The FTS5 prefix index documentation[1] seems to not be working. I've tried with SQLite 3.9.0 and 3.10.0 (2015-11-06) and both show the same error messages.
Examples: sqlite> CREATE VIRTUAL TABLE ft USING fts5(a, b, prefix='2 3'); Error: malformed prefix=... directive sqlite> CREATE VIRTUAL TABLE ft USING fts5(a, b, prefix=2, prefix=3); Error: multiple prefix=... directives What does appear to work is using a comma: sqlite> CREATE VIRTUAL TABLE ft USING fts5(a, b, prefix='2,3'); sqlite> .schema ft CREATE VIRTUAL TABLE ft USING fts5(a, b, prefix='2,3'); 1: https://sqlite.org/fts5.html#section_4_2
