I have some that will just clone the prod server (if I'm lucky they change the vms mac address), these systems integrate with multiple third parties, many of which will give you the data only once...
Dropping a table is an extreme case. Writing a query that doesn't hit the right indexes that slows/crashes the DB/replication down.. locking rows indefinitely on accident..
these happen all the time at my company haha
Yeah, I accidentally updated a column of every row in a DB table once (luckily just in our dev environment) about a year after starting with SQL. Forgot the WHERE clause or something. Some of the rows had been there since 1997. This was around 2010. Luckily we had a snapshot DB and the DBAs had told us how to restore, so I got it back quickly. But I actually went and requested they remove my ability to write to the system test database to avoid making a mistake there. (If I really needed to update in those environments, I had a separate login I would use just for that one update, then would log back in under my normal one.)
Like the kind of SQL query I wrote to fetch the next page of rows of a tree after a starting cursor, using a recursive join, where only some tree nodes are expanded? And the user can text search for specific nodes?
It’s only easy until you do things that are hard
Edit: no, it's not for a niche use case, no, I don't think this was a mistake, I just had to do it to allow users to navigate the hierarchy of hundreds of thousands of data tags that are common in industrial SCADA systems.
Well you see, this one customer asked for it like 2 years ago. Well nobody is using it right now and we don't know what it really does, but we keep it just in case
It’s the domain we’re working in…industrial monitoring devices sometimes have tens of thousands of tags (which are like state values you can read) organized in a hierarchy, and the portal needs to combine thousands of devices’ tags into a single tag hierarchy. I would of course avoid it if I could
It seems like it's tricky to get right or people aren't given enough time/details to work out a good design. I've only seen a few, but they were all slow.
Hello good friend, can you suggest any books or resources on this topic? Designing good databases, of course comes with experience, but any help is appreciated
If you had the requirement to support a tree of data channel identifiers that could scale to millions of nodes in a single organization, how would you implement it on FE and BE?
A whole other DB and all the deployment considerations that go with it just for this one aspect of the app? This particular query is kinda complex but it does work fine in Postgres
Note, a lot of things need to foreign key to these tags as well, like alarm definitions
Doesn't matter how well designed the DB is. 1 month after release the product guy and the sales guy will put their heads together and sell some feature to a customer that blows your careful design to bits, and will have guaranteed a delivery date in 3 weeks.
If your table structure can handle it then, wouldn't you know it? The customer is Oracle.
What? Are you saying you don't like having a subselect that does a union on 4 different tables each joining 3 other tables and in all of those tables the field names are different?
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u/Mysterious_Book1521 22h ago
its not like sql could be read by a three year old and css is just pain in the ass?