# 6.7.39 SHOW MPI ROOT

Part of: [6 Language](6-language.md) › [6.7 Data Introspection Language (DIL)](6-7-data-introspection-language-dil.md)

### Syntax

**SHOW** **MPI** **ROOT**\
[_post_processing_option_]\
[_output_redirecting_option_]

### Description

Show (i.e. get) the MPI root process rank (for gathering processed (HDF5) data by other MPI processes) that may have been set through the operation [SET MPI ROOT](6-8-13-set-mpi-root.md). If using an HDFql non MPI-based distribution, an error is raised.

### Parameter(s)

_post_processing_option_ – optional option that transforms the result set according to the programmer’s needs, such as ordering or truncating (please refer to the section [PROCESSING](6-2-processing.md) for additional information).

_output_redirecting_option_ – optional option that specifies the cursor in use, an HDF5 object (i.e. dataset or attribute), a (text, binary, or Excel) file, or memory (i.e. user-defined variable) to write the result set into (please refer to the subsection [INTO](6-3-2-into.md) for additional information). If not specified, the cursor in use is populated with the result set instead (please refer to the chapter [CURSOR](4-cursor.md) for additional information).

### Return

The MPI root process rank (for gathering processed (HDF5) data by other MPI processes) as an [HDFQL_INT](5-1-constants.md#hdfql_int).

### Example(s)

```hdfql
# set the MPI root process rank (to use when gathering processed (HDF5) data by other MPI processes) to 3
SET MPI ROOT 3

# show (i.e. get) rank of the MPI process specified as the root (should return 3) 
SHOW MPI ROOT

# set the MPI root process rank (to use when gathering processed (HDF5) data by other MPI processes) to the default value (i.e. 0)
SET MPI ROOT DEFAULT

# show (i.e. get) rank of the MPI process specified as the root (should return 0) 
SHOW MPI ROOT 
```