[Chennaipy] October 2015 Meetup Minutes

[Gaurav Sehrawat]

Hi everyone,


October Meet-up Minutes
--------------

Meet-up held on sunny pleasant day, with auditorium filled with audience
ready for talks as Vijay Kumar outlined the purpose of meet-up and agenda.
First talk was given by Abishek Postgresql "EXPLAIN". He started with
general audience poll on query optimization and query performance. He then
explain the usage of "EXPLAIN" which verify our speculation and gives us
cost of query while "EXPLAIN ANALYSE" actually runs the query and gives
cost of query. He explained the anatomy of "EXPLAIN" output and described
startup cost and end cost, where end cost is what we generally take into
consideration.
His talks consisted riddles in form of audience polls. One riddle was with
filters whether "WHERE" would result in low cost or not. Infact "WHERE"
clause increases the cost. Another riddle followed, whether creating
"INDEX" on query would optimize the query or not. Result was surprising
since "INDEX" didn't reduce the cost, it's because low cardinality indexes
are ignored. Next quiz was on "JOIN", adding "INDEX" on "JOIN" clause also
doesn't improve the cost. In fact "JOIN" doesn't use index in any step, to
 improve efficiency for "JOIN" better idea would be to use filter clause on
one of the table.
The last quiz included "ORDER BY", adding "INDEX" while using "ORDER BY"
clause really improves the cost, which was the key take away from the talk.

Next talk by amjith(@amjithr) complemented the previous one in huge way by
adding CLI tool for postgresql queries. He is the author of pgcli(pgcli.com)
and mycli(mycli.net). He right away got into demo of pgcli. He demoed auto
completion feature with fuzzylogic completion. Syntax highlight and meta
commands completion were also incentives of pgcli. PGCLI don't need
semicolons for one line commands while multiline mode needs them.
Talk was purpose wasn't to introduce to his tools, he wanted to dissipate
knowledge on building tools for modern CLI. He introduced tools which would
help in building on CLI tools including PTPYTHON which is awesome python
repl, WHARFEE which is docker shell interface, SAWS which is wonderful for
AWS shell interface and PYVIM which is Vim clone in Python. He further
introduced PROMPT TOOLKIT which is helpful in auto-completion and PYGMENTS
which  is helps in syntax highlighting. He also introduces fuzzy-finder
algorithm built by him and a blog post regarding the same. CLICK is also
nice tool for CLI helper methods. He concluded the talk with question from
audience and his contact details.

Next talk was by HariPriya Bhaskar on OpenCV. She started her talk with an
inspiring self-driving car video which has application of OpenCV. She then
headed over to short demo of object tracking using HSV value parameter. She
then explained the corresponding code used in the demo of object tracking.
She ended her talk with another video on future concept of applications of
OpenCV in augmented reality domain. On taking questions from audience she
in-depth explained the "GAIT" analysis in her project, in her clinical
project she used handy-cam and OpenCV for tracking movement of patient to
give them feedback. Shrayas further added to info about "GAIT" analysis
used by professional athletes.

The last talk was by open source rock-star aka Shakthi Kannan. His talk was
on "Pretty Printing in Python" i.e 3D printing using python. He showed
Prusa Mendel Hardware which he uses. Motivation of talk was to build stuff
by yourself without any need proprietary software and hardware. He showed
the SUPERMAN and BATMAN logo he built with the printer. He quickly dived
into the software he used for giving instruction to printer. He pointed out
the need for STL as end goal for draw the object. Gcode is sent to arduino
which handles the further instructions. He then introduced suite for 3D
printing like "printrun" and "Skeinforge". He also mentioned "Blender" for
3D modelling, Meshlab clould for real object and "pylatscan" for scanning
real objects and "rep rap" and "blenderpython".
He concluded his talk with credits to people on Internet and his colleagues
and interns who helped him and mentions of IRC channels to get help from.

Next up was for lightning talks, where Shakthi Kannan gave two presentation
where one consisted of 3d printing stuff. Another one was awesome rhymes
that are going to be prevalent to future software developers.
Then I(Gaurav) gave a talk a talk on making reveal.js slides using
"Jupyter" aka "Ipython", without going through any hassle.
Further Abhishek gave concerning talk about Volkswagen scandal and how
developers should be aware and be responsible of their actions and code.

Then Vijay gave closing note of the meet-up with due gratitude to sponsors,
IMSc and participants. We then had a group photos which concluded the
evening with discussion.



Thanks
P.S : Correct anything I got wrong.
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