Question about Array data type in PostgreSQL and their link with hash table concept

Hi,

I would like to ask a question about Array type. My question is somewhat a
comparison between
Oracle PL/SQL & PostgreSQL.

I was reading the online documentation at the following link about the
Array data type and
I read the following note:

http://www.postgresql.org/docs/9.3/interactive/arrays.html

> *Tip: Arrays are not sets; searching for specific array elements can be a
> sign of database misdesign. *
> *Consider using a separate table with a row for each item that would be an
> array element. *
> *This will be easier to search, and is likely to scale better for a large
> number of elements.*
>

Are arrays in PostgreSQL like associative arrays in Oracle PL/SQL hash
tables?, that is an
association between key & values? where the integer indexes stand in
reality for keys?

Thanks in advance,