bsddb.open additional arguments

Question

The bsddb module has three ways to open a db-file:

bsddb.hashopen(filename[, flag[, mode[, pgsize[, ffactor[, nelem[, cachesize[, lorder[, hflags]]]]]]]])
bsddb.btopen(filename[, flag[, mode[, btflags[, cachesize[, maxkeypage[, minkeypage[, pgsize[, lorder]]]]]]]])
bsddb.rnopen(filename[, flag[, mode[, rnflags[, cachesize[, pgsize[, lorder[, rlen[, delim[, source[, pad]]]]]]]]]])

The documentation says:

The other arguments (excluding filename and flag) are rarely used and are just passed to the low-level dbopen function. Consult the Berkeley DB documentation for their use and interpretation.

But I haven't found the meaning of those arguments anywhere. Anyone knows the usage of this arguments? I think they may be useful to improve the performance of my db-file, I mean, get and set data faster.

Answer 1

Looking at the C API reference I see some documentation (but indeed it's hard to find). For example, for bsddb.hashopen:

• mode: DB->open()
• pgsize: DB->set_pagesize(), DB->get_pagesize()
• ffactor: DB->set_h_ffactor(), DB->get_h_ffactor()
• nelem: DB->set_h_nelem(), DB->get_h_nelem()
• cachesize: DB->set_cachesize(), DB->get_cachesize()
• lorder: DB->set_lorder(), DB->get_lorder()
• hflags (not sure about this one, sorry)