Default: 1048576


The READSIZE parameter lets you specify (in bytes) the size of the read buffer, if you choose not to use the default.

Syntax and Description


In the conventional path method, the bind array is limited by the size of the read buffer. Therefore, the advantage of a larger read buffer is that more data can be read before a commit operation is required.

For example, setting READSIZE to 1000000 enables SQL*Loader to perform reads from the data file in chunks of 1,000,000 bytes before a commit is required.


If the READSIZE value specified is smaller than the BINDSIZE value, then the READSIZE value will be increased.



  • The READSIZE parameter is used only when reading data from data files. When reading records from a control file, a value of 64 kilobytes (KB) is always used as the READSIZE.

  • The READSIZE parameter has no effect on LOBs. The size of the LOB read buffer is fixed at 64 kilobytes (KB).

  • The maximum size allowed is platform dependent.


The following example sets the size of the read buffer to 500,000 bytes which means that commit operations will be required more often than if the default or a value larger than the default were used.