From: | Rich Cullingford <rculling(at)sysd(dot)com> |
---|---|
To: | pgsql-interfaces(at)postgresql(dot)org |
Subject: | Problems creating indexes with IMMUTABLE functions |
Date: | 2004-06-16 15:49:00 |
Message-ID: | 40D06BEC.3060102@sysd.com |
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Lists: | pgsql-interfaces |
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(at)sysd(dot)com
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