CODEWITHSUNDEEP
iphonedatabasesearchcore-datansdictionary
Sagiftw
Sagiftw

Reputation: 1658

How to create a quick seach-as-you-type mechanism for a very large Core Data database?

I am trying to implement a quick search as-you-type mechanism.

In my current implementation, when the user launches the app for the first time, he has to wait a little bit for a downloading process to complete. During that time, information about the 20,000 products that the app sells is being downloaded. Each product is represented by an instance of NSManagedObject and is added to a Core Data database.

The real problem is the way to use those products. After the user launches the app once again (not the first time), the products need to be loaded to memory so the search would be quick. In order to do that, I loop over the entire database and create an instance of NSDictionary for each product that contains its information, because it is much easier to use dictionary objects in my program to retrieve information about the product.

Because the dictionaries are stored in the memory and therefore the search process is very quick, but iterating over the 20,000 objects (onces per launch) and creating dictionaries takes a lot of time (about a minute), so that solution is not good.

I thought about another way to reach the quick-search goal: Fetching objects from the database after each letter has been typed. But I do not know how fast it would be.

What is the recommended way to do that?

Thanks, Sagiftw

Upvotes: 1

Views: 164

Answers (1)

hburde
hburde

Reputation: 1441

I have a similar feature in my app but have considerable less records. I have indices on all search fields and create as simple (inexpensive) sql querys (NSPredicate)as possible from the input (2nd fetchedResultsController only for searching). The result set contains the 'search items'. This is at least fast enough for around 1000 entries (test data size) with a random distribution of text type search keys. Its possible a good idea to fetch in the background to prevent the gui from being unresponsive.

Upvotes: 2

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