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Today’s Top Tech Skills

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Re: Today’s Top Tech Skills

#201

Post by andybak »

dathinab wrote: post #25

In the recent two or so years I was surprised to see how many people don't _really_ know about SQL. Sure they can write a simple insert and update query and maybe a join, assuming they can just ignore that there actually are different types of joins. But if you ask them about other _still fundamental_ knowledge like a _rough_ idea about what the different transaction isolation level are/mean/imply for you, they fail…

> which make it in practice harder to access the database for anything but trivial queries.

I did my time. I understand normalization. I've got a vague understanding of the various normal forms (except 6NF which nobody seems to understand ;-)

I can use a query profiler and I've occasionally read up on the different index types and their performance profiles.

But I still prefer to use an ORM. SQL syntax just never fitted my brain.

And the ORM I use can handle aggregation, annotation and a bunch of stuff that you couldn't really describe as "trivial queries"

Re: Today’s Top Tech Skills

#202

Post by [deleted] »

pmoriarty wrote: post #199
dathinab wrote: post #25

In the recent two or so years I was surprised to see how many people don't _really_ know about SQL. Sure they can write a simple insert and update query and maybe a join, assuming they can just ignore that there actually are different types of joins. But if you ask them about other _still fundamental_ knowledge like a _rough_ idea about what the different transaction isolation level are/mean/imply for you, they fail…

I really don't get all the hoopla about learning SQL. There's really not much to it. It can be learned in an afternoon. It's by far the easiest language I've ever learned. To all the naysayers and downvoters: There's a difference between knowing SQL and being an SQL ninja or a master of database architecture. Those are three different things. The former, and what my original comment concerned, was just learning the l…

[deleted]

Re: Today’s Top Tech Skills

#203

Post by SkyPuncher »

tooop wrote: post #72
phit_ wrote: post #2

the lack of PHP is surprising to me, but I guess there isn't that many PHP full time roles to fill?

Either it is specific to USA or the data is weird, https://www.codingdojo.com/blog/the-7-most-in-demand-program... reports that in January (based on the same Indeed.com site) PHP is behind C#. PHP is powering >75% websites it just makes no sense to not even be in the Top20

It's because the complexity of those sites is low. My understanding is a large portion of that 75% is Wordpress sites. A very, very small portion of Wordpress sites do much development past a theme (many CSS/HTML) and installing some plugins.

If you have extensive Wordpress work, it's likely better to use a different starting point (and a different language).

Re: Today’s Top Tech Skills

#204

Post by vsareto »

pmoriarty wrote: post #199
dathinab wrote: post #25

In the recent two or so years I was surprised to see how many people don't _really_ know about SQL. Sure they can write a simple insert and update query and maybe a join, assuming they can just ignore that there actually are different types of joins. But if you ask them about other _still fundamental_ knowledge like a _rough_ idea about what the different transaction isolation level are/mean/imply for you, they fail…

I really don't get all the hoopla about learning SQL. There's really not much to it. It can be learned in an afternoon. It's by far the easiest language I've ever learned. To all the naysayers and downvoters: There's a difference between knowing SQL and being an SQL ninja or a master of database architecture. Those are three different things. The former, and what my original comment concerned, was just learning the l…

The finer points probably require a bit more than that.

If you're already technically proficient in general programming (or Excel), you're likely to pick up SQL quickly.

There is immense, unwarranted filtering of people from jobs for relatively minor things.

Re: Today’s Top Tech Skills

#205

Post by AlphaSite »

pmoriarty wrote: post #199
dathinab wrote: post #25

In the recent two or so years I was surprised to see how many people don't _really_ know about SQL. Sure they can write a simple insert and update query and maybe a join, assuming they can just ignore that there actually are different types of joins. But if you ask them about other _still fundamental_ knowledge like a _rough_ idea about what the different transaction isolation level are/mean/imply for you, they fail…

I really don't get all the hoopla about learning SQL. There's really not much to it. It can be learned in an afternoon. It's by far the easiest language I've ever learned. To all the naysayers and downvoters: There's a difference between knowing SQL and being an SQL ninja or a master of database architecture. Those are three different things. The former, and what my original comment concerned, was just learning the l…

Basic SQL sure, but the moment you start getting into complex operations, upserts, extensions, functions, custom aggregate operators, arrays, HStores, etc it gets complicated. At least for me.

