| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | "Christopher Kings-Lynne" <chriskl(at)familyhealth(dot)com(dot)au> |
| Cc: | "Hackers" <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: Changing column types... |
| Date: | 2002-04-04 15:34:42 |
| Message-ID: | 23600.1017934482@sss.pgh.pa.us |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
"Christopher Kings-Lynne" <chriskl(at)familyhealth(dot)com(dot)au> writes:
> 3. Is there any way of checking pg_type to check that two types are binary
> compatible and can be substiuted in this way?
Binary compatibility is not represented in pg_type (which is a shortcoming).
You have to use the IsBinaryCompatible() routine provided by
parse_coerce.h.
> 4. Is there any worth in me submitting a patch that will allow rudimentary
> column type changing, so long as the types are binary compatible???
Hmm. Seems like that case, and the various ones involving adjustment of
char/varchar length by hacking atttypmod, would be useful to support via
ALTER COLUMN even if we don't have a full implementation. Essentially
this would be taking the existing folklore about safe ways to hack
pg_attribute and reducing them to code --- why not do it?
regards, tom lane
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Tom Lane | 2002-04-04 15:57:39 | Re: Bidirectional hard joins (fwd) |
| Previous Message | Hannu Krosing | 2002-04-04 15:31:47 | Re: Bidirectional hard joins (fwd) |