All,
It appears that the use of certain kinds of functions on columns to
create indexes is disabled in PG 7.4.1 (on RH 8.0 3.2-7). An attempt to
create an index on the concatenation of a date and an int gives:
sysd=> create index bnoz_idx on evidence (bnoz(alert_date, period));
ERROR: functions in index expression must be marked IMMUTABLE
although:
sysd=> select provolatile, prosrc from pg_proc where proname='bnoz'; provolatile | prosrc
-------------+------------------------------------------------------------------------------------------------------------------------------------------------
i |
declare hr alias for $2; pad text := '0';
begin if hr<10 then return $1 || ' ' || pad || hr; end if; return $1 || ' ' || hr;
end;
That is, the function is IMMUTABLE according to the catalog. The problem
appears to be with the date field:
sysd=> create index bnoz_idx on evidence ((alert_date || ' ' || period));
ERROR: functions in index expression must be marked IMMUTABLE
though:
sysd=> create index bnoz_idx on evidence ((service || ' ' || period));
CREATE INDEX
works, where 'service' is a text column.
I've searched the lists for indciations of this problem, and have failed
to find anything. Does this ring a bell with anyone?
Sincerely, Rich Cullingford rculling@sysd.com
