Re: PoC/WIP: Extended statistics on expressions

On 1/22/21 3:29 AM, Justin Pryzby wrote:
> This already needs to be rebased on 55dc86eca.
> 
> And needs to update rules.out.
> 

Whooops. A fixed version attached.

> And doesn't address this one:
> 
> On Sun, Jan 17, 2021 at 10:53:31PM -0600, Justin Pryzby wrote:
>> | postgres=# CREATE TABLE t(i int);
>> | postgres=# CREATE STATISTICS s2 ON (i+1) ,(i+1+0) FROM t;
>> | postgres=# \d t
>> |                  Table "public.t"
>> |  Column |  Type   | Collation | Nullable | Default
>> | --------+---------+-----------+----------+---------
>> |  i      | integer |           |          |
>> | Indexes:
>> |     "t_i_idx" btree (i)
>> | Statistics objects:
>> |     "public"."s2" (ndistinct, dependencies, mcv) ON  FROM t
>>
>> on ... what ?
> 

Umm, for me that prints:

test=# CREATE TABLE t(i int);
CREATE TABLE
test=# CREATE STATISTICS s2 ON (i+1) ,(i+1+0) FROM t;
CREATE STATISTICS
test=# \d t
                  Table "public.t"
  Column |  Type   | Collation | Nullable | Default
--------+---------+-----------+----------+---------
  i      | integer |           |          |
Statistics objects:
     "public"."s2" ON ((i + 1)), (((i + 1) + 0)) FROM t

which I think is OK. But maybe there's something else to trigger the 
problem?


regards

-- 
Tomas Vondra
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