-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 07/30/2011 02:29 PM, Mr. Puneet Kishor wrote: > could you please tell what this other "JSON database server product" was?
MongoDB. A major difference between MongoDB and CouchDB is how they store data. CouchDB uses an append only structure - data is not modified in place. If for example you add a record then that record is appended plus all the intermediate btree pages affected up to the root which is how you can end up with so much disk space being used. Reads don't require locking because they start at the most recent root page working with that and earlier pages in the file. Occasionally you have to run a compaction which creates a new structure copying only the used pages from the existing one. Replication is easy because you already have a log and can replay that to peers plus updates automatically track DAG information. MongoDB (like SQLite) modifies in place. It also lacks a pager layer - instead the database file is memory mapped and it is up to the operating system to page contents in and out. It also limits your database size to 2GB with 32 bit operating systems, although they could work around that. Roger -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iEYEARECAAYFAk40gqIACgkQmOOfHg372QSYqwCeLvrxsq9r4egvLuImOkF8P+Qw HUUAnA1U06VHVWLMs6eRPbTLo6P79NN4 =nHIW -----END PGP SIGNATURE----- _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
