Lambda trigger amount limit

Is there any information on how many would I need to add to reach the 20KB limit? Also, does the SNS topics allow concurrent invocation if I have multiple objects being added to multiple buckets at the same time?

Also, would it be possible to implement something like this: https://stackoverflow.com/questions/46603701/the-final-policy-size-20539-is-bigger-than-the-limit-20480

So I could maybe allow all bucket with a certain prefix?

In my environment, I have three access permissions. It is about 1.6 KB in this state. So, a simple calculation suggests that it could be set up for about 36 pieces.

Also, does the SNS topics allow concurrent invocation if I have multiple objects being added to multiple buckets at the same time?

Yes, they are activated at the same time.

Also, would it be possible to implement something like this: https://stackoverflow.com/questions/46603701/the-final-policy-size-20539-is-bigger-than-the-limit-20480 So I could maybe allow all bucket with a certain prefix?

I was a little curious, so I added the following "Function resource-based policy" and verified it. For this policy, Lambda was not triggered when the file was created in S3. In other words, you cannot set a prefix to allow all buckets. The ARN of the S3 bucket had to be set correctly.

{
  "Version": "2012-10-17",
  "Id": "default",
  "Statement": [
    {
      "Sid": "test",
      "Effect": "Allow",
      "Principal": {
        "Service": "s3.amazonaws.com"
      },
      "Action": "lambda:InvokeFunction",
      "Resource": "arn:aws:lambda:ap-northeast-1:<AWS Account ID>:function:test",
      "Condition": {
        "StringEquals": {
          "AWS:SourceAccount": "<AWS Account ID>"
        },
        "ArnLike": {
          "AWS:SourceArn": "arn:aws:s3:::kobayashi-*"
        }
      }
    }
  ]
}

Could you technically then set:

"ArnLike": { "AWS:SourceArn": "arn:aws:s3:::*" } And that would work for all s3, no exception?