OR-query on multiple attributes in Amazon DynamoDB

Question

I have a table like this:

Transports

id (PK)	createDt	shipperId	carrierId	consigneeId
1	23	contact3	contact2	contact1
2	24	contact1	contact2	contact3
3	28	contact3	contact2	contact4

My access pattern is:

• find all transports where a contact was either shipper, carrier or consignee sorted by createDt. Eg entering contact1 should return records 1, 2.

How can I do this in DyanomoDB?

I thought about creating a GSI. But then I need to create a separate GSI for each column, which would mean I need to join the query results on the columns myself. Perhaps there is an easier way.

Answer 1

I'd create a GSI on the table and split your single record up into multiple ones. That would make writes slightly more complex, because you write multiple entities, but I'd do something like this:

PK	SK	type	GSI1PK	GSI1SK	other attributes
TRANSP#1	TRANSP#1	transport			createDt, (shipperId, carrierId, consigneeId)...
TRANSP#1	CONTACT#SHIP	shipper-contact	CONTACT#contact3	TRANSP#1#SHIP	...
TRANSP#1	CONTACT#CARR	carrier-contact	CONTACT#contact2	TRANSP#1#CARR	...
TRANSP#1	CONTACT#CONS	consignee-contact	CONTACT#contact1	TRANSP#1#CONS	...

• To get all information about a given Transport ID you do a query with PK=TRANSP#<id>
• To get just the basic information about a given Transport, you can do a GetItem on PK=TRANSP#<id> and SK=TRANSP<id> (You could also duplicate the contact infos here if they're fairly static.)
• To get all transports a contact is involved in, you do a PK=CONTACT#<id> and SK starts with TRANSP on GSI1

If you really need server-side sorting, you might choose a different GSI1SK , maybe prefix it with the dt value, but I'd probably just do that client side.