amazon web services - Dynamodb scan in sorted order

Question

Hi I have a dynamodb table. I want the service to return me all the items in this table and the order is by sorting on one attribute.

Do I need to create a global secondary index for this? If that is the case, what should be the hash key, what is the range key? (Note that query on gsi must specify a "EQ" comparator on the hash key of GSI.)

Thanks a lot!

Erben

Answer 1

If you know the HashKey, then any query will return the items sorted by Range key. From the documentation:

Query results are always sorted by the range key. If the data type of the range key is Number, the results are returned in numeric order. Otherwise, the results are returned in order of UTF-8 bytes. By default, the sort order is ascending. To reverse the order, set the ScanIndexForward parameter set to false.

Now, if you need to return all the items, you should use a scan. You cannot order the results of a scan.

Another option is to use a GSI (example). Here, you see that the GSI contains only HashKey. The results I guess will be in sorted order of this key (I didn't check this part in a program yet!).