Обсуждение: problem with arrays

Hi,

I'm trying to convert some tables from version 6.2 to 6.4.2 but I have
problems with arrays. The old table definition was:
 create table a (x int4,y char8,z char8[] );

Now, because the char8 datatype has been removed from postgres, I suppose
I should use char(8) or varchar(8):
 create table a (x int4,y char(8),z char(8)[] );

or
 create table a (x int4,y varchar(8),z varchar(8)[] );

but when I try the above definitions I get the following errors:

dz=> create table a (
dz->     x int4,
dz->     y char(8),
dz->     z char(8)[]
dz-> );
ERROR:  type name lookup of _bpchar failed

dz=> create table a (
dz->     x int4,
dz->     y varchar(8),
dz->     z varchar(8)[]
dz-> );
ERROR:  type name lookup of _varchar failed

Also trying to define the _varchar or _bpchar types fails, so it seems that
the conversion from 6.2 to 6.4 is not possible for many data types.
Any suggestion?

-- 
Massimo Dal Zotto

+----------------------------------------------------------------------+
|  Massimo Dal Zotto               email: dz@cs.unitn.it               |
|  Via Marconi, 141                phone: ++39-0461534251              |
|  38057 Pergine Valsugana (TN)      www: http://www.cs.unitn.it/~dz/  |
|  Italy                             pgp: finger dz@tango.cs.unitn.it  |
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> Also trying to define the _varchar or _bpchar types fails, so it seems 
> that the conversion from 6.2 to 6.4 is not possible for many data 
> types. Any suggestion?

That sucks. afaik the only data types affected are the fixed-maximum
with variable-length strings. There was a comment in gram.y from Jolly
regarding the possibility for allowing bpchar and varchar into arrays,
though she explicitly disallowed it. I had thought that this code is
still in effect.

I'm not certain how much you have looked at this, but the leading
underscore is a Postgres convention for array data types. The trick to
allowing bpchar, varchar, and perhaps numeric types into arrays is
passing along the element dimensions. I haven't looked at whether that
already happens.

In the meantime, you can try using the text type instead. I know it
doesn't have an 8-byte maximum length, but it is allowed in arrays...
                     - Tom