What is global secondary index?

A global secondary index contains a selection of attributes from the base table, but they are organized by a primary key that is different from that of the table. The index key does not need to have any of the key attributes from the table. It doesn’t even need to have the same key schema as a table.

What is local secondary index in AWS?

A local secondary index maintains an alternate sort key for a given partition key value. A local secondary index also contains a copy of some or all of the attributes from its base table. The data in a local secondary index is organized by the same partition key as the base table, but with a different sort key.

What is a GSI DynamoDB?

AWS DynamoDB supports two types of indexes: Global Secondary Index (GSI) and Local Secondary Index (LSI). It is deemed “global” because queries on the index can access the data across different partitions of the base table. It can viewed as a different table that contains attributes based on the base table.

Is GSI unique?

A GSI does not need to have a sort key element; we may have only a partition key (may not be unique). Unlike the primary key on a table, a GSI index does not require the indexed attributes to be unique.

What is a local secondary index?

Local secondary index — An index that has the same partition key as the base table, but a different sort key. A local secondary index is “local” in the sense that every partition of a local secondary index is scoped to a base table partition that has the same partition key value.

What is difference between GSI and LSI DynamoDB?

LSI – allows you to perform a query on a single Hash-Key while using multiple different attributes to “filter” or restrict the query. GSI – allows you to perform queries on multiple Hash-Keys in a table, but costs extra in throughput, as a result.

Why do we use secondary index in Teradata?

A Secondary Index (SI) is an alternate data access path. It allows you to access the data without having to do a full-table scan. You can drop and recreate secondary indexes dynamically, as they are needed.

How many GSI can a table have?

20
Each table in DynamoDB can have up to 20 global secondary indexes (default quota) and 5 local secondary indexes.

What is global index and local index in DynamoDB?

Amazon DynamoDB supports two types of secondary indexes: Global secondary index—An index with a partition key and a sort key that can be different from those on the base table. Local secondary index—An index that has the same partition key as the base table, but a different sort key.

Can we update GSI in DynamoDB?

1 Answer. According to UpdateTable API it is only possible to create and delete GSI. So to update the current GSI, the old GSI needs to be deleted and recreated again.

What is Dynamo index?

DynamoDB uses indexes for primary key attributes to improve accesses. They accelerate application accesses and data retrieval, and support better performance by reducing application lag.