Amit-san, On Wed, Mar 6, 2019 at 5:38 AM, Amit Langote wrote: ... > > I didn't investigate that problem, but there is another memory > > increase > issue, which is because of 0003 patch I think. I'll try to solve the latter > issue. > > Interested in details as it seems to be a separate problem.
I solved this problem.
I think we don't need to do list_copy in the below code.
+ /*
+ * No need to copy of the RTEs themselves, but do copy the List
+ * structure.
+ */
+ subroot->parse->rtable = list_copy(rtable_with_target);
Because subroot->parse->rtable will be copied again by:
subroot->parse = (Query *)
adjust_appendrel_attrs(parent_root,
- (Node *)
parent_parse,
+ (Node *)
subroot->parse,
1, &appinfo);
So I modified the code and did test to confirm memory increasement don't
happen. The test and results are below.
[test]
* Create partitioned table with 1536 partitions.
* Execute "update rt set a = random();"
[results]
A backend uses below amount of memory in update transaction:
HEAD: 807MB
With v26-0001, 0002: 790MB
With v26-0001, 0002, 0003: 860MB
With v26-0003 modified: 790MB
I attached the diff of modification for v26-0003 patch which also contains some
refactoring.
Please see if it is ok.
(Sorry it is modification for v26 patch though latest ones are v28.)
--
Yoshikazu Imai
v26-0003-solving-memory-increasement-problem.diff
Description: v26-0003-solving-memory-increasement-problem.diff
