[Zope-dev] Searching/Indexing/ZODB/SQL/BerkleyDB

[Barry A. Warsaw]

>>>>> "CW" == Chris Withers <chrisw@nipltd.com> writes:

    >> How much slower was is? Did you measure ratios (between the two
    >> storages) of time per indexing operation, or ratios of disk
    >> blocks transferred per indexing operation?

    CW> In my tests, Barry agreed with me that Berkley was turning out
    CW> between one and two _orders or magnitude_ slower than
    CW> FileStorage :-(

Actually, let me clarify this!  I just pointed out that your numbers
showed you were seeing a two orders of magnitude difference.

However, in my own testing, on my own data, I've been able to reduce
the performance difference to about a factor of 4.5 -- much better
than the factor of 100 your numbers showed for you data!  I would not
make the blanket assertion that Berkeley storage is 100 times slower
than FileStorage.

Let me just reiterate: it's vitally important to tune your Berkeley
storage for your system and application, especially with regards to
cachesize.  E.g. Getting the cachesize wrong can definitely destroy
your performance, maybe producing numbers as bad as you're seeing.
I won't claim that Berkeley DB is easy to tune, though.

-Barry