Retrospective of start as a eleventh-year engineer, sixth-year blogger and fifth-year worker

Background

Ten years have been passed since I entered university. I always like science and engineering and other computer related and electronic stuffs since childhood. Include this year, I can briefly summarize like below.

• 11 years have passed since study major
• 6 years have passed since start tech blog
• 5 years have passed since go to work

A lot of time has passed and there were many events and learnings and changing of thinkings. I’m not sure it is good or bad to open this post to public… but I think it is good to write a retrospective as a major, blogger and worker. So many things are left in this new year so I’m going to write point and necessary things.

As a Major

Dream and Footprints

10 years have passed since I major computer and study hard in this field. As I wrote, I set a goal to major IT because I like electronic devices, science, engineering, computer related things and also good at those since little kid. I read many biography of a great person and wanted to be a great man who can contribute to country because I’m proud of my country. While growing up, I was inspired by Steve Job’s presentation and Jong-kyun Shin’s presentation. I’d like to be a man like them who speeches in front of people. By doing that I think I can keep my family, friends and make my country better.

So I entered my dream university and I took a dream major(computer). I studied hard and did many things with passion.

I think I had fun and worked passionately for 10 years. Recently I lost some of my passion… but except recent I liked it so much that there was nothing more interesting than this field.

Important Things in Life

I tried hard to become an executive in current company. Whatever other people say, I passionately find way to become it. The reason for becoming an executive is because I like my major and I think I can protect my family and friends and contribute to my country.

However recently I changed my mind after entered company. Family is one of the most important things in my life but I could not care them well. I have a dog. He is also my brother. Sad thing is that I could not recognize his right eye slowly become blind(Left eye is ok. Thanks to god.) and I did not carefully take care of my family. I can’t say it’s just because of work but the moment I felt this I realized that the most important thing to me is my family and people around me.

After that I wanted to take care of my family more, so I wanted to study veterinary medicine or medicine again. Of course I cannot go due to my 수능(Korea SAT) score but I seriously thought about trying again. I even searched transferring to the provinces because of veterinary medicine.

I think I could help my family in other way and my dog directly when they are sick if I majored veterinary medicine.

Additionally, I wanted to help others or protect my country since little kid. Majoring veterinary medicine and helping animals looks meaningful to me. So I had many thinkings about helping them directly by becoming a veterinarian. Even though I donate to animal protection group every month, I always wanted to help other animals when I saw them. People help people a lot, but animals don’t so I want to help them more.

Before now I was proud of my country and my country developed a lot. Now however to my view my country has a lot of concerns. Composition of population is an inverted pyramid and birth of rate is bottomed out and real estate price soared a lot. People are still fighting each other than pursuing benefit of country. So my country does not have bright future. This gloomy side of country lowers my passion about contributing to country. I hope this is my wrong thinking and hope my country to become a proud country again.

In conclusion, important things in my life are my family and people around me and helping others. With that things IT was suit to me.

Then Now?

So is that mean I don’t like what I do now?! No! That is not! I just reminded what is important things in my life. Still IT field is most suitable to me. A lot of interest in veterinary medicine has been added, but this IT is still interesting. There are new interests like animals, veterinary medicine and stocks but still IT is fun to me. I can say… it’s less than before, but I still like it.

So from now on I plan to study and do more things about animals with computer study. Although it’s hard to study veterinary medicine again… I’m considering the way to help in another way using my knowledge. There are voluntary work, donation, developing service and etc. There are many ways to help them.

I plan to study other many things, stock and also my work too.

The most important thing is to spend time with my family and people around me.

I didn’t intend it but it looks like my life retrospective. I think it is because this field and my life is connected strongly so retrospective carried out like above.

As a Blogger

Until Now

I’m proud that many people are watching and leaving questions. This blog is for me but it is always welcomed that people visit my blog. Good!

Last Year Goals

Last year goals are like below. There are two retrospectives [Retrospective](EN) Fourth-year tech blogger’s blog operation retrospective and [Retrospective](EN) Short retrospective in February 2021.

• Focus on contents
• Use capital letter when mentioning computer language if it does not have to written in lower case.
• If problems were found in existing documents, fix when problems were found. Don’t try to fix such problems in all documents
• Contents are important than layout and format
• Add professional contents
• Keep the way of writing as usual

I think I achieved goals except “Add professional contents”. I focused on writing contents well.

To give you an excuse about “Add professional contents” I didn’t have much time. With spending time with my family, stock, blog, meeting others I spend much time on studying new things than professional contents. In other words, I can say that I wrote helpful posts 3~4 more than watching professional one.

