How does Athena query work?
Athena works directly with data stored in S3. Athena uses Presto, a distributed SQL engine to run queries. It also uses Apache Hive to create, drop, and alter tables and partitions. … Athena uses an approach known as schema-on-read, which allows you to project your schema on to your data at the time you execute a query.
What is the use of Athena?
Athena helps you analyze unstructured, semi-structured, and structured data stored in Amazon S3. Examples include CSV, JSON, or columnar data formats such as Apache Parquet and Apache ORC. You can use Athena to run ad-hoc queries using ANSI SQL, without the need to aggregate or load the data into Athena.
Is Athena an ETL?
We also found Athena to be a robust, powerful, reliable, scalable, and cost-effective ETL tool. The ability to schedule SQL statements, along with support for Create Table As Select (CTAS) and INSERT INTO statements, helped us accelerate our ETL workloads.
What type of SQL is Athena?
Amazon Athena is an interactive query service that makes it easy to analyze data in Amazon S3 using standard SQL. Athena is serverless, so there is no infrastructure to manage, and you pay only for the queries that you run.
Which query language does Athena?
ANSI SQL queries
Amazon Athena supports ANSI SQL queries. Amazon Athena uses Presto, an open source, in-memory, distributed SQL engine, and can handle complex analysis, including large joins, window functions, and arrays.
Can Athena query compressed data?
Athena supports a variety of compression formats for reading and writing data, including reading from a table that uses multiple compression formats.
What is ETL logic?
In computing, extract, transform, load (ETL) is the general procedure of copying data from one or more sources into a destination system which represents the data differently from the source(s) or in a different context than the source(s).
Who is Athena the daughter of?
She was the daughter of Zeus, produced without a mother, so that she emerged full-grown from his forehead. There was an alternative story that Zeus swallowed Metis, the goddess of counsel, while she was pregnant with Athena, so that Athena finally emerged from Zeus.
Can Athena query redshift?
With query services, you can get started fast. You just define a table for your data and start querying using standard SQL. You can also use both services together. If you stage your data on Amazon S3 before loading it into Amazon Redshift, that data can also be registered with and queried by Amazon Athena.
What is data mart in ETL?
Data Marts are subset of the information content of data warehouse that supports the requirements of a particular department or business function. Data mart are often built and controlled by a single department within an enterprise.