jamwt•3w ago

no need to use promise.all(). and I'd

no need to use promise.all(). and I'd keep your batches between 100-1000

7 Replies

Mark L•3w ago

So instead of this:

    await Promise.all(
      data.map(async (row) => {
        try {
          await ctx.db.insert('table', row);
        } catch (error) {
          ...
        }
      })
    );

    await Promise.all(
      data.map(async (row) => {
        try {
          await ctx.db.insert('table', row);
        } catch (error) {
          ...
        }
      })
    );

I should just do:

data.map(async (row) => {
  try {
    await ctx.db.insert('table', row);
  } catch (error) {
    ...
  }
})

data.map(async (row) => {
  try {
    await ctx.db.insert('table', row);
  } catch (error) {
    ...
  }
})

? or a for of loop?

jamwtOP•3w ago

yeah, that works! the reason is the inserts aren't actually doing I/O. they're just queuing up writes that will all be flushed if/when the mutation succeeds I'd prefer just a simple for loop, yeah

Mark L•3w ago

Thanks @Jamie ! It's quite confusing when you get started with Convex, that you are writing code that seems like it would be extremely inefficient, but gets translated into something that runs fast 😅

jamwtOP•3w ago

yeah. I mean, this detail is a little subtle. but if you're querying data (db.query(...)), making things concurrent with promise.all does help, b/c that might actually do network I/O if values aren't in the cache but for writes (insert/update etc) there is no need to do this, since they're not actually async under the covers

Mark L•3w ago

good to know! Thanks!

erquhart•3w ago

Does this mean insert/update don’t actually need to be awaited in general?

jamwtOP•3w ago

I would still await them to be safe. Otherwise, our protection about un awaited promises might kick in.

no need to use promise.all(). and I'd

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