Today, we’re excited to announce that Amazon Athena supports AWS Glue Data Catalog partition indexes to optimize query planning and reduce query runtime. When you query a table containing a large number of partitions, Athena retrieves the available partitions from the AWS Glue Data Catalog and determines which are required by your query. As new partitions are added, the time needed to retrieve the partitions increases and can cause query runtime to increase. AWS Glue Data Catalog allows customers to create partition indexes which reduce the time required to retrieve and filter partition metadata on tables with tens and hundreds of thousands of partitions.
Source:: Amazon AWS