Simplified and Extended "Updating by Reference" Section in Joins Vignette

[venom1204]

Simplified and extended the Updating by Reference section in the Joins in data.table vignette.
closes #6846
in this i

• Added a simpler one-to-one update example for clarity.
• Provided an efficient solution for updating multiple columns using mget(cols), reducing unnecessary copies.
• Clarified RIGHT JOIN limitations and how := modifies x in place but does not update i.
• Mentioned performance improvements observed in large datasets.

@jangorecki can you please review this when you have time and suggest me if any changes are needed
thank you

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 98.59%. Comparing base (6aa99f5) to head (5a3f19c).
Report is 17 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #6847   +/-   ##
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  Coverage   98.59%   98.59%           
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  Files          79       79           
  Lines       14661    14665    +4     
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+ Hits        14455    14459    +4     
  Misses        206      206           

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[jangorecki]

I think it is best to ping author of this vignette. I haven't had yet opportunity to read the original version.

[MichaelChirico]

I'm not sure we've cleanly explained the difference between this join and the previous one. The only difference I see is tail() vs. last(), am I missing something?

IIUC the difference between tail() and last() would be that last() can skip NA values, right?

[MichaelChirico]

are these valid {knitr} chunk names? regardless, please use machine-readable names (a la https://style.tidyverse.org/files.html)

[venom1204]

@lucasmation @MichaelChirico
I've refined and modified the section to align with the issue requirements. Kindly review and share any suggestions when you have time.

thanks.

[Advaitgaur004]

@venom1204, what is the update on this, have you tested the code .

data.table::last(c(1, NA))
# [1] NA

data.table::data.table(a = c(1, 1, 2, 2), b = c(1, NA, 2, NA))[, last(b), by=a]
#        a    V1
#    <num> <num>
# 1:     1    NA
# 2:     2    NA

[venom1204]

@MichaelChirico I’ve minimized the changes I introduced while ensuring they contain sufficient information and remain easy to understand. Could you review them and let me know if any further simplification is needed, or if they are good as they are?

[venom1204]

@iagogv3 I’ve incorporated your suggestions into my latest version. Could you review the updates and let me know if any further improvements are needed? Your feedback would be greatly appreciated!
thank you.