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Comment Re:1PB meh (Score 1) 150

> So I would leave the write master in the backend and all the POS would have the inventory pretty much in real time on their local read node.

That's pretty much it. So the front end is instant response for the user. Events are timestamped. The back end recombines the data in order when they are attached (normally they are attached all the time) and the inventories are kept in sync. The wrinkle is that the front end stores running state to local disk as pickled data so it can run solo (detached from the back end) across power cycles. Works great for trade shows - you can run it on a laptop.

I can bring down the back end, upgrade the the OS, have a coffee, watch some Netflix and bring it back up again an no one notices.

Comment Re: 1PB meh (Score 1) 150

Please tell me you are kidding, because if you are not you need to step away from the keyboard, and STAY away from the keyboard.

No, not kidding. Now please explain how you know enough about our system to even be able to know if it's a good idea or not?

The draw to tell people on the internet that they're doing it wrong seems to be very, very strong around here, even when armed with only a couple of paragraphs of information.

Comment Re:1PB meh (Score 1) 150

>So.. going to write your own reporting solution as well?
I already have. The reporting code doesn't change to accommodate this. The interface to the data model doesn't change. You have heard of data abstraction before haven't you? If you mess with stored procedures, you're still tied to the nipple of a DB vendor's tit. If the business logic code access the DB through your own procedures written in in-application code, then it's easy to adjust to a different storage model.

>Or does management not need any reports?
Well we own the company and so I write exactly the reports that we need. The accountant gets the transaction data in exactly the form they need to automatically reconcile with bank records. Apparently all her clients with the quickbooks tools can't do that.

>Any guidelines from regulators viz. your storage and ability to audit the data?
Nope. Personal data isn't in the PoS (point of sale) system. Financial transaction stuff (credit card info, etc.) is in PCI-DSS compliant kit. That doesn't change. The PoS is about an efficient storefront (checking out purchases) and inventory management.

>Most modern RDBMS do have in-memory tables. SQL Server 2016 has them
That's lovely, but I don't need an RDBMS. The properties of time series data (people buying things) allows a nice post hoc recombination at the back end and allows the front end (at checkouts) to carry on regardless if they lose contact with the back end, so no "The computers have gone down, we can't sell you this". It is all already in tables, then synced to the database on the server. The actual design change is to store transactions locally on disk - it's only a handful of bytes per transaction - in such a way that you can pull the plug and reboot the front end and have it carry on from the point it was switched off including the contents of the current transaction that was being input. This is not a hard problem, it just requires knowledge of designing sound transactions (in the computer sense) and you can formally prove they are right with tools like spin. I can't even start python database connector without a bunch of hacking on the platform.

> It even runs on Linux nowadays
So does the existing PoS software, which I wrote and the staff like because I iterated the design with them in the loop. It exists explicitly because off the shelf solutions were slow and cumbersome.

>All in all I think if the application was critical, I'd take out a license for an off-the-shelf database that does this already.
It is. It's the conduit through which we sell things. But it is based on a well polished bit of software that essentially bug free and keeps running year after year. I wouldn't risk commercially licensed software. What happens when it breaks, or it requires and os upgrade or it just goes out of fashion?

However the substance of my comment was to agree with the comment before which suggests that large data tools are no applicable to most situations and I have a situation that fits that hypothesis, where the transaction rate is 10s of thousands per years. There are no Petas involved. I wasn't requesting a lecture on how to run our business.

Don't apply for the job of DB admin, we aren't hiring.

Comment Re:Two glasses of wine per day would wreck me (Score 1) 123

1 glass of wine doesn't even use up your quiescent ADH levels. It is quickly metabolized. The third and fourth glasses are past the point that the metabolization rate is determined by the production rate of ADH and so stays around a lot longer.

Does this apply to those who turn red after drinking even a 1/2 glass of wine as well???

Asian glow? I suspect not, but I've never read a peer reviewed paper that addresses the issue, so I would be spouting bullshit if I claimed to know. I suspect not because that is caused by a lack of an enzyme to process a breakdown product and I've forgotten all the names and I'm not looking it up right now.

Actually, that's probably what OP was referring to: ADH - Alcohol dehydrogenase

That's what I'm thinking too, but I don't actually know. I'd have to go an read up on it. Where's a biochemist when you need one?

Comment Re:Wonder why (Score 1) 207

>1: HOAs. Even with a decent HOA, you are still spending hundreds of dollars of month, with the HOA assessment being raised 10% every year for nothing. Of course, there are the neighbors with no life just looking for any small violation to call in.

I am the treasurer of a HOA. I am the one who proposes rate increases when necessary.

Rate increases for nothing might happen in some HOAs but my assertions is that for most HOAs, nobody is paying any attention to the finances.
The major costs are:

1) Reserves. By law there is a reserve study that predicts future infrastructure spending. You must fund this intelligently or face special assessments. The reserve study might be complete bullshit. Find out. Understand the lifetime and maintenance schedules for your common areas. Don't just spend because the reserve study says to do so. Your management company might try to anyway. Stop them and hold them to account.

2) Management company fees. This is rent seeking behavior. On the West coast I have noticed that most HOA management companies are run by Mormons. They are very good and organized at rent seeking behavior. Seek out more efficient ways. Management companies should be able to be replaced by a decent web service and a lawyer and accountant on retainer and that should be something like an insurance service you can sign up for. It's massively overpriced as it is.

3) Insurance. Common area insurance is ludicrous. They charge what they can get away with. This has been the cause of most cost increases in recent years as the insurance industry colludes to raise prices together. I don't know why the feds haven't cracked down on this. If you can't afford your common areas, get the homeowners to agree to have them removed or paved over.

Every year I present graphs of the bank accounts and the present and predicted reserve spending and normal spending and show how close to going negative (I.E. needing a special assessment) we are. I ask the homeowners to make choices about spending (Do you want pretty hanging baskets? That's $3/house/month on the fees). I ask them to vote to show consent to raises. I ensure they understand the consequences. They have never turned down an increase when they understood it was needed. The board gets clear direction on the spending the homeowners have agreed to. As it happens people want to spend on pretty hanging flower baskets.

If your treasurer is not doing these things, ask them why?

Comment Re:Holy Blinking Cursor, Batman! (Score 2) 235

Some tests make sense. Others are head-scratching. For UNIX admin jobs, I have been asked moving a database from first normal form to DK normal form, but in reality, I've yet to see any DBA go past 3NF unless it is some specialized data warehouse/data mart task.

It was 1st NF --> 2nd NF --> 3rd NF --> BC NF when I went to college. I'd never get past your interview. But then I don't want a DB job so it's all good.

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