ott Comments - Answer Overflow

ott

•Created by ott on 4/17/2025 in #general

Oh is it literally another db table? The

I didn't consider that every query needs to also be on the timestamp because of the optimistic CC, so it makes sense why a b+tree would perform better

6 replies

CCConvex Community

•Created by ott on 4/17/2025 in #general

Oh is it literally another db table? The

I did some rough IO estimates for the FIND document WHERE id = <id> AND timestamp <= t (please correct me if I got anything wrong). it looks like they have similar best case scenerios, but the LSM struggles when L0 is tiered. If it was leveled, I think the IO numbers could be pretty similar. key size: 64 bytes value size: 448 bytes entry size: 512 bytes OS page size: 4096 bytes 1 billion entries = 512 GB total storage query: read document/row at timestamp lsm (e.g. rocskdb): - size ratio (T) = 10 - L0 tiered, L1.. leveled - L0 = 10 MB - entries per page = 4096 bytes / 512 bytes = 16 - 1 MB skiplist as the memory buffer - bloom filters with 1% false positive rate - fence pointers on each level/SSTable

| Level |   size | num Entries | num SSTables |
| ----- | ------:| -----------:| ------------:|
| 0     |  10 MB |         20k |   1-10 (var) |
| 1     | 100 MB |        200k |           10 |
| 2     |   1 GB |          2m |          100 |
| 3     |  10 GB |         20m |           1k |
| 4     | 100 GB |        200m |          10k |
| 5     | 400 GB |        777m |          40k |

| Level |   size | num Entries | num SSTables |
| ----- | ------:| -----------:| ------------:|
| 0     |  10 MB |         20k |   1-10 (var) |
| 1     | 100 MB |        200k |           10 |
| 2     |   1 GB |          2m |          100 |
| 3     |  10 GB |         20m |           1k |
| 4     | 100 GB |        200m |          10k |
| 5     | 400 GB |        777m |          40k |

better case 1. search memory buffer(s): 0 IOs 2. L0 search: 1 IO = 1 IO worse case 1. search memory buffer(s): 0 IOs 2. L0: 10 IOs for each SSTable (they have overlapping key ranges) 3. L1-L5: 1 IO per level (non overlapping key ranges) = 5 IOs. fence pointer cached in memory = 15 IOs b+tree: - leaf nodes: 64 bytes (key) + 8 bytes (pointer) = 72 bytes - non-leaf nodes: 64 bytes + 8 bytes = 72 bytes - ~56 nodes / page - h = 5 better case: 1. all leaf nodes cached 2. 1 IO for value read = 1 IO worse case: 1. 5 IOs for index traversal 2. 1 IO for value read = 6 IOs

6 replies

CCConvex Community

•Created by ott on 4/17/2025 in #general

Oh is it literally another db table? The

thanks for answering my questions. I find this stuff super interesting and I'm currently doing database research at uni.

we want to be able to query a snapshot of the index at slightly stale timestamps. this then shifts the workload towards more range scans, which are (often) better on btrees.

for the LSM case, you could have a key of key;<MAX_TS - t> so that keys are sorted most recent first

user:42;990  ->  t=9
user:42;995  ->  t=4
user:42;999  ->  t=0

user:42;990  ->  t=9
user:42;995  ->  t=4
user:42;999  ->  t=0

6 replies

CCConvex Community

•Created by ott on 4/17/2025 in #general

Oh is it literally another db table? The

whats the reason for using relational databases instead of kv stores for the storage backend? if everything is a byte string, and the source of truth is a LOG, wouldn't using a LSM backed storage engine be more efficient than a b+tree backed one?

6 replies

TTCTheo's Typesafe Cult

•Created by ott on 2/7/2024 in #questions

Creating `AudioContext` in Next.js

There was someone else doing something similar with zustand and audio context in the server (search for AudioContext) which is where I got the idea for the setup on my store, but I want to know if there is a better way.

