Create a search…then speed it up by a factor of 50!

One great way to implement a basic search is to put all your data fields into one big array and then perform the search on this one field. Let’s say, you’ve got a Customer model. Open up customer.rb (in app/models/) and write this few lines of code:

To pick only the searched items we’re creating a scope to which we’re passing the search argument. You can add a function, which will turn all separate fields into one big keywords array.

Now, open up your Controller (CustomersController.rb)

If desired, you can add some validation for cases if no search parameter is provided.

This approach won’t yield you amazon like results, but can bring one pretty far.

Step up the game

If you want to make one little step further and do not want to bother with “heavy industry” tools like ElasticSearch, then you can utilize PostgreSQL’s awesome built in indexing features. This approach requires a bit more setup, than the first one, but once you follow those steps, it will appear straight forward.

The main goal is to write our custom SQL query. In the end what we want to achieve is something like this:

Using rails syntax this would mean we need a query like this:

To create this query and keep things clean I’m using an extra class (models/customer_search_term.rb):

Now we need this helper function, “build_for_name_search” (I’ll omit the first one for now).

This function does nothing else rather than building the string for our SQL query. You can verify it by examining the variables – @where_clause is a string, while @where_args is a hash.

Finally, let’s build our controller:

We’re almost there. This search works, but it’s still a bit slow (see below for speed results).

Now we need to create custom indexes on those tables. We will stick to old up and down migration methods, since rails won’t understand our custom SQL migration if we’d stick to “change”.

It’s important to use “varchar_pattern_ops”, since we are not using an exact match, but instead using a like operator. Now, if we fire up rails dbconsole and perform  EXPLAIN ANALYZE on both methods, we can see the difference.Ama

This was the original result:

After spicing things up:

This is an increase by a factor of 243!