Amazon Athena

Amazon Athena is an interactive query service that utilizes schema-on-read, allowing you to run ad-hoc SQL-like queries on data from a range of sources.

Results are returned in seconds, and you are billed only for the compute time used and any existing storage costs.
Athena can query many forms of structured, semi-structured, and unstructured data in S3.

Tables are defined in a data catalog and are applied on read. Athena allows SQL queries against data stored on S3, through the schema-on-read tables.

Athena can be used to query various AWS logs, including flow logs and ELB logs.
No data is modified by Athena, and output can be sent to visualization tools.