On 2/27/17 10:37 AM, Tom Lane wrote:
2. Implicit user defined type casts are not applied for COALESCE operator:
That has nothing to do with whether the cast is user-defined.  It has to
do with not wanting to automatically unify types across type-category
boundaries (in this case, numeric vs. composite categories).  That's per
step 4 here:


and it's not an easy thing to get rid of because if you're considering
more than one type category then the heuristic about preferring "preferred
types" breaks down --- how do you know which category's preferred type to

FWIW, while working on a variant type I wished there was a way to preempt built-in type resolution when dealing with a particular type. I was specifically interested in function calls, which IIRC is handled by a single function and a helper. Exporting those two and providing a hook would have done the trick in my case.
Jim Nasby, Data Architect, Blue Treble Consulting, Austin TX
Experts in Analytics, Data Architecture and PostgreSQL
Data in Trouble? Get it in Treble! http://BlueTreble.com
855-TREBLE2 (855-873-2532)

Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:

Reply via email to