You canot have constant time inserts into a B-Tree because of the inherent nature of the algorithm. Berkeley DB has either B-Tree or hashed indices. The unordered hashed indices are possibly what you measured. Note that B-Trees have the additional property that they maintain an order and thus are more useful in a database. JS
Julian Bui wrote: > Unless I did something wrong, I did observe constant time inserts in > Berkeley DB. Is it possible that I had constant time inserts into a btree > as my db grew because of the nature of my data? I was inserting records in > order of how they would be sorted by index. In other words, every inserted > record's indexed field was greater than the previous one. Perhaps the db > made use of this feature of my inserts because I set sortedDuplicates() on > which allows for a clustered index. > > On Thu, Oct 30, 2008 at 6:11 PM, Alex Scotti <[EMAIL PROTECTED]> wrote: > > >>On Oct 29, 2008, at 4:59 AM, Julian Bui wrote: >> >> >>>Hi everyone, >>> >>>First off, I'm a database and sqlite newbie. I'm inserting many many >>>records and indexing over one of the double attributes. I am seeing >>>my insert times slowly degrade as the database grows in size until >>>it's unacceptable - less than 1 write per millisecond (other databases >>>have scaled well). I'm using a intel core 2 duo with 2 GB of ram and >>>an ordinary HDD. >>> >>>I am trying to figure out why some of the other databases (firebird, >>>mysql, berkeley db) have provided constant insert speeds whereas >>>sqlite has not. >> >>i can tell you firsthand that berkeley db does not provide anything >>like constant time for random inserts into a btree as it's size grows. >> >> >> >>_______________________________________________ >>sqlite-users mailing list >>sqlite-users@sqlite.org >>http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >> > > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
