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1.8.7.6 Using DTrace for tracing PostgreSQL

Yes, using DTrace is possible. See section 13.4 Dynamic Tracing for further information. You can also find more information in this article: http://blogs.sun.com/robertlor/entry/user_level_dtrace_probes_in.

If you see the linking of the postgres executable abort with an error message like:

Undefined                       first referenced
 symbol                             in file
AbortTransaction                    utils/probes.o
CommitTransaction                   utils/probes.o
ld: fatal: Symbol referencing errors. No output written to 
  postgres
collect2: ld returned 1 exit status
gmake: *** [postgres] Error 1

your DTrace installation is too old to handle probes in static functions. You need Solaris 10u4 or newer.