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Paul White

00:03

@CadeRoux For two statements that are logically equivalent yes the percentage accurately conveys the difference in optimiser estimated costs. It's pretty useless beyond determining why the optimiser chose one candidate plan over another. Best ignored in general. I wouldn't be sad to see it removed one day

Anything based on estimates can be wrong

Also there are many assumptions built in for example that every query starts with a cold cache and your hardware is 30 years old

2 hours later…

Cade Roux

01:55

Even when you turn on show actual plan and run the queries, it's just based on the estimated plan?

4 hours later…

John K. N.

06:04

Morning

@PaulWhite ...and a simple desktop computer at that.

Paul White

06:33

@CadeRoux the percentages? yes. that element really is a hangover from the very earliest days. there's much better information in modern showplan now

McNets

06:58

Morning

Tom V

Morning

@CadeRoux Yes the actual plan just adds the actual number of rows and such next to the estimated rows

2 hours later…

Vérace

08:47

A chairde - Morning all!

Myself and @AndriyM have both answered this question. I did a quick performance analysis on both our solutions - I wonder wouild any of the SQL guys here care to give a quick compare and contrast... see bottom of fiddle.

If you're going to upvote anyone, it should be Andriy (see the chat here) - he cracked it really, so kudos to him!

It's the meaning of Rows vs. Executes and Logical reads - I have 67 Logical reads, Andriy has 0 - don't understand why?

ypercubeᵀᴹ

09:33

@Vérace maybe because your query has a recursive CTE

Colin 't Hart

I presume most (all?) DBMSes execute a recursive CTE row-by-row, unrolling it.

So it's a form of row-by-row processing, I think?

Paul White

10:03

Meanwhile the entire network is down

Aside from chat ofc

Vérace

Yep - I was wondering!

Can get my news sites - but no dba.se! 😢

Paul White

The recursive CTE reports logical reads from the worktable used to store stacked rows (the index spool and table spool are the same object under the covers)

status.fastly.com

> Update - We are continuing to investigate this issue.
Jun 8, 10:07 UTC
Investigating - We're currently investigating potential impact to performance with our CDN services.
Jun 8, 09:58 UTC

Potential impact to performance LOL

Everything is broken

Vérace

Dublin is not working!

Paul White

Companies are awful about reporting status, without exception
Like if they play it down it won't be as bad as it is

It also says Auckland is operational and all green

> Fastly error: unknown domain: dba.stackexchange.com.
Details: cache-akl10322-AKL

That would not be operational

> Fastly’s network has built-in redundancies and automatic failover routing to ensure optimal performance and uptime. But when a network issue does arise, we think our customers deserve clear, transparent communication so they can maintain trust in our service and our team.

ho ho ho

ypercubeᵀᴹ

10:34

@PaulWhite it now says Degraded Performance

Paul White

@ypercubeᵀᴹ Yes it took a good long while to update

ypercubeᵀᴹ

gov.uk is also down

bbc.co.uk/news/technology-57399628

www.gov.uk : connection failure

John K. N.

CNN

> Error 503 Service Unavailable
> Service Unavailable
>
> Guru Mediation:
>
> Details: cache-wdc5534-WDC 1623148211 942212905
>
> Varnish cache server

They ran out of varnish

Paul White

It vanished

John K. N.

:-)

Paul White

10:45

I see the updates on the fastly status page have stopped as well

Ooo! As I type that it updates:

> Identified - The issue has been identified and a fix is being implemented.
Jun 8, 10:44 UTC

John K. N.

Sorry my fault.

While I was on the internet I clicked on File | Save as ....

Paul White

Site is back up

John K. N.

downdetector.com

> Reports indicate there may be a widespread outage at Fastly, which may be impacting your service.

ahem

Paul White

11:17

hm might be down again

oh that's SO switching back to CDN

back

ish

Vérace

11:40

Dublin is back up - rest of world no longer cut off! :-)

Paul White

11:52

chat broke for about ten minutes for me

static assets have started loading at last

John K. N.

12:10

ping

working

Paul White

-1

A: Foreign Key with a Constant

Using a CHECK constraint : CREATE TABLE Test1 ( ThingA INT NOT NULL, ThingB INT NOT NULL, PRIMARY KEY (ThingA, ThingB) ); INSERT INTO Test1 VALUES (1,1),(2,1),(3,2); CREATE TABLE Test2 ( ThingA INT NOT NULL, ThingB INT NOT NULL DEFAULT(1) CHECK(ThingB = 1), Val INT NOT N...

Struggling to think of worse way to answer this old question

1 hour later…

Paul White

13:33

The quality of the questions this morning are making me wish we'd stayed offline a little longer

ypercubeᵀᴹ

13:45

They edited the FK-with-constant answer.

