### Examples

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_sources/sql/start-transaction.rst.txt

Examples of how to use the START TRANSACTION command with different options.

```sql
START TRANSACTION;
START TRANSACTION ISOLATION LEVEL REPEATABLE READ;
START TRANSACTION READ WRITE;
START TRANSACTION ISOLATION LEVEL READ COMMITTED, READ ONLY;
START TRANSACTION READ WRITE, ISOLATION LEVEL SERIALIZABLE;
```

--------------------------------

### IO Plan and JSON Format Example

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_static/sql/explain.rst

An example showing how to get the IO plan in JSON format for an INSERT statement.

```none
presto:hive> EXPLAIN (TYPE IO, FORMAT JSON) INSERT INTO test_nation SELECT * FROM nation WHERE regionkey = 2;
                Query Plan
-----------------------------------
 {
   "inputTableColumnInfos" : [ { 
     "table" : { 
       "catalog" : "hive", 
       "schemaTable" : { 
         "schema" : "tpch", 
         "table" : "nation" 
       }
     },
     "columns" : [ { 
       "columnName" : "regionkey", 
       "type" : "bigint", 
       "domain" : { 
         "nullsAllowed" : false,

```

--------------------------------

### JVM Config Example

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_sources/installation/deployment.rst.txt

A recommended starting point for the etc/jvm.config file.

```none
-server
-Xmx16G
-XX:+UseG1GC
-XX:G1HeapRegionSize=32M
-XX:+UseGCOverheadLimit
-XX:+ExplicitGCInvokesConcurrent
-XX:+HeapDumpOnOutOfMemoryError
-XX:+ExitOnOutOfMemoryError
```

--------------------------------

### Start Kafka Server

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_sources/connector/kafka-tutorial.rst.txt

Starts the Kafka server.

```none
$ bin/kafka-server-start.sh config/server.properties
[2013-04-22 15:01:47,028] INFO Verifying properties (kafka.utils.VerifiableProperties)
[2013-04-22 15:01:47,051] INFO Property socket.send.buffer.bytes is overridden to 1048576 (kafka.utils.VerifiableProperties)
...
```

--------------------------------

### Start Presto

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_sources/connector/kafka-tutorial.rst.txt

Command to start the Presto server.

```bash
$ bin/launcher start
```

--------------------------------

### GET /v1/node Example Response

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_sources/rest/node.rst.txt

Example response for the GET /v1/node endpoint, showing a single node with no failures.

```http
HTTP/1.1 200 OK
Vary: Accept
Content-Type: text/javascript

[
   {
      "uri":"http://10.209.57.156:8080",
      "recentRequests":25.181940555111073,
      "recentFailures":0.0,
      "recentSuccesses":25.195472984170983,
      "lastRequestTime":"2013-12-22T13:32:44.673-05:00",
      "lastResponseTime":"2013-12-22T13:32:44.677-05:00",
      "age":"14155.28ms",
      "recentFailureRatio":0.0,
      "recentFailuresByType":{}
   }
]
```

--------------------------------

### GET /v1/node Example Response with Errors

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_sources/rest/node.rst.txt

Example response for the GET /v1/node endpoint, showing a node experiencing errors.

```http
HTTP/1.1 200 OK
Vary: Accept
Content-Type: text/javascript

[
   {
      "age": "4.45m",
      "lastFailureInfo": {
          "message": "Connect Timeout",
          "stack": [
              "org.eclipse.jetty.io.ManagedSelector$ConnectTimeout.run(ManagedSelector.java:683)",
              ....
              "java.lang.Thread.run(Thread.java:745)"
          ],
          "suppressed": [],
          "type": "java.net.SocketTimeoutException"
      },
      "lastRequestTime": "2017-08-05T11:53:00.647Z",
      "lastResponseTime": "2017-08-05T11:53:00.647Z",
      "recentFailureRatio": 0.47263053472046446,
      "recentFailures": 2.8445543205610617,
      "recentFailuresByType": {
          "java.net.SocketTimeoutException": 2.8445543205610617
      },
      "recentRequests": 6.018558073577414,
      "recentSuccesses": 3.1746446343010297,
      "uri": "http://172.19.0.3:8080"
   }
]
```

--------------------------------

### Show Tables

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_static/connector/kafka-tutorial.rst

SQL command to list tables in the current catalog and schema.

```sql
presto:tpch> SHOW TABLES;
  Table
----------
 customer
 lineitem
 nation
 orders
 part
 partsupp
 region
 supplier
(8 rows)
```

