## • file_ios 

The total number of file I/O events for the host. 

## • file_io_latency 

The total wait time of timed file I/O events for the host. 

## • current_connections 

The current number of connections for the host. 

## • total_connections 

The total number of connections for the host. 

## • unique_users 

The number of distinct users for the host. 

## • current_memory 

The current amount of allocated memory for the host. 

## • total_memory_allocated 

The total amount of allocated memory for the host. 

## 28.4.3.2 The host_summary_by_file_io and x$host_summary_by_file_io Views 

These views summarize file I/O, grouped by host. By default, rows are sorted by descending total file I/O latency. 

The host_summary_by_file_io  and x$host_summary_by_file_io  views have these columns: 

## • host 

The host from which the client connected. Rows for which the HOST  column in the underlying Performance Schema table is NULL  are assumed to be for background threads and are reported with a host name of background . 

## • ios 

The total number of file I/O events for the host. 

## • io_latency 

The total wait time of timed file I/O events for the host. 

## 28.4.3.3 The host_summary_by_file_io_type and x$host_summary_by_file_io_type Views 

These views summarize file I/O, grouped by host and event type. By default, rows are sorted by host and descending total I/O latency. 

The host_summary_by_file_io_type  and x$host_summary_by_file_io_type  views have these columns: 

• host 

