IBM Db2

IBM Db2 is a data source that contains relational data.

You can configure IBM Db2 using one of the following methods:

Create new connection – If you select the Create new connection tab, refer to the Create new connection - configuration details table to provide configuration details.
Import from catalog – You can import connection details from an existing catalog in the data platform. If you select the Import from catalog tab, refer to the Import from catalog - configuration details table to provide configuration details.
Import from project – You can import connection details from an existing project in the data platform. If you select Import from project, refer to the Import from project - configuration details table to provide configuration details.

Create new connection - configuration details

Crete new connection - configuration details
Field	Description
Display name	Enter the data source name to be displayed on the screen.
Database name	Enter the name of your database.
Hostname	Enter the hostname.
Port	Enter the port number.
Authentication type	Choose and enter the Authentication type details. Username and password: Enter the username and password. API key: Enter the API key.
Port is SSL enabled	Use the toggle switch to enable or disable SSL connection. If enabled, i. The Upload SSL certificate (.pem, .crt, .cert or .cer) link is enabled. ii. Click the Upload SSL certificate (.pem, .crt, .cert or .cer) link. iii. Browse the SSL certificate and upload.
Connection Status	Click the Test connection link to test the data source connection. If the data source connection is successful, a success message appears.
Associate catalog	Select the checkbox to associate a catalog to the data source. This catalog is automatically associated with your data source and serves as your query interface with the data stored within.
Catalog name	Enter the name of the catalog.
Create	Click Create to create the data source.

Import from catalog - configuration details

Import from catalog - configuration details
Field	Description
Select catalog	Use the dropdown to select a catalog.
Select data source	Use the dropdown to select a data source from the selected catalog.
Connection status	Click the Test connection link to test the database connection. If the database connection is successful, a success message appears.
Display name	Enter the database name to be displayed on the screen.
Associate catalog	Select the checkbox to associate a catalog to the data source. This catalog is automatically associated with your data source and serves as your query interface with the data stored within.
Catalog name	Enter the name of the catalog.
Create	Click Create to create the database.

Import from project - configuration details

Import from project - configuration details
Field	Description
Select project	Use the dropdown to select a project.
Select data source	Use the dropdown to select a data source from the selected project
Connection status	Click the Test connection link to test the database connection. If the database connection is successful, a success message appears.
Display name	Enter the database name to be displayed on the screen.
Associate catalog	Select the checkbox to associate a catalog to the data source. This catalog is automatically associated with your data source and serves as your query interface with the data stored within.
Catalog name	Enter the name of the catalog.
Create	Click Create to create the database.

Select IBM Db2 from the data source section to add IBM Watson Query. You can now query the nicknames that are created in IBM Db2 and the virtualized tables from Watson Query instances.

Features

You can perform the following operations for BLOB and CLOB data types for IBM Db2 data source:
- INSERT
- CREATE
- CTAS
- ALTER
- DROP

To insert CLOB data type, provide the value directly or cast it explicitly to CLOB data type.

INSERT INTO <table_name> VALUES ('<clob value>', '<other values>');
INSERT INTO <table_name> VALUES (CAST('<clob text>' AS CLOB));

To insert BLOB data, use the cast function with BLOB data type. The corresponding hexadecimal value is inserted into the IBM Db2 data source:
```
INSERT INTO <table_name> VALUES (CAST('<blob text>' AS BLOB));
```

Limitations for SQL statements

ALTER TABLE DROP COLUMN operation is not supported for column-organized tables.
DROP TABLE statement is supported only when enabled in the catalog.
CREATE VIEW can be used for a table only if that table is in the same catalog.
DROP SCHEMA can do RESTRICT by default.
For data source-based catalogs the CREATE SCHEMA, CREATE TABLE, DROP SCHEMA, DROP TABLE, DELETE, DROP VIEW, ALTER TABLE, and ALTER SCHEMA statements are not available in the Data Manager UI.
In the CREATE VIEW statement, column names must be enclosed in double quotes, and their case must match exactly as they are stored in the database, including uppercase, lowercase, or mixed case.
The ALTER VIEW RENAME operation is not supported.

Limitations for data types

BLOB and CLOB data types support SELECT statement but do not support operations such as equal, like, and in.
BINARY data type supports only SELECT statement.
When the fields of data type REAL have 6 digits or more in the decimal part with the digits being predominately zero, the values when queried are rounded off. It is observed that the rounding off occurs differently based on the precision of the values. For example, a decimal number 1.654 when rounded to 3-digits after the decimal point are the same. Another example is 10.890009 and 10.89000. It is noticed that 10.89000 is rounded to 10.89, whereas 10.89009 is not rounded off. This is an inherent issue because of the representational limitations of binary floating point formats. This might have a significant impact when querying involves sorting.