Indexes

Local Seconday Index (LSI)

• This provides an Alternative Sort Key for your table, but with same partition key of the base table.

• This sort key can be a scalar attribute of type String, Binary or Number of base table.

• Can have upto 5 LSI per table.

• Must be defined at table creation time.

• It may contain some or all attribute from base table.

• LSI uses capacity units of base table.

Global Seconday Index (GSI)

• Alternative Primary key from the base table.

• This index enables to speed up the queries based on non-key attributes.

• Index key consists of scalar attributes from base table of type Number, String or Binary.

• Attribute projections can be some or all attributes of the base table.

• Must provision RCU and WCU for the index (kind of like a new table).

• They can be created/modified after table creation.

Throttling

GSI Index

• If writes are throttled on GSI, then the main table will be throttled even if there is enough capacity on main table.

LSI Index

• No need for special consideration of throttling.

• They use WCU and RCU of main table.