Vertica

Vertica is an analytical database.

Prerequisites

Ensure that you have the following details before configuring Vertica as a source:

• Database name
• Hostname or IP address
• Port
• Outbound port (5433 is the default port) open in your AWS or Azure security group

Configuring Vertica as a Source

1. On the Datasets page, to the right of Sources in the left panel, click .
2. In the Add Data Source dialog, under Databases, select Vertica.

General

For Name, enter the name to identify the data source in Dremio. The name cannot include the following special characters: /, :, [, or ].

Connection

Name	Description
Host	Vertica host name.
Port	Vertica port number. Defaults to 5433.
Database	Service name of your database.

Authentication

• For Username, enter your Vertica username.
• For Password, enter your Vertica password.

Advanced Options

Specify advanced options with the following settings.

• Record fetch size: Number of records to fetch at once. Set to 0 (zero) to have Dremio automatically decide. By default, this is set to 10.
• Maximum idle connections: The total number of connections allowed to be idle at a given time. By default, this is set to 8.
• Connection idle time (s): The amount of time (in seconds) allowed for a connection to remain idle before the connection is terminated. By default, this is set to 60.
• Query timeout: The amount of time (in seconds) allowed to wait for the results of a query. If this time expires, the connection being used is returned to an idle state.
• Enable external authorization plugin: When enabled, authorizes an external plugin.
• Connection Properties: Connection properties and values for the data source.

Reflection Refresh

You can set the policy that controls how often reflections are scheduled to be refreshed automatically, as well as the time limit after which reflections expire and are removed.

Option	Description
Never refresh	Select to prevent automatic reflection refresh, default is to automatically refresh.
Refresh every	How often to refresh reflections, specified in hours, days or weeks. This option is ignored if Never refresh is selected.
Set refresh schedule	Specify the daily or weekly schedule.
Never expire	Select to prevent reflections from expiring, default is to automatically expire after the time limit below.
Expire after	The time limit after which reflections expire and are removed from Dremio, specified in hours, days or weeks. This option is ignored if Never expire is selected.

Metadata

Specifying metadata options is handled with the following settings.

Dataset Handling

• Remove dataset definitions if underlying data is unavailable (Default).
• If this box is not checked and the underlying files under a folder are removed or the folder/source is not accessible, Dremio does not remove the dataset definitions. This option is useful in cases when files are temporarily deleted and put back in place with new sets of files.

Metadata Refresh

These are the optional Metadata Refresh parameters:

• Dataset Discovery: The refresh interval for fetching top-level source object names such as databases and tables. Set the time interval using this parameter.

  Parameter	Description
  Fetch every	You can choose to set the frequency to fetch object names in minutes, hours, days, or weeks. The default frequency to fetch object names is 1 hour.

• Dataset Details: The metadata that Dremio needs for query planning such as information needed for fields, types, shards, statistics, and locality. These are the parameters to fetch the dataset information.

  Parameter	Description
  Fetch mode	You can choose to fetch only from queried datasets. Dremio updates details for previously queried objects in a source. By default, this is set to Only Queried Datasets.
  Fetch every	You can choose to set the frequency to fetch dataset details in minutes, hours, days, or weeks. The default frequency to fetch dataset details is 1 hour.
  Expire after	You can choose to set the expiry time of dataset details in minutes, hours, days, or weeks. The default expiry time of dataset details is 3 hours.

Privileges

On the Privileges tab, you can grant privileges to specific users or roles. See Access Control for additional information about privileges.

note

All privileges are optional.

1. For Privileges, enter the user name or role name that you want to grant access to and click the Add to Privileges button. The added user or role is displayed in the USERS/ROLES table.
2. For the users or roles in the USERS/ROLES table, toggle the checkmark for each privilege you want to grant on the Dremio source that is being created.
3. Click Save after setting the configuration.

Updating a Vertica Source

To update a Vertica source:

1. On the Datasets page, under Databases in the panel on the left, find the name of the source you want to update.
2. Right-click the source name and select Settings from the list of actions. Alternatively, click the source name and then the at the top right corner of the page.
3. In the Source Settings dialog, edit the settings you wish to update. Dremio does not support updating the source name. For information about the settings options, see Configuring Vertica as a Source.
4. Click Save.

Deleting a Vertica Source

note

If the source is in a bad state (for example, Dremio cannot authenticate to the source or the source is otherwise unavailable), only users who belong to the ADMIN role can delete the source.

To delete a Vertica source, perform these steps:

1. On the Datasets page, click Sources > Databases in the panel on the left.
2. In the list of data sources, hover over the name of the source you want to remove and right-click.
3. From the list of actions, click Delete.
4. In the Delete Source dialog, click Delete to confirm that you want to remove the source.

note

Deleting a source causes all downstream views that depend on objects in the source to break.

Predicate Pushdowns

Dremio delegates the execution of these expressions and functions to the database being queried, often dramatically improving query performance. It can also offload entire SQL queries that include one or more of these expressions and functions.

*, +, -, /, %
<, <=, <>, =, >, >=, !=
AND, NOT, OR, ||
ABS
ACOS
ADD_MONTHS
ASIN
ATAN
ATAN2
AVG
BTRIM
CAST
CBRT
CEIL
CEILING
CHAR_LENGTH
CHARACTER_LENGTH
CONCAT
COS
COT
DATE_ADD
DATE_PART
DATE_SUB
DATE_TRUNC_CENTURY
DATE_TRUNC_DAY
DATE_TRUNC_DECADE
DATE_TRUNC_HOUR
DATE_TRUNC_MICROSECOND
DATE_TRUNC_MILLISECOND
DATE_TRUNC_MINUTE
DATE_TRUNC_MONTH
DATE_TRUNC_QUARTER
DATE_TRUNC_SECOND
DATE_TRUNC_WEEK
DATE_TRUNC_YEAR
DEGREES
E
EXP
EXTRACT_CENTURY
EXTRACT_DAY
EXTRACT_DECADE
EXTRACT_DOW
EXTRACT_DOY
EXTRACT_EPOCH
EXTRACT_HOUR
EXTRACT_MILLENNIUM
EXTRACT_MINUTE
EXTRACT_MONTH
EXTRACT_QUARTER
EXTRACT_SECOND
EXTRACT_WEEK
EXTRACT_YEAR
FLOOR
ILIKE
IS DISTINCT FROM
IS NOT DISTINCT FROM
IS NOT NULL
IS NULL
ISNULL
LAST_DAY
LCASE
LEFT
LENGTH
LIKE
LN
LOCALTIME
LOCALTIMESTAMP
LOCATE
LOG
LOG10
LOWER
LPAD
LTRIM
MAX
MIN
MOD
NOW
NULLIF
PI
POSITION
POW
POWER
RADIANS
RANDOM
REGEXP_REPLACE
REPLACE
RIGHT
ROUND
RPAD
RTRIM
SIGN
SIN
SQRT
STDDEV
STDDEV_POP
STDDEV_SAMP
STRPOS
SUBSTR
SUBSTRING
SUM
TAN
TIMESTAMPADD
TIMESTAMPDIFF
TO_CHAR
TO_DATE
TO_NUMBER
TO_TIMESTAMP
TRIM
TRUNC
TRUNCATE
UCASE
UPPER
VAR_POP
VAR_SAMP
VARIANCE