Verifying the Presto CLI with a Connector - Presto on Teradata Appliance for Hadoop

Verify that Presto CLI is accessible and working for non-root users. In this guide, Hive is the example connector.

Log in as a non-root user.
1. Enter the following to verify that Presto is in the user $PATH. type presto
  Something similar to the following displays.
```
presto is hashed
(/usr/bin/presto)
```
2. Enter the following to verify that the user can access Presto CLI and run a command. presto --help
  Presto help displays.
```
NAME
presto - Presto interactive console

SYNOPSIS 

presto [--catalog <catalog>]
...
--version 
Display version information and exit
```
Log in to the Presto SQL Engine and use the following to verify the connection. presto --server <FQDN of presto coordinator node>:8285 --catalog hive --schema <schema for hive>--user <user name>
The procedures assume that the <schema for hive> is default.
Logging in to Presto starts a Presto session and displays a Presto prompt. For example:
```
presto:default>
```

As a non-root user, enter the following at the Presto CLI command line prompt to verify that the user can run a Presto CLI command from within a Presto session. presto:default> help

Presto help displays.

Supported commands:
QUIT
EXPLAIN [ ( option [, ...] ) ] <query> 
options: FORMAT { TEXT | GRAPHVIZ } 
TYPE {LOGICAL | DISTRIBUTED }
DESCRIBE <table>
SHOW COLUMNS FROM <table>
SHOW FUNCTIONS
SHOW CATALOGS
SHOW SCHEMAS
SHOW TABLES [LIKE <pattern>]
SHOW PARTITIONS FROM <table> [WHERE ...] [ORDER BY ...] [LIMIT n]
USE [<catalog>.]<schema>

As a non-root user, run the following Presto CLI commands as a test.

presto:default> show catalogs; Something similar to the following displays.

Catalog
-----------
hive 
system
(3 rows)

Query 20160819_144644_00017_72pyd, FINISHED, 1 node
Splits: 1 total, 1 done (100.00%)
0:00 [0 rows, 0B] [0 rows/s, 0B/s]

presto:default> show schemas; Something similar to the following displays.

Schema
--------------------
default
information_schema
(2 rows)

Query 20160819_144755_00020_72pyd, FINISHED, 2 nodes
Splits: 2 total, 2 done (100.00%)
0:00 [15 rows, 185B] [48 rows/s, 598B/s]

Test the Presto CLI table commands.
1. presto:default> create table prestotable (c1 bigint); The table is created, and the following displays.
```
CREATE TABLE
```
2. presto:default> show tables; Something similar to the following displays.
```
Table
---------
prestotable
(1 row)

Query 20160819_144842_00021_72pyd, FINISHED, 2 nodes
Splits: 2 total, 2 done (100.00%)
0:00 [1 rows, 31B] [3 rows/s, 99B/s]
```
3. presto:default> describe prestotable; Something similar to the following displays.
```
Column | Type | Comment
--------+--------+--------- 
c1 | bigint |
(1 row)

Query 20160819_145755_00027_72pyd, FINISHED, 2 nodes
Splits: 2 total, 2 done (100.00%)
0:00 [1 rows, 75B] [2 rows/s, 211B/s]
```
4. presto:default> drop table prestotable; The table is dropped, and the following displays.
```
DROP TABLE
```
  If hive.properties does not contain the entry hive.allow-drop-table=true, the table is not dropped, and the following message displays.
```
Query 20160819_152338_00028_72pyd failed: Access Denied: 
Cannot drop table <user name>.prestotable
```