On Fri, Nov 16, 2018 at 08:38:26AM -0600, Justin Pryzby wrote:
> Are you referring to this  a future commit ?
this OR a future commit

> The table is not too special, but was probably ALTERed to add columns a good
> number of times by one of our processes.  It has ~1100 columns, including
> arrays, and some with null_frac=1.  I'm trying to come up with a test case
> involving column types and order.

I don't have a failing test case yet but here's what the columns look like:

ts=# SELECT attnum, null_frac, atttypid::regtype, attnotnull, attname, attalign 
, attstorage, attbyval, attlen, attislocal FROM pg_stats s JOIN pg_attribute a 
USING(attname) JOIN pg_class c ON s.tablename=c.relname WHERE c.oid=a.attrelid 
AND tablename='daily_eric_umts_rnc_utrancell_view_201804' AND (attnotnull OR 
null_frac>0.9 OR atttypid::regtype::text LIKE '%[]' OR NOT 
atttypid::regtype::text~'int$|integer|double|numeric' OR attlen=-1 OR NOT 
attbyval OR atthasmissing OR attisdropped OR attnum BETWEEN 80 AND 99) ORDER BY 
1;

 attnum | null_frac |          atttypid           | attnotnull |                
     attname                     | attalign | attstorage | attbyval | attlen | 
attislocal
--------+-----------+-----------------------------+------------+-------------------------------------------------+----------+------------+----------+--------+------------
      1 |         0 | timestamp without time zone | t          | start_time     
                                 | d        | p          | t        |      8 | t
      2 |         0 | integer                     | t          | site_id        
                                 | i        | p          | t        |      4 | t
      3 |         0 | integer                     | t          | sect_id        
                                 | i        | p          | t        |      4 | t
      4 |         0 | integer                     | t          | rnc_id         
                                 | i        | p          | t        |      4 | t
      5 |         0 | text                        | t          | utrancell      
                                 | i        | x          | f        |     -1 | t
     30 |         1 | bigint                      | f          | 
dl_alt_chcode_alloc                             | d        | p          | t     
   |      8 | t
     31 |         1 | integer                     | f          | 
dl_alt_chcode_alloc_min                         | i        | p          | t     
   |      4 | t
     32 |         1 | integer                     | f          | 
dl_alt_chcode_alloc_max                         | i        | p          | t     
   |      4 | t
     45 |         0 | integer[]                   | f          | 
dch_ul_rlc_user_tput_samples                    | i        | x          | f     
   |     -1 | t
     46 |         0 | integer[]                   | f          | 
dch_ul_rlc_user_tput_samples_min                | i        | x          | f     
   |     -1 | t
     47 |         0 | integer[]                   | f          | 
dch_ul_rlc_user_tput_samples_max                | i        | x          | f     
   |     -1 | t
     51 |         0 | numeric                     | f          | 
ps_int_sum_latency_2                            | i        | m          | f     
   |     -1 | t
     69 |         0 | numeric                     | f          | 
mbytes_ul_srb_only_eul                          | i        | m          | f     
   |     -1 | t
[...]
     87 |         0 | numeric                     | f          | 
mbytes_dl_active_cs57                           | i        | m          | f     
   |     -1 | t
     88 |         0 | numeric                     | f          | 
mbytes_dl_active_cs57_min                       | i        | m          | f     
   |     -1 | t
     89 |         0 | numeric                     | f          | 
mbytes_dl_active_cs57_max                       | i        | m          | f     
   |     -1 | t

If I query for cs57, it doesen't crash (in 500ms), but if I query for the next
column, cs57_min, it does (in 18000ms).

Here's a new error message instead of a crash this time:
ts=# SET jit=on;SET jit_above_cost=0;explain(analyze on,verbose off) SELECT 
b.mbytes_dl_active_cs57_min FROM 
child.daily_eric_umts_rnc_utrancell_view_201804 a JOIN 
child.daily_eric_umts_rnc_utrancell_view_201804 b USING(start_time,sect_id) 
WHERE a.start_time BETWEEN '2018-04-30' AND '2018-05-04' AND b.start_time 
BETWEEN '2018-04-30' AND '2018-05-04';
SET
SET
ERROR:  out of memory            
DETAIL:  Failed on request of size 425170160 in memory context 
"HashBatchContext".

Here's verbose output you requested, sans expressions:

ts=# SET jit=on;SET jit_above_cost=0;explain(analyze off,verbose) SELECT 
b.mbytes_dl_active_cs57_min FROM 
child.daily_eric_umts_rnc_utrancell_view_201804 a JOIN 
child.daily_eric_umts_rnc_utrancell_view_201804 b USING(start_time,sect_id) 
WHERE a.start_time BETWEEN '2018-04-30' AND '2018-05-04' AND b.start_time 
BETWEEN '2018-04-30' AND '2018-05-04';
SET
SET
                                                                                
   QUERY PLAN                                                                   
                
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Hash Join  (cost=2224.45..4491.19 rows=22 width=3)
   Output: b.mbytes_dl_active_cs57_min
   Hash Cond: ((a.start_time = b.start_time) AND (a.sect_id = b.sect_id))
   ->  Index Only Scan using 
daily_eric_umts_rnc_utrancell_view_201804_unique_idx on 
child.daily_eric_umts_rnc_utrancell_view_201804 a  (cost=0.29..2214.33 rows=656 
width=12)
         Output: a.start_time, a.site_id, a.rnc_id, a.sect_id, a.utrancell
         Index Cond: ((a.start_time >= '2018-04-30 00:00:00'::timestamp without 
time zone) AND (a.start_time <= '2018-05-04 00:00:00'::timestamp without time 
zone))
   ->  Hash  (cost=2214.33..2214.33 rows=656 width=15)
         Output: b.mbytes_dl_active_cs57_min, b.start_time, b.sect_id
         ->  Index Scan using 
daily_eric_umts_rnc_utrancell_view_201804_unique_idx on 
child.daily_eric_umts_rnc_utrancell_view_201804 b  (cost=0.29..2214.33 rows=656 
width=15)
               Output: b.mbytes_dl_active_cs57_min, b.start_time, b.sect_id
               Index Cond: ((b.start_time >= '2018-04-30 00:00:00'::timestamp 
without time zone) AND (b.start_time <= '2018-05-04 00:00:00'::timestamp 
without time zone))
 JIT:
   Functions: 19
   Options: Inlining false, Optimization false, Expressions true, Deforming true

If I query instead for a.mbytes_dl_active_cs57_min, I get no crash (yet).

Justin

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