up, the AR pattern can sound simpler and good for small and simple applications. But, when we have complex and large apps, I think the classical layered architecture is a better approach.

The question is about the Active
Record design pattern. Not an orm
Tool.
The original question is tagged with rails and refers to Twitter which is built in Ruby on Rails. The ActiveRecord framework within Rails is an implementation of Fowler's Active Record design pattern.

The main thing that I've seen with regards to complaints about Active Record is that when you create a model around a table, and you select several instances of the model, you're basically doing a "select * from ...". This is fine for editing a record or displaying a record, but if you want to, say, display a list of the cities for all the contacts in your database, you could do "select City from ..." and only get the cities. Doing this with Active Record would require that you're selecting all the columns, but only using City.
Of course, varying implementations will handle this differently. Nevertheless, it's one issue.
Now, you can get around this by creating a new model for the specific thing you're trying to do, but some people would argue that it's more effort than the benefit.
Me, I dig Active Record. :-)
HTH

Although all the other comments regarding SQL optimization are certainly valid, my main complaint with the active record pattern is that it usually leads to impedance mismatch. I like keeping my domain clean and properly encapsulated, which the active record pattern usually destroys all hope of doing.

I love the way SubSonic does the one column only thing.
Either
DataBaseTable.GetList(DataBaseTable.Columns.ColumnYouWant)
, or:
Query q = DataBaseTable.CreateQuery()
.WHERE(DataBaseTable.Columns.ColumnToFilterOn,value);
q.SelectList = DataBaseTable.Columns.ColumnYouWant;
q.Load();
But Linq is still king when it comes to lazy loading.

#BlaM:
Sometimes I justed implemented an active record for a result of a join. Doesn't always have to be the relation Table <--> Active Record. Why not "Result of a Join statement" <--> Active Record ?

I'm going to talk about Active Record as a design pattern, I haven't seen ROR.
Some developers hate Active Record, because they read smart books about writing clean and neat code, and these books states that active record violates single resposobility principle, violates DDD rule that domain object should be persistant ignorant, and many other rules from these kind of books.
The second thing domain objects in Active Record tend to be 1-to-1 with database, that may be considered a limitation in some kind of systems (n-tier mostly).
Thats just abstract things, i haven't seen ruby on rails actual implementation of this pattern.

The problem that I see with Active Records is, that it's always just about one table. That's okay, as long as you really work with just that one table, but when you work with data in most cases you'll have some kind of join somewhere.
Yes, join usually is worse than no join at all when it comes to performance, but join usually is better than "fake" join by first reading the whole table A and then using the gained information to read and filter table B.

The problem with ActiveRecord is that the queries it automatically generates for you can cause performance problems.
You end up doing some unintuitive tricks to optimize the queries that leave you wondering if it would have been more time effective to write the query by hand in the first place.

Try doing a many to many polymorphic relationship. Not so easy. Especially when you aren't using STI.

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