I have a use-case where i have to query on more than 2 attributes on dynamoDB table. As far as I know, we can only query for upto 2 attributes(partition key, sort key) on DDB table using GSI. is there anything which allows us to query on multiple attribute(say invoiceId, clientId, invoiceStatus) using GSI.
Yes, this is possible, but you need to take into account every access pattern you want to support when you design your table.
This topic has been discussed at re:Invent multiple times. Here is an video from a few years ago https://youtu.be/HaEPXoXVf2k?t=2102 but similar talks have been given on the topic every year.
Two main options are using composite keys or query filters.
Composite keys are very powerful and boil down to making new 'synthetic' keys that simply concatenate other fields that you have in your record and then using these in your GSI.
For example, if you have a client where you want to be able to get all of their open invoice but also want to be able to get an individual invoice you could use clientId as the partition key and concatenate invoiceStatus and invoiceId together as the sort key. You can then use begins_with to only have certain invoice status returned. In this example, you'd get the have to know the invoiceStatus and invoiceId making this not the best example.
The composite key pattern is also useful for dates as you can use greater than or less than to search certain time ranges. However, it is also possible just to directly get the records with the concatenation.
An alternative design is using query filters. This is less efficient as DynamoDB will have to scan every record that matches the partition and sort key. However, the filter can be applied to any attribute and reduces the amount of data transmitted from DynamoDB to your application. This is useful when your main keys are mostly selective, but multiple matches are possible and the filter gets you the rest of the way there.
The other aspect of using a GSI that can help reduce cost is projecting only the attributes you care about. When a record is updated the GSI only updates if one of the projected attributes is updated. By keeping the GSI skinny it makes the previously listed strategies more cost effective.