[Node-DuckDB API](./node-duckdb.md) > [DuckDB](./node-duckdb.duckdb.md) ## DuckDB class The DuckDB class represents a DuckDB database instance. Signature: ```typescript export declare class DuckDB ``` ## Constructors | Constructor | Modifiers | Description | | -------------------------------------------------------------- | --------- | --------------------------------------- | | [(constructor)(config)](./node-duckdb.duckdb._constructor_.md) | | Represents a native instance of DuckDB. | ## Properties | Property | Modifiers | Type | Description | | ---------------------------------------------------------------------- | --------- | --------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------ | | [accessMode](./node-duckdb.duckdb.accessmode.md) | | [AccessMode](./node-duckdb.accessmode.md) | Returns the [access mode](./node-duckdb.accessmode.md) used by the database. | | [checkPointWALSize](./node-duckdb.duckdb.checkpointwalsize.md) | | number | Returns the checkpoint write ahead log size used by the database. | | [collation](./node-duckdb.duckdb.collation.md) | | string | Returns the collation used by the database. | | [defaultNullOrder](./node-duckdb.duckdb.defaultnullorder.md) | | [OrderByNullType](./node-duckdb.orderbynulltype.md) | Returns the default [sort order for null values](./node-duckdb.orderbynulltype.md). | | [defaultOrderType](./node-duckdb.duckdb.defaultordertype.md) | | [OrderType](./node-duckdb.ordertype.md) | Returns the default [sort order](./node-duckdb.ordertype.md). | | [isClosed](./node-duckdb.duckdb.isclosed.md) | | boolean | Returns true if the underlying database has been closed, false otherwise. | | [maximumMemory](./node-duckdb.duckdb.maximummemory.md) | | number | Returns the maximum memory limit for the database. | | [temporaryDirectory](./node-duckdb.duckdb.temporarydirectory.md) | | string | Returns the temporary directory location for the database. | | [useTemporaryDirectory](./node-duckdb.duckdb.usetemporarydirectory.md) | | boolean | Returns true if the database uses a temporary directory for storing data that does not fit into memory, false otherwise. | ## Methods | Method | Modifiers | Description | | ------------------------------------------------------------------ | ------------------- | ---------------------------------------------------------------------------------------- | | [close()](./node-duckdb.duckdb.close.md) | | Closes the underlying duckdb database, frees associated memory and renders it unusuable. | | [getBindingsVersion()](./node-duckdb.duckdb.getbindingsversion.md) | static | Returns the current version of the node-duckdb package (from package.json) |