How to load thousands records to Realm correctly?

Question

I'm trying to save about 8000 records into the disk, using Realm, but it's blocking UI. As a result, I use Realm.asyncOpen that performs data saving in background thread.

The problem is 100% CPU usage when I try to save big amount of records this manner.

How to load thousands records to Realm correctly?

Answer 1

Try the way in official demo to save large amounts of data:

DispatchQueue(label: "background").async {
  autoreleasepool {
    // Get realm and table instances for this thread
    let realm = try! Realm()

    // Break up the writing blocks into smaller portions
    // by starting a new transaction
    for idx1 in 0..<1000 {
      realm.beginWrite()

      // Add row via dictionary. Property order is ignored.
      for idx2 in 0..<1000 {
        realm.create(Person.self, value: [
          "name": "\(idx1)",
          "birthdate": Date(timeIntervalSince1970: TimeInterval(idx2))
        ])
      }

      // Commit the write transaction
      // to make this data available to other threads
      try! realm.commitWrite()
    }
  }
}