5 ms·

If you have a database access layer then structuring your application shouldn't be that different. I wouldn't deal with the database directly unless I had a rea

If you have a database access layer then structuring your application shouldn't be that different. I wouldn't deal with the database directly unless I had a really good reason or the abstraction layer didn't support the query I was trying to run.

ciberado 4y ago
DynamoDB is amazing, but not very flexible once you have designed your database. No abstraction layer will allow you to run queries ad-hoc in a performant way.
- whalesalad 4y ago
  It’s true. 400kb max item size, too. 1mb max query size I believe. Good luck grabbing a shit load of data at once without a parallel scan. Dynamo is a precision tool and it’s great at those specific workloads but it’s not a one size fits all by any means.
  - deleted 4y ago
    [deleted]
  - shepherdjerred 4y ago
    400kb is the max item size, the pattern to get around that is to store objects in S3 and URLs/keys to those objects in DDB
- eatonphil 4y ago
  > No abstraction layer will allow you to run queries ad-hoc in a performant way. Depends on the size of the data. Run analytics queries (i.e. things that return summary data not all rows) on 10GB of data through clickhouse or duckdb or datafusion and they'll generally return in milliseconds.
  - nightpool 4y ago
    What does this have to do with DynamoDB? The point is that once you've gotten your data into DynamoDB, you're strongly limited in how you can use it until you load it into something else.
    - eatonphil 4y ago
      I didn't see an obvious connection between the two sentences.
manigandham 4y ago
An access layer doesn't change your access patterns, which is what actually determines the database model to use. DynamoDB (and other similar key/value stores) make very big trade-offs for speed and scale that most applications don't need.
Dobbs 4y ago
DynamoDB usage is heavily based around correctly structuring your keys. Allowing you to do things like query sub-sets easily. This in turn means you need to know what your usage patterns will be like so you can correctly structure your keys. God help you if you need to make major changes to this down the road. Database Access Layer can't do this for you, that just isn't what they do.

ciberado 4y ago

DynamoDB is amazing, but not very flexible once you have designed your database. No abstraction layer will allow you to run queries ad-hoc in a performant way.

whalesalad 4y ago
It’s true. 400kb max item size, too. 1mb max query size I believe. Good luck grabbing a shit load of data at once without a parallel scan. Dynamo is a precision tool and it’s great at those specific workloads but it’s not a one size fits all by any means.
- deleted 4y ago
  [deleted]
- shepherdjerred 4y ago
  400kb is the max item size, the pattern to get around that is to store objects in S3 and URLs/keys to those objects in DDB
eatonphil 4y ago
> No abstraction layer will allow you to run queries ad-hoc in a performant way. Depends on the size of the data. Run analytics queries (i.e. things that return summary data not all rows) on 10GB of data through clickhouse or duckdb or datafusion and they'll generally return in milliseconds.
- nightpool 4y ago
  What does this have to do with DynamoDB? The point is that once you've gotten your data into DynamoDB, you're strongly limited in how you can use it until you load it into something else.
  - eatonphil 4y ago
    I didn't see an obvious connection between the two sentences.

manigandham 4y ago

An access layer doesn't change your access patterns, which is what actually determines the database model to use. DynamoDB (and other similar key/value stores) make very big trade-offs for speed and scale that most applications don't need.

Dobbs 4y ago

DynamoDB usage is heavily based around correctly structuring your keys. Allowing you to do things like query sub-sets easily. This in turn means you need to know what your usage patterns will be like so you can correctly structure your keys. God help you if you need to make major changes to this down the road. Database Access Layer can't do this for you, that just isn't what they do.