--------------------------------

### GET /v1/node/failed Example Response

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_sources/rest/node.rst.txt

Example response for the GET /v1/node/failed endpoint, listing nodes that have failed the last heartbeat check.

```http
HTTP/1.1 200 OK
Vary: Accept
Content-Type: text/javascript

[
   {
      "age": "1.37m",
      "lastFailureInfo": {
          "message": "Connect Timeout",
          "stack": [
              "org.eclipse.jetty.io.ManagedSelector$ConnectTimeout.run(ManagedSelector.java:683)",
              ....
              "java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)",
              "java.lang.Thread.run(Thread.java:745)"
          ],
          "suppressed": [],
          "type": "java.net.SocketTimeoutException"
      },
      "lastRequestTime": "2017-08-05T11:52:42.647Z",
      "lastResponseTime": "2017-08-05T11:52:42.647Z",
      "recentFailureRatio": 0.22498784153043677,
      "recentFailures": 20.11558290058638,
      "recentFailuresByType": {
          "java.net.SocketTimeoutException": 20.11558290058638
      },
      "recentRequests": 89.40742203558189,
      "recentSuccesses": 69.30583024727453,
      "uri": "http://172.19.0.3:8080"
   }
]
```

--------------------------------

### json_array_length function example

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_sources/functions/json.rst.txt

Example showing how to get the length of a JSON array.

```sql
SELECT json_array_length('[1, 2, 3]');
```

--------------------------------

### Start Presto CLI

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_sources/connector/kafka-tutorial.rst.txt

Command to start the Presto CLI with specific catalog and schema.

```bash
$ ./presto --catalog kafka --schema tpch
```

--------------------------------

### map_top_n_values example

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_sources/functions/map.rst.txt

Example of using map_top_n_values to get top values from a map.

```sql
SELECT map_top_n_values(map(ARRAY['a', 'b', 'c'], ARRAY[1, 2, 3]), 2) --- [3, 2]
```

--------------------------------

### map_keys_by_top_n_values example

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_sources/functions/map.rst.txt

Example of using map_keys_by_top_n_values to get top keys by value.

```sql
SELECT map_top_n_keys_by_value(map(ARRAY['a', 'b', 'c'], ARRAY[2, 1, 3]), 2) --- ['c', 'a']
```

--------------------------------

### Start ZooKeeper and Kafka Server

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/connector/kafka-tutorial.html

Commands to start ZooKeeper and the Kafka server.

```bash
$ bin/zookeeper-server-start.sh config/zookeeper.properties [2013-04-22 15:01:37,495] INFO Reading configuration from: config/zookeeper.properties (org.apache.zookeeper.server.quorum.QuorumPeerConfig) ...
```

```bash
$ bin/kafka-server-start.sh config/server.properties [2013-04-22 15:01:47,028] INFO Verifying properties (kafka.utils.VerifiableProperties) [2013-04-22 15:01:47,051] INFO Property socket.send.buffer.bytes is overridden to 1048576 (kafka.utils.VerifiableProperties) ...
```

--------------------------------

### Example Output

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_static/sql/show-create-table.rst

Example output of the SHOW CREATE TABLE command, showing the CREATE TABLE statement.

```none
              Create Table
-----------------------------------------
 CREATE TABLE tpch.sf1.orders (
    orderkey bigint,
    orderstatus varchar,
    totalprice double,
    orderdate varchar
 )
 WITH (
    format = 'ORC',
    partitioned_by = ARRAY['orderdate']
 )
(1 row)
```

--------------------------------

### ip_subnet_max function examples

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_static/functions/ip.rst

Examples illustrating the use of ip_subnet_max to get the largest IP address in a subnet.

```sql
SELECT ip_subnet_max(IPPREFIX '192.64.0.0/9'); -- {192.127.255.255}
SELECT ip_subnet_max(IPPREFIX '2001:0db8:85a3:0001:0001:8a2e:0370:7334/48'); -- {2001:db8:85a3:ffff:ffff:ffff:ffff:ffff}
```

--------------------------------

### Show Tables Example

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/connector/pinot.html

Example command to show all tables in a Pinot cluster.

```sql
SHOW TABLES from mypinotcluster.default

OR:

SHOW TABLES from mypinotcluster.foo
```

--------------------------------

### ip_prefix_subnets function examples

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_static/functions/ip.rst

Examples for ip_prefix_subnets to get subnets of a given IP prefix with a specified prefix length.

```sql
SELECT IP_PREFIX_SUBNETS(IPPREFIX '192.168.1.0/24', 25); -- [{192.168.1.0/25}, {192.168.1.128/25}]
SELECT IP_PREFIX_SUBNETS(IPPREFIX '2a03:2880:c000::/34', 36); -- [{2a03:2880:c000::/36}, {2a03:2880:d000::/36}, {2a03:2880:e000::/36}, {2a03:2880:f000::/36}]
```

--------------------------------

### Hash counts example

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_static/functions/setdigest.rst

Example of getting a map of Murmur3Hash128 hashed values and their counts from a MinHash structure.

```sql
SELECT hash_counts(x)
```

--------------------------------

### Start ZooKeeper

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_sources/connector/kafka-tutorial.rst.txt

Starts the ZooKeeper server, which is required for Kafka.

```none
$ bin/zookeeper-server-start.sh config/zookeeper.properties
[2013-04-22 15:01:37,495] INFO Reading configuration from: config/zookeeper.properties (org.apache.zookeeper.server.quorum.QuorumPeerConfig)
...
```

--------------------------------

### Example HTTP Request for Statement

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_sources/rest/statement.rst.txt

