2010/7/21 Robert Haas <robertmh...@gmail.com>: > On Wed, Jul 21, 2010 at 12:39 AM, Itagaki Takahiro > <itagaki.takah...@gmail.com> wrote: >> 2010/7/20 Pavel Stehule <pavel.steh...@gmail.com>: >>> here is a new version - new these functions are not a strict and >>> function to_string is marked as stable. >> >> We have array_to_string(anyarray, text) and string_to_array(text, text), >> and you'll introduce to_string(anyarray, text, text) and >> to_array(text, text, text). >> Do we think it is good idea to have different names for them? IMHO, we'd >> better use 3 arguments version of array_to_string() instead of the >> new to_string() ? > > The worst part is that the new names are not very mnemonic. > > I think maybe what we really need here is array equivalents of > COALESCE() and NULLIF(). It looks like the proposed to_string() > function is basically equivalent to replacing each NULL entry with the > array with a given value, and then doing array_to_string() as usual. > And it looks like the proposed to_array function basically does the > same thing as to_array(), and then replaces empty strings with NULL or > some other value. > > Maybe we just need a function array_replace(anyarray, anyelement, > anyelement) that replaces any element in the array that IS NOT > DISTINCT FROM $2 with $3 and returns the new array. That could be > useful for other things besides this particular case, too. >
I don't agree. Building or updating any array is little bit expensive. There can be same performance issue like combination array_agg and array_to_string versus string_agg. I am not against to possible name changes. But I am strong in opinion so current string_to_array and array_to_string are buggy and have to be deprecated. Regards Pavel p.s. can we use a names - text_to_array, array_to_text ? > -- > Robert Haas > EnterpriseDB: http://www.enterprisedb.com > The Enterprise Postgres Company > -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