I think “Use capital letter when mentioning computer language if it does not have to written in lower case.” is not needed… Why did I write that?!

Now and Now On

Blog is still fun to me and one of the best services that I made. Posting is fun and communicating with visitors is also fun. It can be used as portfolio of me. Writing about what I studied or what I learned which is not related to company in daily life is meaningful and fun.

It can be changed in future, but this year and future goal is like below.

• Post about what I’d like to write

I would better write what I learned from daily life rather than a goal like writing about professional post like now.

As a Worker

Joining The Dream Company

I have used my company’s products since I was little kid and entered the company that I dreamed of. As I wrote before, I thought here was the right place where I can improve myself and earn experience of global work in my field. Even now, this company is the most closest to my goal. Now it has been five years since I worked for a company.

It is nervous to say… I entered the company what I wanted but I don’t think I feel the same way as before. I cannot say all about company because it is public blog. I have mind to move to another company if I can improve myself more and learn more.

In conclusion, I entered the company what I wanted since elementary school and it has been five years since I worked for a company and I had achieved my dream until I joined the company. Currently I am somewhat satisfied but I’m also open to work.

Current Company

I have something to say but it is a bit careful to say because this post is open to public. Overall my workplace is not bad. However I cannot settle here and need to find way. There seems to be a limit to focusing only on company work.

Career Path

My career has been a little different than I thought. First I wanted to work on cloud computing but about a year and half worked on cloud and one year for logging and other one year for data ingestion. It’s been five years in count years but exactly I’ve been working for three years and seven months.

I’d like to concentrate on one thing in deep but I couldn’t. It would be much helpful when do one thing deeply.

However good thing is that I will do same work what I did in last year so it would be helpful to my career path.

What I’d like to do are still cloud, platform and data. I think I’ve done similar things.

Still have concerns about my career path. However I’d like to do data ingestion more in about two years.

And So On

As I wrote, I have concerns about my career path. I am worried about the future because I have experienced changes in my work from time to time. However I’m still finding the way to solve that concerns. I’m studying cloud, platform and data by myself. I cannot leave my life to company.

Apart from career path, workplace life expectancy conservatively seems to be end in mid 40’s(It is around me. Not an official statistics.) in Korea. Nowadays, life expectancy is 100 so I’m worried about my future life. This is why I wonder if I should have done a specialized job like doctor even if I studied more. I think I should plan my concrete retirement plan after 40’s.

Concern

In about 20 years, there may be situations that I retire. Because life expectancy is getting longer but workplace life expectancy is still short. This is concern of mine. Whatever, I need to find the way!

Meaning of Job

Workplace is not a place where I can do only what I want. Honestly company and me are in a contract. Company hired me for their needs and I entered to do what they want me to do. It is a contract.

Sure here can be a misunderstanding. Raise one’s opinion freely and do work what employee want is really important in company’s work performance and productivity. I’m not talking about we must follow company because we are hired by contract. What I’m saying is that it is not easy to do what I want and satisfy in company. So in my opinion, I think we need coordination between myself and company.

Think how I can earn what I want in my company while doing what company want me to do. If that coordination is good it is perfect. If it is worse then it needs to be changed like transferring to other company or other team.

I think we should find our own way while follow company’s work. Inversely to achieve what I want in my life we constantly think how to use company that hired us.

We can use the company as a tool for my goal even though it is a contractual relationship.

Wrap Up

Contrary to my intention, my life retrospective is mixed a little.

If assume 100 is human life expectancy, I have lived 1/3 of my life. If assume mid 40 is workplace life expectancy, I have worked 1/4 of it. Blog is whole life job and IT field also has no ends in my life so I’m not considering when it ends.

I remind what is important in my life and think of how to spend my rest of my life during writing this post.

As I live to the age of 30, I think chances often come. Those chances can be many types like exams, stocks, bitcoin, relationships, real estate, companies and etc. I think I also had many chances around me and me(I took some of those chances and some of not). There must be another chances in the future. I need to prepare every time to take that chance.

I don’t know if I’ll have time to write retrospective again but I’ll cheer for my life!

