Convert a text list to text array? Was: Denormalizing during select

The email at the bottom gave me an idea, but it doesn't quite work:

CREATE AGGREGATE accumulate(  BASETYPE = text,  SFUNC = textcat,  STYPE = text,  INITCOND = '' );
--
SELECT ('{' || ltrim(accumulate(',' || tablename),',') || '}') as cruft FROM pg_tables  WHERE hasindexes = 'f';
           cruft
--------------------------- {pg_xactlock,pg_listener}
(1 row)

This produces somthing that looks like it could be able to be converted into 
an array but I cant figure out how to make it work.



Guy

Edmund Lian wrote:
> Jeff and Josh,
> 
> I found this example in "Practical PostgreSQL"... will it do the job?
> 
> """
> The following example defines an aggregate function named sum(), for
> use with the text data type. This aggregate calls the
> textcat(text,text) function built into PostgreSQL to return a
> concatenated "sum" of all the text found in its input values:
> 
> booktown=# CREATE AGGREGATE sum ( BASETYPE = text,
> booktown(#                        SFUNC = textcat,
> booktown(#                        STYPE = text,
> booktown(#                        INITCOND = '' );
> CREATE
> booktown=# SELECT sum(title || ' ') FROM books WHERE title ~ '^L';
...snip...