Error scanning DynamoDB table - node.js

Question

I have the following code that scan's the DynamoDB table and returns a count of the number of people who have the key value test = true. For some reason, this code is not scanning the whole table. Does anyone know why?
var aws = require('aws-sdk');
var config = require('./config.js');
aws.config.update({accessKeyId: config.key, secretAccessKey: config.secret});
aws.config.update({region: 'us-east-1'});
function getItems() {
var db = new aws.DynamoDB.DocumentClient();
db.scan({
TableName : config.db,
}, function(err, data) {
if (err) { console.log(err); return; }
var count = 0;
for (var ii in data.Items) {
ii = data.Items[ii];
if (ii.setRemoveBrandingEmailOptin) {
console.log(ii.test);
count += 1;
}
}
console.log(count);
});
}
getItems();

Answer 1

Per the documentation:
If the total number of scanned items exceeds the maximum data set size
limit of 1 MB, the scan stops and results are returned to the user as
a LastEvaluatedKey value to continue the scan in a subsequent
operation. The results also include the number of items exceeding the
limit.
You shouldn't need to dump the entire table into your application for a simple count anyway. You're doing this in the most inefficient way possible. Try something like this:
db.scan({
TableName : config.db,
Select: 'COUNT',
FilterExpression: "#emailOptInField = :emailOptInValue",
ExpressionAttributeNames: {
"#emailOptInField": "setRemoveBrandingEmailOptin",
},
ExpressionAttributeValues: {
":emailOptInValue": true
}
}, function(err, data) {
if (err) { console.log(err); return; }
var count = data.Count;
console.log(count);
});