쉘 스크립트(bash)에서 대문자 소문자 간 변환하는 방법에 대한 정리

환경

• Shell Script
• Bash

변환

대문자 -> 소문자

• POSIX standard

test="THIS is TeSt"
echo "$test" | tr '[:upper:]' '[:lower:]'

• Bash over 4.0

test="THIS is TeSt"
echo "${test,,}"

소문자 -> 대문자

• POSIX standard

test="THIS is TeSt"
echo "$test" | tr '[:lower:]' '[:upper:]'

• Bash over 4.0

test="THIS is TeSt"
echo "${test^^}"

참고자료

• https://www.cyberciti.biz/faq/linux-unix-shell-programming-converting-lowercase-uppercase/
• https://stackoverflow.com/questions/2264428/how-to-convert-a-string-to-lower-case-in-bash

Post about converting between upper case letter and lower case letter in shell script(bash)

Environment and Prerequisite

• Shell Script
• Bash

Convert

Upper case -> Lower case

• POSIX standard

test="THIS is TeSt"
echo "$test" | tr '[:upper:]' '[:lower:]'

• Bash over 4.0

test="THIS is TeSt"
echo "${test,,}"

Lower case -> Upper case

• POSIX standard

test="THIS is TeSt"
echo "$test" | tr '[:lower:]' '[:upper:]'

• Bash over 4.0

test="THIS is TeSt"
echo "${test^^}"

Reference

• https://www.cyberciti.biz/faq/linux-unix-shell-programming-converting-lowercase-uppercase/
• https://stackoverflow.com/questions/2264428/how-to-convert-a-string-to-lower-case-in-bash

PostgreSQL에서 테이블의 행(Row) 개수와 테이블 크기(Size) 구해보자

환경

• PostgreSQL

행(Row) 개수

• 쿼리에서 COUNT(*)를 이용

select count(*) from {table_name};

• pg_class를 통해 어림잡은 값 가져오기

select relname, reltuples from pg_class where relname='{table_name}';

select n.nspname as table_schema, c.relname as table_name, c.reltuples as rows
from pg_class c join pg_namespace n on n.oid = c.relnamespace
where c.relname='{table_name}' and c.relkind = 'r' and n.nspname not in ('information_schema','pg_catalog')
order by c.reltuples desc;

크기(Size)

• pg_total_relation_size() 함수를 이용

select pg_size_pretty(pg_total_relation_size('{table_name}'));

하나의 쿼리로 행(Row) 개수와 크기(Size) 구하기

create or replace function count_rows_of_table(table_schema text, table_name text)
returns numeric
language plpgsql
as
$$
declare
 count numeric;
begin
 execute format('select count(*) from %s.%s', table_schema, table_name)
 into count;
 return count;
end;
$$;

select n.nspname as table_schema, c.relname as table_name, c.reltuples as estimated_row_count, count_rows_of_table(n.nspname, c.relname) as exact_row_count
from pg_class c join pg_namespace n on n.oid = c.relnamespace
where c.relkind = 'r' and n.nspname not in ('information_schema','pg_catalog')
order by c.reltuples desc;

참고자료

• https://www.postgresql.org/docs/current/row-estimation-examples.html
• https://stackoverflow.com/questions/7943233/fast-way-to-discover-the-row-count-of-a-table-in-postgresql
• https://dataedo.com/kb/query/postgresql/list-of-tables-by-the-number-of-rows

Get table’s row count and size in PostgreSQL

Environment and Prerequisite

• PostgreSQL

Row Count

• Use COUNT(*) in query

select count(*) from {table_name};

• Get estimated value using pg_class

select relname, reltuples from pg_class where relname='{table_name}';

select n.nspname as table_schema, c.relname as table_name, c.reltuples as rows
from pg_class c join pg_namespace n on n.oid = c.relnamespace
where c.relname='{table_name}' and c.relkind = 'r' and n.nspname not in ('information_schema','pg_catalog')
order by c.reltuples desc;

Size

• Use pg_total_relation_size() function

select pg_size_pretty(pg_total_relation_size('{table_name}'));

Get row count and size using one query

create or replace function count_rows_of_table(table_schema text, table_name text)
returns numeric
language plpgsql
as
$$
declare
 count numeric;
begin
 execute format('select count(*) from %s.%s', table_schema, table_name)
 into count;
 return count;
end;
$$;

select n.nspname as table_schema, c.relname as table_name, c.reltuples as estimated_row_count, count_rows_of_table(n.nspname, c.relname) as exact_row_count
from pg_class c join pg_namespace n on n.oid = c.relnamespace
where c.relkind = 'r' and n.nspname not in ('information_schema','pg_catalog')
order by c.reltuples desc;

Reference

• https://www.postgresql.org/docs/current/row-estimation-examples.html
• https://stackoverflow.com/questions/7943233/fast-way-to-discover-the-row-count-of-a-table-in-postgresql
• https://dataedo.com/kb/query/postgresql/list-of-tables-by-the-number-of-rows