txn performance penalty

[David Relson]

On Thu, 11 Nov 2004 12:26:16 +0100
Matthias Andree wrote:

> Matthias Andree <matthias.andree at gmx.de> writes:
> 
> > DB_CONFIG options at your service. Clock "set_flags
> > DB_TXN_NOT_DURABLE" and see if it helps. It is really dangerous, but
> > there are more "operate asynchronously", "write fewer data" options.
> 
> The updated doc/README.db file as of 0.93.1 contains documentation on
> the "interesting" options.

For personal curiosity, I ran bogoutil (versions 0.92.8 and 0.93.1) to
build new database.  From a 1,471,863 line (38M) text wordlist it built
a 54M database. "time" reports:

for bogoutil 0.92.8 (with Berkeley DB 4.2.52)

   11.03user 0.64system 0:12.74elapsed 91%CPU 
        (0avgtext+0avgdata 0maxresident)k
   0inputs+0outputs (2major+1564minor)pagefaults 0swaps

for bogoutil 0.93.1 (with Berkeley DB 4.2.52)

   22.75user 2.70system 0:37.05elapsed 68%CPU 
        (0avgtext+0avgdata 0maxresident)k
   0inputs+0outputs (115major+2135minor)pagefaults 0swaps

Total disk usage for 0.92.8 was 54M and for 0.93.1 it was 332M (log
files).

Conclusion: writing log files takes time -- not a surprise.