# The C++ SqlOptimizerParameters Class

> The SqlOptimizerParameters class provides options for tuning performance of the SQL engine.

> ### For an overview see page C++ Classes

> The SqlOptimizerParameters properties are defined as follows in file `/include/sql/sqlcpp.h`:

>         SqlOptimizerParameters::SqlOptimizerParameters()
>         {
>             batchInsertBufferSize = 1024;
>             workMemLimit = (size_t)-1;
>             nShuffleFiles = 128;
>             preloadUDF = false;
>         }

> The SqlOptimizerParameters described in the table below are used to tune the SQL engine behavior:

> batchInsertBufferSize | The size of the buffer for bulk (batch) insert operations
> workMemLimit | The work memory limit used by sort operations
> nShuffleFiles | The number of files used for shuffle join
> preloadUDF | If true, causes the SQL engine to preload all UDFs from dynamic load libraries