Re: no partition pruning when partitioning using array type

On 2018-May-08, Amit Langote wrote:

> In HEAD, since we already fixed that case in e5dcbb88a15d [1] which is a
> different piece of code anyway, the patch only serves to improve the
> deparse output emitted by ruleutils.c for partition constraint expressions
> where pseudo-type partition key is involved.  The change can be seen in
> the updated test output for create_table test.

Actually, even in 11/master it also fixes this case:

alvherre=# explain update p set a = a || a where a = '{1}';
                        QUERY PLAN                        
──────────────────────────────────────────────────────────
 Update on p  (cost=0.00..54.03 rows=14 width=38)
   Update on p1
   Update on p2
   ->  Seq Scan on p1  (cost=0.00..27.02 rows=7 width=38)
         Filter: (a = '{1}'::integer[])
   ->  Seq Scan on p2  (cost=0.00..27.02 rows=7 width=38)
         Filter: (a = '{1}'::integer[])
(7 filas)

Because UPDATE uses the predtest.c prune code, not partprune.  So it's
not just some ruleutils beautification.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
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