core dump

I've two questions, they may or may not be related -
1. I copied the entire data directory [including
postgresql.conf, base, ...] from postgreSQL 7.3.2 (AIX4.3)
to the installation postgreSQL 7.3.4 (AIX5.1), the same filesystem
setup. I didn't do an dump/reload process
since the copy process is faster.

Is it OK to take this shortcut in postgreSQL? any side-effects?

2. The copied database with 7.3.4 pgsql and 7.3.2 data dir seems
running OK. But when I run the following query it causes core dump -
psql -d emrxdbs -At -F '|' -c "select cdi, doctypeid,
getdatatype(doctypeid) from document;"
>out

but the above query works on the older AIX4.3 postgreSQL7.3.2, and
if I run the following query it works on new AIX5.1 -
psql -d emrxdbs -At -F '|' -c "select cdi, doctypeid,
getdatatype(doctypeid) from document limit 10;" >out

strings core indicates some memory issues,
but the new AIX5.1 has far more memory than the old AIX4.3 -
...
SELECT relname FROM pg_catalog.pg_listener WHERE substr(relname,1,%d)='%s'
UNION SELECT '*'::name
pgSELECT relname FROM pg_catalog.pg_class WHERE relkind='r' and
substr(relname,1,%d)='%s' and pg_catalog.pg_t
able_is_visible(oid) UNION SELECT 'FULL'::name UNION SELECT 'ANALYZE'::name
format
Tborder
Wexpanded
VERnull
fieldsep
tuples_only
title
ATtableattr
LLpager
EXrecordsep
IBMout of memory
ISELECT c1.relname FROM pg_catalog.pg_class c1, pg_catalog.pg_class c2,
pg_catalog.pg_index i WHERE c1.oid=i.
indrelid and i.indexrelid=c2.oid and c2.relname='%s' and
pg_catalog.pg_table_is_visible(c2.oid)
BINARY
...
IBM\out
IBM\s
I\write
I%s LIMIT %d;
out of memory
ION_ERROR_STOP
IBIGNOREEOF
IBQUIET
IB\q
IUse "\q" to leave %s.
IECHO
IBMall
abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_
%.*s%s%s
IBM
IBMSINGLELINE
@(#)61
1.14 src/bos/usr/ccs/lib/libc/__threads_init.c, libcthrd, bos510 7/11/00
12:04:14
set client_encoding to '%s'
xrealloc
xmalloc
%s: out of virtual memory
...

Any thoughts?

thanks.
johnl