This snippet shows an example HTTP GET request to retrieve the status or results of a submitted statement.

```http
GET /v1/statement/20140108_110629_00011_dk5x2/1 HTTP/1.1
Host: localhost:8001
User-Agent: StatementClient/0.55-SNAPSHOT
```

--------------------------------

### Example HTTP Connector Configuration

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_sources/release/release-0.54.rst.txt

Configuration properties for mounting the example-http connector as the 'example' catalog.

```none
connector.name=example-http
metadata-uri=http://s3.amazonaws.com/presto-example/v1/example-metadata.json
```

--------------------------------

### Starting Presto Server

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_sources/installation/deployment.rst.txt

Command to start the Presto server after configuration.

```bash
./bin/launcher start
```

--------------------------------

### Example Query Response

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/rest/query.html

This is an example JSON response for the GET /v1/query/{queryId} endpoint, showing detailed statistics about a finished query.

```json
{
  "queryId" : "20131229_211533_00017_dk5x2",
  "session" : {
      "user" : "tobrien",
      "source" : "presto-cli",
      "catalog" : "jmx",
      "schema" : "jmx",
      "remoteUserAddress" : "173.15.79.89",
      "userAgent" : "StatementClient/0.55-SNAPSHOT",
      "startTime" : 1388351852026
  },
  "state" : "FINISHED",
  "self" : "http://10.193.207.128:8080/v1/query/20131229_211533_00017_dk5x2",
  "fieldNames" : [ "name" ],
  "query" : "select name from \"java.lang:type=runtime\"",
  "queryStats" : {
      "createTime" : "2013-12-29T16:17:32.027-05:00",
      "executionStartTime" : "2013-12-29T16:17:32.086-05:00",
      "lastHeartbeat" : "2013-12-29T16:17:44.561-05:00",
      "endTime" : "2013-12-29T16:17:32.152-05:00",
      "elapsedTime" : "125.00ms",
      "queuedTime" : "1.31ms",
      "analysisTime" : "4.84ms",
      "totalTasks" : 2,
      "runningTasks" : 0,
      "completedTasks" : 2,
      "totalDrivers" : 2,
      "queuedDrivers" : 0,
      "runningDrivers" : 0,
      "completedDrivers" : 2,
      "totalMemoryReservation" : "0B",
      "totalScheduledTime" : "5.84ms",
      "totalCpuTime" : "710.49us",
      "totalBlockedTime" : "27.38ms",
      "rawInputDataSize" : "27B",
      "rawInputPositions" : 1,
      "processedInputDataSize" : "32B",
      "processedInputPositions" : 1,
      "outputDataSize" : "32B",
      "outputPositions" : 1
  },
  "outputStage" : { }
}
```

--------------------------------

### Show Tables in Presto

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_sources/connector/kafka-tutorial.rst.txt

Presto CLI command to list tables in the current schema.

```sql
SHOW TABLES;
```

--------------------------------

### Download twistr tool

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_sources/connector/kafka-tutorial.rst.txt

Command to download the twistr tool, used for setting up a live Twitter feed.

```none
$ curl -o twistr https://repo1.maven.org/maven2/de/softwareforge/twistr_kafka_0811/1.2/twistr_kafka_0811-1.2.sh
$ chmod 755 twistr
```

--------------------------------

### find_first_index with index

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_sources/functions/array.rst.txt

Examples of using find_first_index with a starting index to search within an array.

```sql
SELECT find_first(ARRAY[3, 4, 5, 6], 2, x -> x > 0); -- 2
SELECT find_first(ARRAY[3, 4, 5, 6], -2, x -> x > 0); -- 3
SELECT find_first(ARRAY[3, 4, 5, 6], 2, x -> x < 4); -- NULL
SELECT find_first(ARRAY[3, 4, 5, 6], -2, x -> x > 5); -- NULL
```

--------------------------------

### Show Tables

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/connector/kafka-tutorial.html

Presto CLI command to list tables in the current schema.

```sql
presto:tpch> SHOW TABLES;
```

--------------------------------

### find_first with index

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_sources/functions/array.rst.txt

Examples of using find_first with a starting index to search within an array.

```sql
SELECT find_first(ARRAY[3, 4, 5, 6], 2, x -> x > 0); -- 4
SELECT find_first(ARRAY[3, 4, 5, 6], -2, x -> x > 0); -- 5
SELECT find_first(ARRAY[3, 4, 5, 6], 2, x -> x < 4); -- NULL
SELECT find_first(ARRAY[3, 4, 5, 6], -2, x -> x > 5); -- NULL
```

--------------------------------

### Create an empty password file

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_sources/security/password-file.rst.txt

Create an empty password file to get started.

```none
touch password.db
```

--------------------------------

### JVM Config Example

Source: https://github.com/prestodb/prestodb.github.io/blob/source/website/static/docs/0.291/_sources/router/deployment.rst.txt

An example configuration for the Java Virtual Machine settings.

```none
-ea
-XX:+UseG1GC
-XX:G1HeapRegionSize=32M
-XX:+UseGCOverheadLimit
-XX:+ExplicitGCInvokesConcurrent
-Xmx12G
```