BUG #18520: Different results when analyze a relation with UDT.

Started by PG Bug reporting formalmost 2 years ago2 messagesbugs
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#1PG Bug reporting form
noreply@postgresql.org

The following bug has been logged on the website:

Bug reference: 18520
Logged by: zhou zhanghua
Email address: 2467882606@qq.com
PostgreSQL version: 17beta1
Operating system: Ubuntu 22.04
Description:

When analyzing a relation with UDT, an error will be encountered if there is
a join before the analyze stmts. Error message is "ERROR: missing support
function 1(16386,16386) in opfamily 16392".

to reproduce:
```
create type foo_type as (a float8, b float8);

CREATE FUNCTION foo_type_less(foo_type, foo_type) RETURNS bool
AS
$$
SELECT true::boolean;
$$ LANGUAGE SQL IMMUTABLE STRICT;

CREATE OPERATOR < (
leftarg = foo_type, rightarg = foo_type,
procedure = foo_type_less,
commutator = >=
);

CREATE FUNCTION foo_type_eq(foo_type, foo_type) RETURNS bool
AS
$$
SELECT false::boolean;
$$ LANGUAGE SQL IMMUTABLE STRICT;

CREATE OPERATOR = (
leftarg = foo_type, rightarg = foo_type,
procedure = foo_type_eq,
commutator = =
);

CREATE OPERATOR CLASS foo_type_btreeopclass
DEFAULT FOR TYPE foo_type using btree as
OPERATOR 1 <;

CREATE FUNCTION foo_type_hash(foo_type) RETURNS int4
AS
$$
SELECT 1;
$$ LANGUAGE SQL IMMUTABLE STRICT;

CREATE OPERATOR CLASS foo_type_hashopclass
DEFAULT FOR TYPE foo_type using hash as
operator 1 = ,
function 1 foo_type_hash(foo_type);

create table foo_type_table(a foo_type);

insert into foo_type_table values ((1,2)),((3,4)),((5,6));

-- ERROR: missing support function BTORDER_PROC(foo_type,foo_type) in
opfamily foo_type_btreeopclass
select * from foo_type_table a, foo_type_table b where a.a = b.a;
analyze foo_type_table;

-- another session
-- success
analyze foo_type_table;

```

I tried to debug this different behavior, compute_scalar_stats is used when
execute join before analyze, compute_trivial_stats is used when no join
before analyze. This may because of the hash join load some thing into type
cache, leading std_typanalyze choose different functions.

#2Tom Lane
tgl@sss.pgh.pa.us
In reply to: PG Bug reporting form (#1)
Re: BUG #18520: Different results when analyze a relation with UDT.

PG Bug reporting form <noreply@postgresql.org> writes:

When analyzing a relation with UDT, an error will be encountered if there is
a join before the analyze stmts. Error message is "ERROR: missing support
function 1(16386,16386) in opfamily 16392".

What your example shows is a buggy (very incomplete) operator class.
This is not a Postgres bug.

regards, tom lane