realm-java: Commiting transaction slow

Hi there,

I’m using Android Realm 3.3.1. I load a csv with 800k lines into Realm. To do so I parse the csv, map each line into a Java bean (with a Pools.SynchronizedPool) and inserting every 1000 records into a transaction block.

Here is the block (timeCounter.getStep() is giving me elapsed time since the TimeCounter.get())

final TimeCounter timeCounter = TimeCounter.get();
realm.executeTransaction(new Realm.Transaction() {
    @Override
    public void execute(Realm realm) {
        realm.insert(items);
        long delayToInsert = timeCounter.getStep();
        log.debug("Saved %d items in %d ms", items.size(), delayToInsert);
    }
});
log.debug("Commit transaction in %d ms", timeCounter.getStep());

Here is the result after a while (around 100k inserted) :

Saved 1000 items in 351 ms
Commit transaction in 1180 ms

The insert always takes 300~500ms but the transaction commit is getting bigger and bigger with time. It starts around 500ms (just a bit more than the simple insert), but ends more than 3000ms.

You can see that the monitoring is fine

So I’m a doing something wrong ?

Edit : I tried async transaction, it’s worse Edit2 : Removing @PrimaryKey from the Java Bean helps a lot, but still, transactions commit time is going up slowly (800ms after 250k inserted) Edit3 : No @PrimaryKey, inserting 880k with batch of 5000, starting at 1900ms, finishing at 3000ms. It’s better but not perfect. Still looking for a solution, our csv will grow up