dynamo DB pagination last page

Question

Hi Team,

I'm implementing pagination using AWS dynamoDB

I have in my UI 4 buttons 
- first
- next
- previous
- last

I'm getting data by segments of 25 rows to avoid to do full table scan.

when the user click the last button to go directly to the last page,

do I need to do a full table scan for that? or is there a way to get the 25 last rows instead of doing full table scan when we click on the "last" button?

Answer

If your API call is a `Query` then when the user clicks on the last row, you simply set `ScanIndexForward` to `False`, this reverses the order of the `Query`:

https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_Query.html#DDB-Query-request-ScanIndexForward

If you are doing a `Scan` with a limit, then you would need to be a little smarter about things. You would need to break your table up into segments, then use a segmented `Scan` to get the last portion of data, for example:
```
aws dynamodb scan \
    --table-name MusicCollection \
    --total-segments 4 \
    --segment 3
```

https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_Scan.html#DDB-Scan-request-TotalSegments

dynamo DB pagination last page

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