--- layout: docu redirect_from: - /docs/api/c/config - /docs/api/c/config/ - /docs/clients/c/config title: Configuration --- Configuration options can be provided to change different settings of the database system. Note that many of these settings can be changed later on using [`PRAGMA` statements](../../configuration/pragmas) as well. The configuration object should be created, filled with values and passed to `duckdb_open_ext`. ## Example ```c duckdb_database db; duckdb_config config; // create the configuration object if (duckdb_create_config(&config) == DuckDBError) { // handle error } // set some configuration options duckdb_set_config(config, "access_mode", "READ_WRITE"); // or READ_ONLY duckdb_set_config(config, "threads", "8"); duckdb_set_config(config, "max_memory", "8GB"); duckdb_set_config(config, "default_order", "DESC"); // open the database using the configuration if (duckdb_open_ext(NULL, &db, config, NULL) == DuckDBError) { // handle error } // cleanup the configuration object duckdb_destroy_config(&config); // run queries... // cleanup duckdb_close(&db); ``` ## API Reference Overview

duckdb_state duckdb_create_config(duckdb_config *out_config);
size_t duckdb_config_count();
duckdb_state duckdb_get_config_flag(size_t index, const char **out_name, const char **out_description);
duckdb_state duckdb_set_config(duckdb_config config, const char *name, const char *option);
void duckdb_destroy_config(duckdb_config *config);

#### `duckdb_create_config` Initializes an empty configuration object that can be used to provide start-up options for the DuckDB instance through `duckdb_open_ext`. The duckdb_config must be destroyed using 'duckdb_destroy_config' This will always succeed unless there is a malloc failure. Note that `duckdb_destroy_config` should always be called on the resulting config, even if the function returns `DuckDBError`. ##### Syntax

duckdb_state duckdb_create_config(
  duckdb_config *out_config
);

##### Parameters * `out_config`: The result configuration object. ##### Return Value `DuckDBSuccess` on success or `DuckDBError` on failure.
#### `duckdb_config_count` This returns the total amount of configuration options available for usage with `duckdb_get_config_flag`. This should not be called in a loop as it internally loops over all the options. ##### Return Value The amount of config options available. ##### Syntax

size_t duckdb_config_count(
  
);

#### `duckdb_get_config_flag` Obtains a human-readable name and description of a specific configuration option. This can be used to e.g. display configuration options. This will succeed unless `index` is out of range (i.e., `>= duckdb_config_count`). The result name or description MUST NOT be freed. ##### Syntax

duckdb_state duckdb_get_config_flag(
  size_t index,
  const char **out_name,
  const char **out_description
);

##### Parameters * `index`: The index of the configuration option (between 0 and `duckdb_config_count`) * `out_name`: A name of the configuration flag. * `out_description`: A description of the configuration flag. ##### Return Value `DuckDBSuccess` on success or `DuckDBError` on failure.
#### `duckdb_set_config` Sets the specified option for the specified configuration. The configuration option is indicated by name. To obtain a list of config options, see `duckdb_get_config_flag`. In the source code, configuration options are defined in `config.cpp`. This can fail if either the name is invalid, or if the value provided for the option is invalid. ##### Syntax

duckdb_state duckdb_set_config(
  duckdb_config config,
  const char *name,
  const char *option
);

##### Parameters * `config`: The configuration object to set the option on. * `name`: The name of the configuration flag to set. * `option`: The value to set the configuration flag to. ##### Return Value `DuckDBSuccess` on success or `DuckDBError` on failure.
#### `duckdb_destroy_config` Destroys the specified configuration object and de-allocates all memory allocated for the object. ##### Syntax

void duckdb_destroy_config(
  duckdb_config *config
);

##### Parameters * `config`: The configuration object to destroy.