Connector node settings
This reference covers the JDBC Parameters and Additional Settings sections available in DB connector nodes, under Show advanced settings. Dedicated connector nodes (for example, MySQL Connector) expose only a subset of these options; the generic DB Connector exposes all of them.
JDBC parameters
The JDBC Parameters section lets you define custom driver connection parameters to pass to the database. Each parameter takes a name and a value. The value type determines how the value is supplied:
| Value type | Description |
|---|---|
| Constant | A fixed string value |
| Variable | A KNIME flow variable |
| Credential user | The username from a credential flow variable |
| Credential password | The password from a credential flow variable |
| KNIME URL | A knime:// URL |
| Path flow variable | A path from a standard file system flow variable. Connected file systems are not supported. |
Additional settings
The Additional Settings section controls how KNIME communicates with the database. Most settings have sensible defaults; change them only when your database requires it.
Connection
| Setting | Description |
|---|---|
| Automatically close idle connection timeout | Time interval in seconds before an idle connection closes automatically. A value of 0 disables automatic closing. |
| Automatically reconnect to database | Reconnects if the connection becomes invalid. Connection-dependent objects are lost after reconnection. |
| Reconnect to database timeout | Time interval in seconds to wait before cancelling a reconnection attempt. A value of 0 uses the standard connection timeout. |
| Restore database connection | Restores the connection when an executed connector node is loaded. |
| Validation query | SQL query used to test whether the connection is ready. If empty, KNIME calls Connection.isValid(). |
Dialect capabilities
| Setting | Description |
|---|---|
| CASE expressions | Whether CASE expressions are allowed in generated statements. |
| CREATE TABLE CONSTRAINT name | Whether CONSTRAINT names can be defined in CREATE TABLE statements. |
| DROP TABLE statement | Whether DROP TABLE statements are supported. |
| Derived table reference | Whether table references can be derived tables (subqueries). |
| Insert into table from query | Whether INSERT INTO … SELECT is supported. |
Dialect syntax
| Setting | Description |
|---|---|
| CREATE "temporary" TABLE syntax | Keyword(s) for creating temporary tables. |
| CREATE TABLE "if not exists" syntax | Syntax for the IF NOT EXISTS condition. Empty means no such condition is generated. |
| Delimit only identifier with spaces | When selected, only identifiers that contain spaces are delimited. |
| Identifier delimiter (closing) | Closing delimiter for table and column names. |
| Identifier delimiter (opening) | Opening delimiter for table and column names. |
| Identifier non-word character replacement | Replacement string for non-word characters in identifiers. Empty means non-word characters are removed. |
| Replace non-word characters in identifiers | Whether to replace non-word characters (anything other than a–z, A–Z, 0–9, _) in identifiers. |
| Table reference keyword | Keyword before correlation names in table references. |
JDBC logger
| Setting | Description |
|---|---|
| Enable | Writes all JDBC operations to the KNIME log. Use for troubleshooting connection errors. |
JDBC statement cancellation
| Setting | Description |
|---|---|
| Enable | Attempts to cancel the JDBC statement when node execution is cancelled. |
| Node cancellation polling interval | Milliseconds between checks for node cancellation. Valid range: 100–5000. |
Metadata
| Setting | Description |
|---|---|
| Flatten sub-queries where possible | Collapses nested subqueries into a single query. Disabled by default. Enable only when the database has performance problems with subqueries or does not support them. Not all queries can be flattened. |
| List of table types to show in metadata browser | Comma-separated list of table types to display. Some databases (for example, SAP HANA) support additional types such as CALC VIEW and HIERARCHY VIEW. |
| Retrieve in configure | Retrieves metadata during node configuration. |
| Retrieve in configure timeout | Seconds to wait before cancelling a metadata retrieval in configure. Valid range: 1 or greater. |
Other
| Setting | Description |
|---|---|
| Fail if WHERE clause contains any missing value | Fails the node if any value in a WHERE clause (for example, in update, delete, or merge operations) is missing. |
| Fetch result of DB SQL Executor as debug log | Fetches the result of a DB SQL Executor node and writes it to the KNIME log for debugging. |
| Fetch size | Hint to the JDBC driver about how many rows to fetch at a time. Valid range: 0 or greater. |
| Support multiple databases | Enables statements that reference more than one database. |