[ARROW-17184] [R] Investigate Nodes missing from ExecPlan print out for nested queries

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Not A Problem
• Component/s: R
• External issue URL: https://github.com/apache/arrow/issues/32479
• Assignee: Unassigned
• Reporter: Dragoș Moldovan-Grünfeld
• Created: 22/Jul/22 11:00
• Updated: 11/Jan/23 11:49
• Resolved: 16/Sep/22 14:45

Description

Update: We currently do not print a plan for nested queries as that would involve the execution of the inner most query / queries. That is likely the reason why, in the chunk below, we do not see the filter and arrange nodes.

==========================

Original description:

Now that we can print an ExecPlan (ARROW-15016), we can investigate unexpected outputs. With the following chunk of code:

mtcars %>%
  arrow_table() %>%
  select(mpg, wt, cyl) %>% 
  filter(mpg > 20) %>%
  arrange(desc(wt)) %>%
  head(3) %>%
  show_exec_plan()
#> ExecPlan with 3 nodes:
#> 2:SinkNode{}
#>   1:ProjectNode{projection=[mpg, wt, cyl]}
#>     0:SourceNode{}

• FilterNode disappears when head/tail are involved +
• we do not have additional information regarding the OrderBySinkNode
• the entry point is a SourceNode and not a TableSourceNode