[Presto](https://prestosql.io/) is a distributed SQL query engine optimized for ad-hoc analysis at interactive speed. It supports standard ANSI SQL, including complex queries, aggregations, joins, and window functions. It has a connector architecture to query data from many data sources.

This document describes how to set up Presto to query YugabyteDB's YCQL tables.

## 1. Start local cluster

Follow the [Quick start](/stable/quick-start/macos/) instructions to run a local YugabyteDB cluster. Test YugabyteDB's Cassandra-compatible API, as [documented](/stable/quick-start/explore/ycql/) so that you can confirm that you have a Cassandra-compatible service running on `localhost:9042`. Ensure that you have created the keyspace and table, and inserted sample data as described there.

## 2. Download and configure Presto

Detailed steps are documented [here](https://prestosql.io/docs/current/installation/deployment.html).
The following are the minimal steps for getting started:

```sh
$ wget https://repo1.maven.org/maven2/io/prestosql/presto-server/309/presto-server-309.tar.gz
```

```sh
$ tar xvf presto-server-309.tar.gz
```

```sh
$ cd presto-server-309
```

### Create the “etc”, “etc/catalog”, and “data” directory inside the installation directory

```sh
$ mkdir etc
```

```sh
$ mkdir etc/catalog
```

```sh
$ mkdir data
```

### Create node.properties file - replace <username> below

```sh
$ cat > etc/node.properties
```

```cfg
node.environment=test
node.id=ffffffff-ffff-ffff-ffff-ffffffffffff
node.data-dir=/Users/<username>/presto-server-309/data
```

Press Ctrl-D after you have pasted the file contents.

### Create jvm.config file

```sh
$ cat > etc/jvm.config
```

```cfg
-server
-Xmx6G
-XX:+UseG1GC
-XX:G1HeapRegionSize=32M
-XX:+UseGCOverheadLimit
-XX:+ExplicitGCInvokesConcurrent
-XX:+HeapDumpOnOutOfMemoryError
-XX:+ExitOnOutOfMemoryError
```

Press Ctrl-D after you have pasted the file contents.

### Create config.properties file

```sh
$ cat > etc/config.properties
```

```cfg
coordinator=true
node-scheduler.include-coordinator=true
http-server.http.port=8080
query.max-memory=4GB
query.max-memory-per-node=1GB
discovery-server.enabled=true
discovery.uri=http://localhost:8080
```

Press Ctrl-D after you have pasted the file contents.

### Create log.properties file

```sh
$ cat > etc/log.properties
```

```cfg
io.prestosql=INFO
```

Press Ctrl-D after you have pasted the file contents.

### Configure Cassandra connector to YugabyteDB

Create the Cassandra catalog properties file in `etc/catalog` directory.
Detailed instructions are [here](https://prestosql.io/docs/current/connector/cassandra.html).

```sh
$ cat > etc/catalog/cassandra.properties
```

```cfg
connector.name=cassandra
cassandra.contact-points=127.0.0.1
```

Press Ctrl-D after you have pasted the file contents.

## 3. Download Presto CLI

```sh
$ cd ~/presto-server-309/bin
```

```sh
$ wget https://repo1.maven.org/maven2/io/prestosql/presto-cli/309/presto-cli-309-executable.jar
```

Rename the JAR file to `presto`. It is meant to be a self-running binary.

```sh
$ mv presto-cli-309-executable.jar presto && chmod +x presto
```

## 4. Launch Presto server

```sh
$ cd ~/presto-server-309
```

To run in foreground mode:

```sh
$ ./bin/launcher run
```

To run in background mode:

```sh
$ ./bin/launcher start
```

## 5. Test Presto queries

Use the presto CLI to run ad-hoc queries:

```sh
$ ./bin/presto --server localhost:8080 --catalog cassandra --schema default
```

Start using `myapp`:

```sql
presto:default> use myapp;
```

```output
USE
```

Show the tables available:

```sql
presto:myapp> show tables;
```

```output
 Table
-------
 stock_market
(1 row)
```

Describe a particular table:

```sql
presto:myapp> describe stock_market;
```

```output
    Column     |  Type   | Extra | Comment
---------------+---------+-------+---------
 stock_symbol  | varchar |       |
 ts            | varchar |       |
 current_price | real    |       |
(3 rows)
```

### Query with filter

```sql
presto:myapp> select * from stock_market where stock_symbol = 'AAPL';
```

```output
 stock_symbol |         ts          | current_price
--------------+---------------------+---------------
 AAPL         | 2017-10-26 09:00:00 |        157.41
 AAPL         | 2017-10-26 10:00:00 |         157.0
(2 rows)
```

### Query with aggregates

```sql
presto:myapp> select stock_symbol, avg(current_price) from stock_market group by stock_symbol;
```

```output
 stock_symbol |  _col1
--------------+---------
 GOOG         | 972.235
 AAPL         | 157.205
 FB           | 170.365
(3 rows)
```