GSI overloading technique in DynamoDB - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a Global Secondary Index (GSI) in DynamoDB?

A GSI is an index with a partition key and optional sort key that can be different from the base table's keys. It allows querying data efficiently using alternate keys.

intermediate

What does the GSI overloading technique mean?

It means using a single GSI to serve multiple query patterns by cleverly designing attribute values to store different types of data in the same index.

intermediate

Why use GSI overloading in DynamoDB?

To reduce the number of GSIs needed, saving costs and simplifying table design while supporting multiple query types on one index.

advanced

How do you differentiate data types in a GSI overloading technique?

By prefixing or encoding attribute values with type identifiers or categories, so queries can filter or sort based on these markers.

advanced

Give an example of a GSI overloading pattern.

Using a GSI with a partition key like 'TYPE#User' or 'TYPE#Order' to store different entity types in the same index, enabling queries by type prefix.

What is the main benefit of using GSI overloading in DynamoDB?

A Avoid using partition keys

B Increase table size

C Make queries slower

D Reduce the number of GSIs needed

GSI overloading helps reduce the number of GSIs needed by combining multiple query patterns into one index.

In GSI overloading, how do you separate different data types in the same index?

A Use different table names

B Prefix attribute values with type identifiers

C Use multiple partition keys in the base table

D Create multiple GSIs for each type

Prefixing attribute values with type identifiers allows the same GSI to store different data types and be queried accordingly.

Which attribute(s) can differ between a base table and a GSI in DynamoDB?

A Partition key only

B Sort key only

C Partition key and sort key

D Neither can differ

Both partition key and sort key can be different in a GSI compared to the base table.

What is a potential downside of GSI overloading?

A Complexity in designing attribute values

B Increased cost due to many GSIs

C Cannot query by partition key

D Slower base table writes

GSI overloading requires careful design of attribute values to distinguish data types, which can add complexity.

Which DynamoDB feature allows querying data using alternate keys?

A Global Secondary Index (GSI)

B Local Secondary Index (LSI)

C Primary Key

D Streams

Global Secondary Indexes allow querying data using keys different from the base table's primary key.

Explain the GSI overloading technique and why it is useful in DynamoDB.

Think about how one index can serve many purposes by encoding data cleverly.

Describe how you would design attribute values to support GSI overloading.

Consider how you can tag data so queries know what they are looking for.