The diskstat table provides information about
        writes to Disk Data tablespaces during the past 1 second.
      
        The diskstat table contains the following
        columns:
- node_id- Node ID of this node 
- block_instance- ID of reporting instance of - PGMAN
- pages_made_dirty- Number of pages made dirty during the past second 
- reads_issued- Reads issued during the past second 
- reads_completed- Reads completed during the past second 
- writes_issued- Writes issued during the past second 
- writes_completed- Writes completed during the past second 
- log_writes_issued- Number of times a page write has required a log write during the past second 
- log_writes_completed- Number of log writes completed during the last second 
- get_page_calls_issued- Number of - get_page()calls issued during the past second
- get_page_reqs_issued- Number of times that a - get_page()call has resulted in a wait for I/O or completion of I/O already begun during the past second
- get_page_reqs_completed- Number of - get_page()calls waiting for I/O or I/O completion that have completed during the past second
Notes
        Each row in this table corresponds to an instance of
        PGMAN; there is one such
        instance per LDM thread plus an additional instance for each
        data node.