# AsyncDistributedSqlEngine: constructor

This article is deprecated.

> Create an instance of AsyncDistributedSqlEngine.

> ### For an overview see page AsyncDistributedSqlEngine

> This is an variant of DistributedSqlEngine that facilitates execution of several queries at the same time. It allows starting a list of queries simultaneously and waiting for all results to arrive at client processes using shards of the database.

> ### Prototype

>         AsyncDistributedSqlEngine(size_t nWorkers = 1,
>                         size_t txBufSize = 64 * 1024);

> ### Arguments

> nWorkers | The number of worker processes
> txBufSize | Specifies the size of transmit buffer used to serialize requests to be sent to the server (default is 64k)

> ### Description

> This constructor creates an instance of AsyncDistributedSqlEngine.

> ### Example

> Typically a C++ application will instantiate an AsyncDistributedSqlEngine object in the main program as illustrated below:

>         const size_t nWorkers = 4;

>         int main(int argc, char** argv)
>         {
>             try {

>                 McoSql::AsyncDistributedSqlEngine engine(nWorkers);
>                 ...
>             }
>         }