Firestore transaction with multiple get

Question

I\'m trying to run a transaction with a variable number of read operations. I put the read () operations before than update ().

Reading the Firestore doc on https://clou

Answer 1

I was facing the same problem and decided to use a combination of a batched write and "normal" reads. The decision was guided by the fact that I needed to make many reads that did not rely on each other. At first I used a method similar to the one proposed by Derrick above, but it proved not sustainable for may reads. The code dictates that every loop is blocking to the next one. What I did was to batch all the reads to run in parallel with Promise.all The disadvantage of this is that you dont take advantage of transaction features, but since the field I was iterested in was not changing, it made sense Here's my sample code

const batch = firestore().batch()
 const readPromises = invoiceValues.map(val => {
                        return orderCollection(omcId).where(, '', ).get()
                    })

                    return Promise.all(readPromises).then(orderDocs => {
                  //Perform batch operations here
                        return batch.commit()
                     })

This has proven to be more efficient for many reads, while remaining safe since the fields I'm interested in dont change