Transaction/Commit Support

[mjgerace]

Feature Request

For a while now, parse has lacked transaction/commit support. Due to upcoming Postgres support, transactions should be very easy to implement, and provides a much-needed way to secure many api requests in a row with adequate rollback.

No workarounds presented thus far have been nearly as efficient as ACID transactions. I think that if Parse wants to consider itself a top-tier open source package, it needs to have this feature for database integrity.

[joy4eg]

+1 (#2013)

[ellemedit]

Is there no alternative?

[vitaly-t]

Transactions are already used in PostgresStorageAdapter.js, not sure how sufficient though.

[pewh]

Hey, what is the current status? Is there any example how to implement transaction/commit?

[vitaly-t]

@pewh As per my earlier message:

Transactions are already used in PostgresStorageAdapter.js, not sure how sufficient though.

Method .tx (transaction) is used in 6 places there. Not sure how sufficient it is in general, as it requires to understand how the whole thing works, which is a lot.

[trylovetom]

I think mongodb need it, too

[pewh]

.tx is coming from pg-promise (https://github.com/parse-community/parse-server/blob/master/src/Adapters/Storage/Postgres/PostgresClient.js#L17). I guess we can make Parse support transaction/commit like this:

1. Convert Parse.query into pg-promise instance
2. Use batch like this https://github.com/parse-community/parse-server/blob/master/src/Adapters/Storage/Postgres/PostgresStorageAdapter.js#L546-L549

P.s: I'm newbie, so i don't know if it possible or not

[trylovetom]

@pewh I think we need any query or update function support transaction/commit.

[trylovetom]

@pewh Let's do it ?

[manjukas]

Is it possible to have transactions with mongo, as mongodb doesn't really support multi document transactions?

Optimistic locking would be nice for Object class. Just need a integer type attribute, which gets incremented each time the object is saved. And save will fail if someone else has modified since the last read. This can be consistently implemented across Mongo and Postgres.

[flovilmart]

If you need a transactional RDBMS, you should not use MongoDB in the first place, and if you really need transactions, baking it into parse-server may prove painful and inefficient (i.e., you should probably not use parse-server if you intend to have a highly transactional system, I would personally not use it for that).

[heresmyinfo]

@flovilmart We have an application that is currently based on Parse, but needs the reliability of transactional support. When you say "painful and inefficient", are you referring to high-performance or difficulty in implementation? We're not as concerned with performance as reliability. If it's just performance you are referring to, how much effort do you think it would take to implement transactional logic now that we have switched to Postgres (which is working great)? Do you have anyone you can refer us to?

[charleskoehl]

We also have an application based on Parse. Recently, it became necessary to use transactions to support a ledger of user loyalty rewards points. We are considering these options:

1. Switch to Firebase and use its new database, "Firestore," (in beta; has documents organized into collections and supports multi-document transactions and batch writes), and "Cloud Functions" (in beta; a cross between AWS Lambda and Parse Cloud Functions), which appears to duplicate many of the features of Parse
2. Ask the ParseServer maintainers to support transactions using Fawn or similar.

@flovilmart: If someone were to create a PR to add transaction support using Fawn, would you consider merging it, or is that a feature that you don't want to support period?