Slight improvement I'd say. Not that it has much future when it suggests a CHECK with a function

Paul White

yeah I saw

aside from the usual issues...checking the entire fk relationship on every change...

remarkable

I'm tempted to flag it as offensive 😀

ypercubeᵀᴹ

ah, the COUNT, yeah

There is so much code out there that it inefficient.

Paul White

It's amazing anything works

ypercubeᵀᴹ

Whoever thought that "premature optimization is the root of all evil" applies to Databases should have his tweeter removed. Like Trump

Paul White

heh heh heh

@ypercubeᵀᴹ can you imagine loading a million rows into that table one at a time

because someone would try it and ask about the performance

ypercubeᵀᴹ

13:54

Of course they would only ask after it was fully in production ;)

Paul White

Is O(LOL) official big-O notation?

there is something like that I think

Maybe O(MG)

ypercubeᵀᴹ

> I thought it was a great solution :) Thanks for pointing out my mistake.

Everyone thinks that, the first time they consider a function in CHECK ;)

Paul White

Yes like they've solved one of science's great problems

Vérace

14:13

@PaulWhite > the quality of the questions this morning are making me wish we'd stayed offline a little longer

:-)

John K. N.

14:35

-5

Q: Can I use images such as from Tiananmen Square Protests to criticise the Chinese government on my profile page?

Dear Stack Exchange Community, As many of you know, for I long time I have been allowed to show images that criticise the Chinese government on my profile for several years, for which I'm thankful. Furthermore, I believed that this had strong meta support in threads such as: User's political dis...

Yes, I am concerned about Chinese politics too. No, Stack Exchange is not a billboard and your profile is no exception. — Glorfindel 2 days ago

I quite like that summary.

Paul White

I don't read comments

ypercubeᵀᴹ

15:24

@JohnK.N. is this Evan's cousin from China? ;)

mustaccio

16:01

@ypercubeᵀᴹ From Brazil. Social justice warriors often live quite far from those who they fight.

user2639

@ypercubeᵀᴹ No, absolutely not. =) And his rhetoric is ridiculous (imho), and I don't agree with the goal of getting the site banned from China.

However, I am cool with him using his own nickname on his obviously valuable contributions to bring attention to serious human rights issues.

So if you're looking for one guy to point to that would make me "moderate" I guess you found him. ;) But I've known about him for a while.

If you ever have time though to read Ciro's home page, I highly suggest it.

2 hours later…

ypercubeᵀᴹ

17:46

not a fan of the horror genre, thank you

3 hours later…

Philᵀᴹ

20:38

How is everyone today?

swasheck

alive

Cade Roux

21:06

Morning

billinkc

I have been blessed to return to the office twice a week starting this week and wow, I am so much more productive there what with the open office concept, chatty coworkers in other rooms, two rinky dink monitors, an inferior chair. What's not to love

twitter.com/CarmenCrincoli/status/1397996630326927364

Tweet is an encapsulation of how the sales pitch went before it was escalated to mandatory

Philᵀᴹ

@billinkc lol

No office for me ever again

Had loads of linkedin recruiters come back to me a few weeks after I told them to get lost. "Oh, the role is now fully remote, had to change it"

Lamak

@billinkc we have free choice over here...

I do like going to the office sometimes though. Mainly because in my apartment I don't really have a desk or anything like that

billinkc

The argument for being in the office is that we just don't have the collaboration between business owners and developers that they (business) want. We have these online meetings that take longer and people come out with different understanding of what we're doing.

Except this past year has been the only time the owners have ever had to commit in writing what they want done...

@Lamak How's your Ma, family and you doing working through grief and such?

Lamak

21:23

@billinkc eh, so so. Though my mother seems to be doing quite well taking everything into account

Philᵀᴹ

@billinkc I've found online meetings more focussed

billinkc

Good to hear and believe me, I get some of where you're coming from.

dignitymemorial.com/obituaries/kansas-city-mo/…

Philᵀᴹ

@billinkc <3

Covid took my grandma

billinkc

@Philᵀᴹ Ours are still pretty scattered but we actually write down what was discussed and what we think is going to happen.

Philᵀᴹ

It's been a rough one all round

Lamak

21:29

@billinkc oh man, I'm sorry

hugs for you dude

billinkc

@Philᵀᴹ This was just a heart attack and he went quickly but yeah...

Lamak

@Philᵀᴹ jeez, I'm sorry....hugs for you too

Philᵀᴹ

It's alright. Doesn't in any way take away from the pain yourself and others are going through, or have done as a result of this pandemic or otherwise

We're all human ;)

Except Evan, obviously. He's an alien

This place is still the best gymnastics group that anyone could ask for

Lamak

@Philᵀᴹ don't forget @billinkc