Data items are either keys or results.
A key data item uniquely identifies the rows returned in a view. For example, in a view that defines per-process data, the Process ID data item identifies each process.
A result data item identifies the information to be returned concerning each key value.
By using a mix of keys and results to define recording session views, you control the data that Historical Server returns.
You can combine key data items within a view to narrow the scope of the returned data. With the inclusion of each successive key, envision adding the word “per” to a view definition. For example, page I/Os “per” database table “per” process. (Only certain key combinations are valid for each data item. See Table B-2.)
To return server-wide data, define a view with no keys. In a view with no keys, the result always contains exactly one row. (Only certain data items are valid at the server level. See Table B-2.)
Table B-1 provides examples of views using different key combinations.
View definition |
Results |
|---|---|
Page I/O |
Since there are no keys in the view, the result is page I/O for the whole server. For example: Page I/O -------- 145 |
Process ID (key), Login Name, Page I/O |
The result is page I/O per process. For example: Process ID Login Name Page I/O -------------------------------------- 1 sa 45 5 joe 100 |
Process ID (key), Database ID (key), Object ID (key), Database Name, Object Name, Page I/O |
The result is page I/O per database table per process. For example: Process Database Object Databse Object Page ID ID ID Name Name I/O --------------------------------------------- 1 5 208003772 pubs2 authors 10 1 5 336004228 pubs2 titles 35 5 5 208003772 pubs2 authors 100 |
