TKPROF’s Argument PDBTRACE
If you run TKPROF without arguments, you get a complete list of its arguments with a short description for each of them (here the output generated by version 18.1.0):
$ tkprof Usage: tkprof tracefile outputfile [explain= ] [table= ] [print= ] [insert= ] [sys= ] [sort= ] table=schema.tablename Use 'schema.tablename' with 'explain=' option. explain=user/password Connect to ORACLE and issue EXPLAIN PLAN. print=integer List only the first 'integer' SQL statements. pdbtrace=user/password Connect to ORACLE to retrieve SQL trace records. aggregate=yes|no insert=filename List SQL statements and data inside INSERT statements. sys=no TKPROF does not list SQL statements run as user SYS. record=filename Record non-recursive statements found in the trace file. waits=yes|no Record summary for any wait events found in the trace file. sort=option Set of zero or more of the following sort options: prscnt number of times parse was called prscpu cpu time parsing prsela elapsed time parsing prsdsk number of disk reads during parse prsqry number of buffers for consistent read during parse prscu number of buffers for current read during parse prsmis number of misses in library cache during parse execnt number of execute was called execpu cpu time spent executing exeela elapsed time executing exedsk number of disk reads during execute exeqry number of buffers for consistent read during execute execu number of buffers for current read during execute exerow number of rows processed during execute exemis number of library cache misses during execute fchcnt number of times fetch was called fchcpu cpu time spent fetching fchela elapsed time fetching fchdsk number of disk reads during fetch fchqry number of buffers for consistent read during fetch fchcu number of buffers for current read during fetch fchrow number of rows fetched userid userid of user that parsed the cursor
If you carefully check the output, you can notice an argument that does exist only from version 12.2 onward: “pdbtrace”. If I correctly remember, since the introduction of TKPROF in Oracle7, only another time Oracle added a new argument. It was “waits” in Oracle9. Interestingly, the documentation provides no information about it.
So, the question is: what does the new argument do?
Since its name contains “pdb”, one might think that it is related to Multitenant. But, after a number of tests, it does not seem to be related to it. Simply put, “pdbtrace” can be used to process a trace file without requiring direct access to the OS where the trace file is stored. Instead, when “pdbtrace” is specified, the trace file is read through one of the dynamic performance views introduced in version 12.2 to access them (e.g. V$DIAG_TRACE_FILE and V$DIAG_TRACE_FILE_CONTENTS; have a look to this post for some basic information about them).
For example, the following command instructs TKPROF to connect a database instance with the specified user and password, to read the input file DBM1810S_ora_18264.trc, and produce the output file DBM1810S_ora_18264.txt locally.
$ tkprof DBM1810S_ora_18264.trc DBM1810S_ora_18264.txt pdbtrace=chris/secret@pdb1
All in all, except for the name, a good addition to TKPROF.
Be careful that when the “pdbtrace” argument is specified, the input trace file can’t specify the directory where the trace file is located. If a directory name or a non-existent trace file is specified, no interactive error message is shown. Instead, an empty output file is generated. Similarly, if an invalid user, password, or connect string is specified, an empty output file is generated without any interactive error message. Instead, an error like the following will be found in the output file just before the header:
error connecting to database using: scott/lion ORA-01017: invalid username/password; logon denied