Fragment metrics

These metrics take the dbspace of an individual table fragment as the metric scope.

Metric Name	Description
Lock Requests	Total requests to lock fragment
Lock Waits	Number of times that threads have waited to obtain a lock for the fragment
Deadlocks	Number of times that a deadlock involved the fragment
Deadlock Timeouts	Number of times that a deadlock timeout involved the fragment
Reads	Number of read calls that involve the fragment
Writes	Number of write calls that involve the fragment
Rewrites	Number of rewrite calls that involve the fragment
Deletes	Number of delete calls that involve the fragment
Calls	Total calls that involve the fragment
Buffer Reads	Number of buffer reads that involve fragment data
Buffer Writes	Number of buffer writes that involve fragment data
Sequential Scans	Number of sequential scans of the fragment
Percent Free Space	Percent of the fragment that is free
Pages Allocated	Number of pages allocated to the fragment
Pages Used	Number of pages allocated to the fragment that have been written to
Data Pages	Number of pages allocated to the fragment that are used as data pages