3 replies

TTCTheo's Typesafe Cult

•Created by Brycycle on 12/16/2023 in #questions

TypeError: GoogleProvider is not a function when running with .ts script using tsx

Does it need to be .tsx, afaik GoogleProvider is a react component

6 replies

TTCTheo's Typesafe Cult

•Created by ott on 10/17/2023 in #questions

OAuth providers on vercel preview deployments with NextAuth

I didn't end up trying, but if you go to the create t3 turbo monorepo, they have some app called auth-proxy that prob solves this issue

4 replies

TTCTheo's Typesafe Cult

•Created by Xaohs on 10/17/2023 in #questions

Render either a Sheet, or a Dialog in a streamlined way with Shadcn/ui?

fair enough

18 replies

TTCTheo's Typesafe Cult

•Created by Aidam on 10/17/2023 in #questions

React Native with T3

I used https://github.com/t3-oss/create-t3-turbo, but it took a lot of fiddling with to get pnpm with react native working

4 replies

TTCTheo's Typesafe Cult

•Created by Xaohs on 10/17/2023 in #questions

Render either a Sheet, or a Dialog in a streamlined way with Shadcn/ui?

why do you want to render a sheet anyway?

18 replies

TTCTheo's Typesafe Cult

•Created by Xaohs on 10/17/2023 in #questions

Render either a Sheet, or a Dialog in a streamlined way with Shadcn/ui?

i don't think its an antipattern, i've mostly just used the mobile dialogue because its works well enough

18 replies

TTCTheo's Typesafe Cult

•Created by Xaohs on 10/17/2023 in #questions

Render either a Sheet, or a Dialog in a streamlined way with Shadcn/ui?

something like K in keyof T if K not keyof U and K in keyof T if K keyof U, im not a major typescript expert but chatgpt might be

18 replies

TTCTheo's Typesafe Cult

•Created by Xaohs on 10/17/2023 in #questions

Render either a Sheet, or a Dialog in a streamlined way with Shadcn/ui?

https://nabeelvalley.co.za/blog/2022/08-07/common-object-type/

18 replies

TTCTheo's Typesafe Cult

•Created by Xaohs on 10/17/2023 in #questions

Render either a Sheet, or a Dialog in a streamlined way with Shadcn/ui?

ya, there probably a way to get the intersecting properties and unique properties so you can do something like <Sheet {...intersecting} {...sheetProps}> and <Dialogue {...intersecting} {...dialogueProps}>

18 replies

TTCTheo's Typesafe Cult

•Created by Xaohs on 10/17/2023 in #questions

Render either a Sheet, or a Dialog in a streamlined way with Shadcn/ui?

i would make a single component that renders both the dialogue and sheet like

export function DialogueOrSheet({trigger, title, description}) {

return (
  <>
  <Sheet className="block lg:hidden">
  <SheetTrigger>{trigger}</SheetTrigger>
  <SheetContent>
    <SheetHeader>
      <SheetTitle>{title}</SheetTitle>
      <SheetDescription>{description}</SheetDescription>
    </SheetHeader>
  </SheetContent>
</Sheet>
<Dialog className="hidden lg:block">
  <DialogTrigger>{trigger}</DialogTrigger>
  <DialogContent>
    <DialogHeader>
      <DialogTitle>{title}</DialogTitle>
      <DialogDescription>{description}</DialogDescription>
    </DialogHeader>
  </DialogContent>
</Dialog>
</>
)
}

export function DialogueOrSheet({trigger, title, description}) {

return (
  <>
  <Sheet className="block lg:hidden">
  <SheetTrigger>{trigger}</SheetTrigger>
  <SheetContent>
    <SheetHeader>
      <SheetTitle>{title}</SheetTitle>
      <SheetDescription>{description}</SheetDescription>
    </SheetHeader>
  </SheetContent>
</Sheet>
<Dialog className="hidden lg:block">
  <DialogTrigger>{trigger}</DialogTrigger>
  <DialogContent>
    <DialogHeader>
      <DialogTitle>{title}</DialogTitle>
      <DialogDescription>{description}</DialogDescription>
    </DialogHeader>
  </DialogContent>
</Dialog>
</>
)
}

18 replies

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