Overhead of insert notifications

[johnjohndoe]

I noticed that multiple notifications are sent when bulkInsert is used. I figured out this because you iterating each ContentValue and run an individual transaction insert on the item.

@Override
public int bulkInsert(Uri uri, ContentValues[] values) {
    int numValues = values.length;
    SQLiteDatabase mDb = mOpenHelper.getWritableDatabase();
    mDb.beginTransactionWithListener(this);
    try {
        for (int i = 0; i < numValues; i++) {
            Uri result = insertInTransaction(uri, values[i]);
            if (result != null) {
                mNotifyChange = true;
            }
            mDb.yieldIfContendedSafely();
        }
        mDb.setTransactionSuccessful();
    } finally {
        mDb.endTransaction();
    }

    onEndTransaction();
    return numValues;
}

I cannot see the reason why you are using insert in favor of bulkInsert. Could you please clarify?

[charroch]

It is a rather old piece of code written as I remember with transactions in mind. Could probably be updated for the better

[charroch]

We should probably assign performance testing on the different methods of insertion.

[johnjohndoe]

I definitely recommend using native bulkInsert. It is a huge performance improvement. I learnt this myself in an older project.

[devisnik]

Definitely something we have to look into. 👍

[mr-archano]

I think that moving to native bulkInsert can have its drawbacks: delegating the simple insert we do update or insert under the hood, while using the bulkInsert we could not provide the same feature (in my understanding at least).

[charroch]

yes but upsert is also slow. We should give abilities to insert in different ways. Even to an extreme of getting the DB from contentproviderclient and using the fastest bind method.

[charroch]

but for that I rather be pragmatic and have the setup to test the performances.

[johnjohndoe]

Another workaround would be to queue and squash the notifications which are sent because of the iteration.

[orangeman]

regardless of any performance improvements bulkInsert should only notify content observers once.
That is semantically what it is supposed to do (and a relatively small change). Do we agree on that?

[charroch]

This should definitely be looked into but I can see some reasoning to have it notified in a rather 'frequent' way. Data set change should not have knowledge about implementation of the insert/update. For instance, if we have a 10min write, you could be interested in updating the UI while the insert happens. Now it s either the activity or the content provider that would be responsible for this.

Lets start by doing just one notify URI per bulk insert and then potentially adapt. We could do so by appending the params to the URI. i.e. content://test.com/table?withNotifyEvery=10

[orangeman]

like that idea ..table?notifyEvery=42
gives fine grained control to the user 👍

[juankysoriano]

Closing as this repository is no longer under maintenance and it's about to be archived