The following bug has been logged on the website:
Bug reference: 16171
Logged by: Mahadevan Ramachandran
Email address: mahadevan@rapidloop.com
PostgreSQL version: 12.1
Operating system: any
Description:
Refer src/backend/commands/explain.c, version 12.1.
When a plan node has children, the function ExplainNode starts a JSON array
with the key "Plans" (line 1955), like so:
"Plans": [
with the intention of creating an array of "Plan" objects, one for each
child:
"Plans": [
{ .. a child plan goes here ..},
{ .. a child plan goes here ..}
]
However, if the node (the current, parent one) is of a certain type (see
switch at line 1975), then ExplainMemberNodes is called, which does this
(lines 3335-6):
if (nsubnodes < nplans)
ExplainPropertyInteger("Subplans Removed", NULL, nplans - nsubnodes,
es);
This can potentially cause a malformed JSON output like this:
"Plans": [
{ .. a child plan goes here ..},
"Subplans Removed": 5,
{ .. a child plan goes here ..}
]
I don't have a sample explain output that exhibits this error, this was
found while reviewing the code.
