Re: Bug in ExecModifyTable function and trigger issues for foreign tables

Etsuro Fujita <fujita.etsuro@lab.ntt.co.jp>

From: Etsuro Fujita <fujita.etsuro@lab.ntt.co.jp>
To: Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>, Ildus Kurbangaliev <i.kurbangaliev@postgrespro.ru>
Cc: Dilip Kumar <dilipbalaut@gmail.com>, PostgreSQL Hackers <pgsql-hackers@postgresql.org>, Robert Haas <robertmhaas@gmail.com>
Date: 2017-06-05T08:25:27Z
Lists: pgsql-hackers

Attachments

On 2017/06/02 18:10, Etsuro Fujita wrote:
> On 2017/05/16 21:36, Etsuro Fujita wrote:
>> One approach I came up with to fix this issue is to rewrite the 
>> targetList entries of an inherited UPDATE/DELETE properly using 
>> rewriteTargetListUD, when generating a plan for each child table in 
>> inheritance_planner.  Attached is a WIP patch for that.  Maybe I am 
>> missing something, though.
> 
> While updating the patch, I noticed the patch rewrites the UPDATE 
> targetList incorrectly in some cases; rewrite_inherited_tlist I added to 
> adjust_appendrel_attrs (1) removes all junk items from the targetList 
> and (2) adds junk items for the child table using rewriteTargetListUD, 
> but it's wrong to drop all junk items in cases where there are junk 
> items for some other reasons than rewriteTargetListUD.  Consider junk 
> items containing MULTIEXPR SubLink.  One way I came up with to fix this 
> is to change (1) to only remove junk items with resname; since junk 
> items added by rewriteTargetListUD should have resname (note: we would 
> need resname to call ExecFindJunkAttributeInTlist at execution time!) 
> while other junk items wouldn't have resname (see 
> transformUpdateTargetList), we could correctly replace junk items added 
> by rewriteTargetListUD for the parent with ones for the child, by that 
> change.  I might be missing something, though.  Comments welcome.

I updated the patch that way.  Please find attached an updated version.

Other changes:
* Moved the initialization for "tupleid" I added in ExecModifyTable as 
discussed before, which I think is essentially the same as proposed by 
Ildus in [1], since I think that would be more consistent with "oldtuple".
* Added regression tests.

Anyway I'll add this to the next commitfest.

Best regards,
Etsuro Fujita

[1] 
https://www.postgresql.org/message-id/20170514150525.0346ba72%40postgrespro.ru

Commits

  1. Fix creation of resjunk tlist entries for inherited mixed UPDATE/DELETE.