Drivers that support connecting to a proxy server through an HTTP connection employ a library file (xxcurlnn.dll) that is copied to the product directory during installation. The library file is required if you plan to use the HTTP proxy functionality with your driver. However, if your application does not use HTTP proxy functionality, or if HTTP proxy functionality is not supported with your driver, distributing the file is optional. The installer library file is branded with other driver files when branding the product.

The following table contains driver functionality that requires libraries for HTTP connections.

Table 1. Functionality that requires the xxcurlnn.dll file
Driver Functionality
Amazon Redshift Wire Protocol HTTP Proxy
Apache Hive Wire Protocol
  • Apache Knox
  • HTTP Transport (HTTP mode)
Apache Spark SQL Wire Protocol
  • Azure Databricks Spark clusters
  • HTTP Transport (HTTP mode)
Google Analytics 4 Custom tables
MySQL Wire Protocol HTTP Proxy
Oracle Wire Protocol
  • HTTP Proxy
  • Oracle Connection Manager
PostgreSQL Wire Protocol
  • HTTP Proxy
  • Microsoft Entra ID Authentication
SQL Server Wire Protocol
  • Always Encrypted
  • HTTP Proxy
  • Microsoft Entra ID Authentication