The –fast option in the tool gdx2sqlite is sometimes really helpful. This is especially the case if there are many tables:
The column avg table size indicates the average number of rows in a table. It looks like if this number is small the effect of –fast is most pronounced.
The –fast option will issue PRAGMA synchronous = OFF and PRAGMA journal_mode = MEMORY to SQLite.
Here is a nice presentation on SQLite:
Interesting tidbit: statistics on SQLite: 2e9 running instances, 5e5 applications (May 2014).