I would not be able to do this super quickly: https://stackoverflow.com/a/42939280

Re: Today’s Top Tech Skills

#206

Post by andybak »

geophile wrote: post #197
daxfohl wrote: post #174

Earlier quoted context omitted.

Blech, the worst thing I've noticed after moving to document databases even when scale does matter is the loss of the relational data model. A nice ERD that shows relationships between your entities makes everything so simple. You could have one for document database as well but people stare at you strangely. So now it's just a random collection of collections of stuff, and it takes 10x more words to describe your de…

This is a really good read: http://www.sarahmei.com/blog/2013/11/11/why-you-should-never... It shows what happens when you have exactly the misunderstandings being discussed here. Also note that the author still has absolutely no idea how to do a simple ER diagaram.

My favourite line:

> Once we figured out that we had accidentally chosen a cache for our database, what did we do about it?

I'm going to use that one to win imaginary arguments in my head with my pet NoSQL strawman.

Re: Today’s Top Tech Skills

#207

Post by gdy »

davidjnelson wrote: post #178
itronitron wrote: post #99

Earlier quoted context omitted.

>> many people don't know anything about the browser rendering pipeline if you can recommend a good source for learning the browser rendering pipeline please post it here, everyone I have asked just shrugs it off and says that no one really knows.

This one is quite good. I posted it to Hn 6 years or so ago but it didn’t get upvotes: https://www.html5rocks.com/en/tutorials/internals/howbrowser...

How much of it is relevant 8 years later?

Re: Today’s Top Tech Skills

#208

Post by brightball »

dadoge wrote: post #102
brightball wrote: post #42

Earlier quoted context omitted.

My go to interview question to test basic SQL knowledge is use of “HAVING”. It’s a surprisingly good filter. EDIT: To clarify since this got more attention than I expected...I don’t disqualify any candidate based on the answer to a single question. I just use that question to assess their actual SQL experience. If you’ve spent any amount time writing raw queries by hand for reports or just to pass through to a web se…

Is the pun of saying knowing “HAVING” is a good filter intended?

It is now.

Re: Today’s Top Tech Skills

#209

Post by freedomben »

FpUser wrote: post #91
brightball wrote: post #42

Earlier quoted context omitted.

My go to interview question to test basic SQL knowledge is use of “HAVING”. It’s a surprisingly good filter. EDIT: To clarify since this got more attention than I expected...I don’t disqualify any candidate based on the answer to a single question. I just use that question to assess their actual SQL experience. If you’ve spent any amount time writing raw queries by hand for reports or just to pass through to a web se…

My use of SQL beyond very basic is very sporadic (I do remember about HAVING though). If you ask me out of blue I would most likely fail tests. From time to time however I do have to design database for particular product and in a matter of few days my knowledge gets from basic to very good one. Only to go down again a short while after database design implementation and testing completes. That does not mean that I d…

Exactly. You don't use it, you lose it. That doesn't mean you don't have the capacity to reacquire it in a short period should you need it again. Most humans are not encyclopedias.

I can describe for you in detail the different index types on MySQL and Postgres, and go into when/why you would use each. But it's been so long since I crafted a complex join by hand I would definitely have to google it. However I don't doubt that I could write the query in a short time. One of the most realistic interviews I ever had, they gave me a laptop and allowed me to google during my answer. I took the job.

Re: Today’s Top Tech Skills

#210

Post by babuskov »

SkyPuncher wrote: post #196
kradroy wrote: post #95

Earlier quoted context omitted.

Eh, HAVING is something that can be learned in 5 minutes. So filtering out for that is probably generating a lot of false negatives. I quiz them on indexes and table design. Those can be done without writing a single SQL query.

I look up HAVING every time I write it. I just don't use it enough to keep it in memory as a first class concept. A quick google search with an example is enough to jog my memory. If I got asked about it on an interview, I'd be completely blank.

I'm curious now. What's there to look up? It's just like WHERE, but you use it on aggregate values.

WHERE filters the data before you aggregate it, HAVING afterwards.

That's all there is to it.

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