[Monetdb-developers] mapi_fetch_reset

Stefan de Konink stefan at konink.de
Fri Oct 10 19:46:31 CEST 2008


-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA512

Hi,


Is it theoretically possible that the result set is too big for
mapi_fetch_reset to work, so it is actually not brought back to the
first result? (Opposed to the first result in the cache)


I'm having the following optimalisation issue; I can request a set of
points in one go, but I need to reprocess them in two outputs.

- - I can place two queries, second one with a subselect
- - I can place one query with a subselect (process it twice, see question
one)
- - I can store the outcome of query one, and then use an IN (...) pattern
build from the first query output.
- - I can store desired outcome in a temporary buffer, and place it on the
end, using the one query subselect approach.


Option one uses two queries, sounds slow, option two is related to
quetion one, I have seen option 3 fail for huge sets, Option 4 can take
up twice as much memory.


Suggestions? :)



Stefan
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.9 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iEYEAREKAAYFAkjvlPcACgkQYH1+F2Rqwn3BPQCfTCjR/aHwJw/tUU09oCl+W5xq
1cEAniPMIFArgNJjOdKAgmH2TUZHWEpG
=l9k7
-----END PGP SIGNATURE-----




More information about the developers-list mailing list