Make postgres full text search (tsvector) act like ILIKE to search inside words?
Are you aware of trigram search, provided by the additional module pg_trgm? That seems more appropriate for your use case than text search.
With a trigram index in place (GIN or GiST) you can use your original ILIKE predicate and get index support for it. You need Postgres 9.1+ for that.
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