# Active Record speed

**URL:** <https://www.ruby-forum.com/t/active-record-speed/74516>\
**Category:** Ruby\
**Created:** [November 7, 2006, 10:46am UTC](https://www.ruby-forum.com/t/active-record-speed/74516 "2006-11-07T10:46:34Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![bizzz](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/bbe5ce/32.png) [@bizzz](https://www.ruby-forum.com/u/bizzz)\
**Post date:** [November 7, 2006, 10:46am UTC](https://www.ruby-forum.com/t/active-record-speed/74516/1 "2006-11-07T10:46:34Z")

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Hello,

I’m writing some code that loads data into a database on a  
routine basis (dump from legacy system daily). I’ve got a  
decent amount of data, and am loading it now using ActiveRecord.

I’m finding that it’s taking quite a while longer to process  
than I had hoped. To see if it’s my ruby, or ActiveRecord  
that is the cause I’d like to write an implementation that  
loads the data using the underlying ActiveRecord connection  
rather than ActiveRecord objects.

I come from a Perl DBI and JDBC world, and would like to use  
prepared statements. So I’ve gotten the underlying Mysql  
connection (using ActiveRecord::Base.connection.raw\_connection).

When I have code like

stmt = conn.prepare(%Q/  
INSERT INTO sometable (t1,t2,t3,t4)  
VALUES (?,?,?,?)  
/)

bind\_params = [1,2,3,4]

stmt.execute(bind\_params)

I get an error on the execute statement. It claims I need  
to send it 4 parameters. I’d like to send it an array  
containing the paramaters because I build the prepared  
statement based on the format of my data file. The  
bind\_params is then an array which is the result of a split  
on a line in a data file.

So what’s the best way to handle this? Should I begin to  
use Ruby’s DBI rather than just steeling the underlying  
ActiveRecord connections?

Thanks.

Andy

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<div class="post-metadata">

**Author:** ![bizzz](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/bbe5ce/32.png) [@bizzz](https://www.ruby-forum.com/u/bizzz)\
**Post date:** [November 7, 2006, 10:46am UTC](https://www.ruby-forum.com/t/active-record-speed/74516/2 "2006-11-07T10:46:38Z")

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Andrew L. wrote:

> ActiveRecord connection rather than ActiveRecord objects.  
> /)
> 
> bind\_params = [1,2,3,4]
> 
> stmt.execute(bind\_params)

You probably just need to change the line above to

stmt.execute(\*bind\_params)

> I get an error on the execute statement. It claims I need to send it 4  
> parameters. I’d like to send it an array containing the paramaters  
> because I build the prepared statement based on the format of my data  
> file. The bind\_params is then an array which is the result of a split  
> on a line in a data file.
> 
> So what’s the best way to handle this? Should I begin to use Ruby’s DBI  
> rather than just steeling the underlying ActiveRecord connections?

Kind regards

```
robert
```

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<div class="post-metadata">

**Author:** ![bizzz](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/bbe5ce/32.png) [@bizzz](https://www.ruby-forum.com/u/bizzz)\
**Post date:** [November 7, 2006, 10:46am UTC](https://www.ruby-forum.com/t/active-record-speed/74516/3 "2006-11-07T10:46:39Z")

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On 10/30/06, Andrew L. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> I come from a Perl DBI and JDBC world, and would like to use  
> prepared statements. So I’ve gotten the underlying Mysql  
> connection (using ActiveRecord::Base.connection.raw\_connection).

My guess is that prepared statements are indeed the source of your  
performance problems. IIRC, ActiveRecord does not cache prepared  
statements by default (and if there’s an option for it, I do not know  
of it) so you’re essentially calling prepare once for each INSERT! For  
most Rails applications this is a space for improvement but not a show  
stopper. For importing loads of data, it’s simply unacceptable.

> I get an error on the execute statement. It claims I need  
> to send it 4 parameters.

Unlike in perl (which I’m assuming you’re used to from the symptoms  
here), arrays and lists are not _quite_ the same thing in Ruby. When  
you call stmt.execute(bind\_params), you are not passing a list of four  
parameters to execute (as you might expect), but just one parameter  
that is an array. Fortunately, Ruby does provide a mechanism for  
“splatting” an array into a list of parameters:

stmt.execute(\*bind\_params) # note the star

Let us know if this takes care of it for you!

Jacob F.

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**Author:** ![bizzz](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/b/bbe5ce/32.png) [@bizzz](https://www.ruby-forum.com/u/bizzz)\
**Post date:** [November 7, 2006, 10:46am UTC](https://www.ruby-forum.com/t/active-record-speed/74516/4 "2006-11-07T10:46:47Z")

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Robert, Jaccob you two nailed it. Thanks a bunch.  
It’s subtle, the difference between a list and an array  
especially with a perl background.

Thanks!

Andy