Dynamodb Local Secondary Index

On creation of a local secondary index you specify a sort key attribute and its data type.

Dynamodb local secondary index. Using a local secondary index. This is useful for the scenario mentioned in the intro above we still want to partition our data by username but we want to retrieve items by a different attribute amount. The local secondary index model builds on dynamodb s existing key model. Creating a local secondary index.

The naming rules for indexes are the same as those for tables as listed in service account and table quotas in amazon dynamodb. Dynamodb local secondary index. Lets consider some use cases for each model. All local secondary indexes use the read and write capacity units of the underlying table.

When you query records via the local index the operation consumes read capacity units from the table. A name for the index. Let s see a local secondary index in action. Global secondary index is an index that have a partition key and an optional sort key that are different from base table s primary key.

Local secondary indexes are always queried with respect to the table s hash key combined with the range key specified for that index. The type of index to be created either a global secondary index or a local secondary index. Remember that it can only be used on a table with a composite primary key so that rules out our users table from earlier. Dynamodb imposes no one to one relationship requirements on table items and local secondary index items.

Global secondary index gsi and local secondary index lsi. When you perform a write operation create update delete in a table that has a local index there will be two write operations one for the table another for the index. Up until today you would have to select one of the following two primary key options when you create a table. Aws dynamodb supports two types of indexes.

Hash a strongly typed string number or binary value that uniquely identifies each item in a particular table. A local secondary index essentially gives dynamodb tables an additional sort key by which to query data. The local and global index models extend the basic indexing functionality provided by dynamodb. Let s apply it to our userorderstable instead.

Local secondary indexes can be used on a table with a composite primary key to specify an index with the same hash key but a different range key for a table. I recently needed to add a local secondary index to an existing dynamodb table through cloudformation so that i could query objects by the modified column value without scanning. Local secondary indexes consume throughput from the table.