Jeremy Bernstein wrote:
Although I didn't figure out a good way to do what I want, this is what I am now doing:
if (MDB_MAP_FULL while putting) { abort txn, close the database reopen the database @ larger mapsize perform some pruning of dead records commit txn, close the database reopen the database @ old mapsize try to put again }
At this point, the database is probably larger than the old mapsize. To handle that, I make a copy of the DB, kill the original, open a new database and copy the records from the old DB to the new one.
All of this is a lot more complicated and code-verbose than I want, but it works and seems to be reliable.
Nevertheless, if there's an easier way, I'm all ears. Thanks for your thoughts.
Use mdb_stat() before performing the _put(). If the total number of pages in use is large (whatever threshold you choose, e.g. 90%) then start pruning.
Look at the mdb_stat command's output to get an idea of what you're looking for.