Which non SQL Database ?

[John Nagle]

On 12/4/2010 8:44 PM, Monte Milanuk wrote:
> On 12/4/10 3:43 PM, Jorge Biquez wrote:
>
>> I do not see a good reason for not using Sqlite3 BUT if for some reason
>> would not be an option.... what plain schema of files would you use?
>
> Would shelve work?

     There are some systems for storing key-value pairs in files.

     Underneath "shelve" is some primitive database, dbm, gdbm or bsddb.
"bsddb" is deprecated and was removed from Python 3.x.  "dbm" has
some classic problems.  "gdbm" is an improved version of "dbm".
None of these handle access from multiple processes, or crash
recovery.  We're looking at 1979 technology here.

    SQLite works right when accessed from multiple processes.  SQLite
is the entry-level database technology for Python today.  It handles
the hard cases, like undoing transactions after a crash and
locking against multiple accesses.  Lookup performance is good;
simultaneous update by multiple processes, though, is not so
good.  When you have a web site that has many processes hitting
the same database, it's time to move up to MySQL or Postgres.

    There's a lot of interest in "non-SQL" databases for very
large distributed systems.  You worry about this if you're Facebook
or Google, or are running a big game server farm.

				John Nagle