Many questions I see on the internet could be resolved by the simple expedient of looking at the information that’s in front of you; and many of the questions that clutter up forums and newsgroup would simply cease to appear if more people adopted this approach. Here’s an example of what I mean:
According to Metalink note 34559.1 the p1 value is the absolute file number. According to dba_data_files all my file numbers are one, two or three digits, but when I “select distinct p1 from v$session_wait” I am seeing a file number (p1) of 1413697536. Why is this appearing ?
No doubt someone reading this post will look at that number and immediately recognise it as coming from an SQL*Net message wait on a tcp connection (1413697536 = 0x54435000 -> 0x54 0x43 0x50 -> T C P) and may wonder why the Metalink note didn’t explain that p1 was the absolute file number only when the wait was related to some sort of file I/O. This was the thought that crossed my mind, so I logged on to MOS to see what the note said (because sometimes I fill in the feedback form to correct the errors or ask for a note to be withdrawn) and this is what I found:
Title of note: “db file sequential read” Reference Note
First line of note: This is a reference note for the wait event “db file sequential read” which …
I find that I can’t conjure up any circumstances where a person could know enough to query v$session_wait and dba_data_files, and yet not notice the significance of the title and first line of the metalink note.
Footnote: According to a story I heard recently, there is at least one site where the management has blocked access to any internet sites that cause too much traffic on the company network. Unfortunately the IT department seemed to spend a lot of time reading the Oracle online documentation. So whenever I see the expression RTFM I now interpret it as “read the firewalled manuals”.