Comment 3 for bug 1546911

Tyler: no it isn't. The one argument version allows you to query for the existence of a particular named tokenizer. The two argument version is needed to register a new named tokenizer. When they disabled this they didn't offer an alternative for fts3/fts4 users, so the documentation just says to turn the feature back on if you need it, which is a bit unsatisfying.

It looks like there is a new API to register tokenizers using the new fts5 API, but that still seems to be under development so the entire backend is disabled in the current release:

    $ sqlite3 :memory:
    SQLite version 3.11.0 2016-02-15 17:29:24
    Enter ".help" for usage hints.
    sqlite> create virtual table f1 using fts5(a, content='');
    Error: no such module: fts5

It isn't clear this code is at a point where databases would be compatible release to release, so is probably not appropriate to even consider yet.

From a few web searches, I'm guessing this is the reason it was disabled:

http://chichou.0ginr.com/blog/1336/abuse-sqlite3-ext-to-bypass-php-security-restrictions

So it is a problem when an application runs untrusted SQL under the control of the attacker (and in this case, combined with untrusted PHP code under the control of the attacker). That seems like a pretty buggy application to start with.