Help: Function for splitting VARCHAR column and migrating its data to 2 new tables - Mailing list pgsql-sql

I am restructuring my DB schema and need help migrating data from 1
column of an existing table to two new tables.  I have some Java code
that can do this for me, but it's very slow, and I am now hoping I can
migrate this data with some clever SQL instead.

Here are my 3 tables:

user_data (existing, old table)
--------- id           (PK), user_id      (FK) keywords     VARCHAR(256)   -- this contains comma separated keywords
--e.g. "new york,san francisco, dallas, food"   -- also "keywords without strings are really just 1 keyword" add_date
 TIMESTAMP
 


So now I'm trying to migrate this "keywords" VARCHAR column to a more
normalized schema:

user_data_keyword (new lookup table to populate)
----------------- id           (PK) -- I may change PK to PK(user_data_id, keyword_id) user_data_id (FK) keyword_id
(FK)


keyword (new table to populate)
------- id           (PK) name         VARCHAR(64) NOT NULL UNIQUE add_date     TIMEZONE


I just found
http://www.postgresql.org/docs/current/static/functions-string.html ,
but if anyone could lend me a hand by getting me started with writing a
function for this, I'd really appreciate it.

Thanks,
Otis