Adding a Teradata Connection

Technical Documentation : Connectors : Adding a Teradata Connection

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Prerequisites

In order to establish a connection with Teradata, a user with sufficient permissions is required.
Zeenea traffic flows towards the database must be opened.

Important: The Teradata driver is not delivered with the connector with scanner version 34 and later. Download the Teradata driver related to your Teradata instance and move it into the /lib-ext folder of your scanner. You will find the driver into sources provided by the editor on their website: https://downloads.teradata.com/download/connectivity/jdbc-driver.

Note: You can find a link to the configuration template in Zeenea Connector Downloads.

Supported Versions

The Teradata connector is compatible with Teradata version 16. Data profiling feature is available since scanner version 33.

Installing the Plugin

From version 54 of the scanner, the Teradata connector is presented as a plugin.

It requires a scanner version 66 and can be downloaded here: https://plugins.zeenea.app/jdbc-connector-plugin/jdbc-connector-plugin-66.zip.

For more information on how to install a plugin, please refer to the following article: Installing and Configuring Connectors as a Plugin.

Declaring the Connection

Creating and configuring connectors is done through a dedicated configuration file located in the /connections folder of the relevant scanner.

Read more: Managing Connections

In order to establish a connection with Teradata, specifying the following parameters in the dedicated file is required:

Parameter	Expected value
name	The name that will be displayed to catalog users for this connection.
code	The unique identifier of the connection on the Zeenea platform. Once registered on the platform, this code must not be modified or the connection will be considered as new and the old one removed from the scanner.
connector_id	The type of connector to be used for the connection. Here, the value must be Teradata and this value must not be modified.
connection.url	Database address. It is possible to add specific parameters through URL. Example : jdbc:teradata://localhost/CHARSET=UTF8,LOG=...
connection.username	Username
connection.password	User password
inventory.primary_keys	Retrieve Primary Indexes as Primary key if the parameter set to primary_index. Default value is primary_key.
filter	To filter datasets during the inventory. See Rich Filters.
roles	To filter the "Roles" metadata. See Rich Filters.
extract.dbc.use_qvci	Define which DBC view will be used to extract columns metadata. - use_qvci = "false": DBC.ColumnsV (default value, table's columns metadata only) - use_qvci = "true": DBC.ColumnsQV (table's and view's columns metadata). Before setting use_qvci flag to true, you must activate QVCI (Queryable Column Information on Views) feature on the Teradata platform.
cache.enabled	Enable the cache functionality. When the cache is activated, the schema update performs four queries in total instead of four per imported table. The result is greater efficiency.
cache.folder	The size of the cache file produced depends on the number of tables in the database (and not on the number of tables imported into Zeenea). If the folder is not specified, the cache is stored in memory.
cache.ttl	Cache validity period (default 12h). As long as the cache is valid, requests that fill it are not executed.

Note: In order to read data with the desired encoding CHARSET, you have to add "CHARSET=" parameter to the JDBC URL.

Here is an exhaustive list of all encoding types : https://teradata-docs.s3.amazonaws.com/doc/connectivity/jdbc/reference/current/jdbcugchapter2.html#URL_CHARSET

Note: A template of the configuration file is available in this repository.

User Permissions

In order to collect metadata, the running user must have read-only access to databases that need to be cataloged.

If the data profiling feature was enabled, the user must have read access on impacted tables. Otherwise, this permission is not necessary.

Rich Filters

Since version 47 of the scanner, the Teradata connector benefits from the feature of rich filters in the configuration of the connector. The keys that can be used to filter the elements are the standard ones for JDBC (schema, table) but also on the type of the table.

This functionality also applies to the Roles metadata of the datasets from the roles parameters to be completed with the role key. Example: roles = "role in ('role1', 'role2')".

Read more: Filters

Criteria	Description
schema	Schema name
table	Table or view name
type	Objects type See all table types here: https://docs.teradata.com/r/Teradata-VantageTM-Data-Dictionary/March-2019/View-Column-Values/TableKind-Column
roles	Role datasets metadata

Data Extraction

To extract the information, the connector will perform queries, depending on the scanner version, on the dbc.tables, dbc.columns and dbc.databases tables for versions less than or equal to 42 or on the DBC.TablesV, DBC.ColumnsV (or DBC.ColumnsQV if the QVCI functionality is active) and DBC.DatabasesV tables for versions greater than or equal to 44.

Collected Metadata

Inventory

The inventory collects all data accessible by the user.

Dataset

Here, a dataset can be a table or a view.

Name
Source Description
Technical Data:
- Schema
- Table
- Last Alter Time
- Type
- Roles

Field

Dataset field.

Name
Source Description
Type
Can be null: Depending on field settings
Multivalued: Not supported. Default value false.
Primary Key: Depending on field settings
Technical Data:
- Technical Name: field technical name
- Native type: field native type
- Field Size

Data Profiling

Important: The Data Profiling feature, which can be enabled on this connection, allows your Explorers to get a better grasp on the type of data stored in each fields. This feature, which can be activated in the Scanner, is by default set to run on a weekly basis, every Saturday. However, depending on the number of fields you've activated this feature for, the calculation can quickly become costly. Please make sure the estimated impact of this feature is acceptable and that the default frequency appropriate, before enabling it.

The statical profiles feature, also named "data profiling", is available for this connector. The impact of this feature must be evaluated before its activation on any of your connections. You can find more information about the resulting statistics in the following documentation: Data Profiling.

Read access on targeted tables is mandatory to activate the feature. For Teradata technologies, the connector executes the following request to get a data sample:

SELECT COUNT(*) AS result FROM tableName

The request above defines the number of rows in the table tableName.

SELECT
field1, field2
FROM tableName
SAMPLE (linesPercentage)

The request above collects a data sample for each field where the feature is activated through the studio (field1, field2). The limit is 10.000 lines (linesPercentage parameter) deduced from a calculation with the number of rows set in the previous request.

These requests will be executed, whether manually, in case of user action directly on the admin portal, or periodically according to the parameter collect-fingerprint from the application.conf file, as described in Zeenea Scanner Setup.

Object Identification Keys

A key is associated with each item of the catalog. When the object comes from an external system, the key is built and provided by the connector.

Object	Identification Key	Description
Dataset	code/schema/dataset name	- code: Unique identifier of the connection noted in the configuration file - schema: Dataset schema - dataset name
Field	code/schema/dataset name/field name	- code: Unique identifier of the connection noted in the configuration file - schema: Dataset schema - dataset name - field name