Is d1 suitable for web apps with say thousands of daily users? It feels complicated to setup multipl

Is d1 suitable for web apps with say thousands of daily users? It feels complicated to setup multiple d1s so I would prefer to just have like one for all users like a ”normal” database

Aamanzad Is d1 suitable for web apps with say thousands of daily users? It feels complica...

aza547•11/8/25, 1:35 PM

I'm using it for this, just keep in mind it's single threaded so there are limits to scalability. But I'm using replication and it's working great since enabling that for my few thousand users.

amanzadOP•11/8/25, 4:24 PM

Oh okay, could you point me to guides or docs on how to achieve this? Also how well does this structure handle many writes and limits of like 10gb storage or the 128mb memory limit?

blyedev•11/8/25, 7:45 PM

Hi I don't know if this is known but maybe someone from Cloudflare decides to push on this. Sadly because cloudflare uses PRAGMA defer_foreign_keys not the simple turn on or off the migrations generated by drizzle are invalid and often broken. This means if we want to use drizzle with cloudflare we need to hand edit migrations

Aamanzad Is d1 suitable for web apps with say thousands of daily users? It feels complica...

lambrospetrou•11/8/25, 8:17 PM

I am hoping to merge this docs update on Monday, and it contains some guidance on D1 performance: https://github.com/cloudflare/cloudflare-docs/pull/26369

If you have thousands of active users at the same time, which will translate to high hundreds or thousands of queries to D1 at the same time (e.g. per second), then you will hit performance limitations and overload the single database.
You will definitely need to shard across several databases.

If you are going to have many thousands of queries per second and would need tens of D1 DBs, then using SQLite Durable Objects would be preferable and my suggestion. You can create thousands of Durable Objects dynamically in your code without having to mess with bindings, and it's the same underlying SQLite engine.

tobystr•11/9/25, 4:33 AM

Before I test, how many rows per second can D1 / DO with SQL scan per second? any unofficial data around it?

Ttobystr Before I test, how many rows per second can D1 / DO with SQL scan per second? an...

lambrospetrou•11/9/25, 8:40 AM

I have seen high hundreds of thousands or single digit millions reads per second. Obviously it's different if your rows are 10 bytes vs 2MB!
Also, with such high number of reads per second, if you are doing that constantly you need to be careful of hitting CPU limits, or overload limits since a DO is single threaded.

Cemal•11/9/25, 9:19 AM

Hi, I have a question about D1. I'm using it together with Drizzle ORM. I have a table that stores user balances, and each request deducts from the balance. The issue is that a simple query like

amount -= 100

amount -= 100

might cause a problem known as a race condition (I think). It seems D1 doesn't support transactions, so could async operations cause issues here?

Larry•11/9/25, 10:29 AM

I have seen high hundreds of thousands or single digit millions reads per second.

Wait! How is that possible? I've been using no more 1,000 request/messages per second as design ceiling for DOs, eventhough, I've seen as high as 5,000. Even assuming 5,000, you'd need 200 read replicas to hit 1M. Does D1 go to that level?

tobystr•11/9/25, 12:16 PM

@Larry if think we are discussing different things, I was asking how many rows per second can be scanned, so if you have a table with 100k rows, how long would it take to scan it, vs request per second which would be how many queries can run in a second

Ttobystr @Larry if think we are discussing different things, I was asking how many rows p...

Larry•11/9/25, 12:21 PM

Duh, I should read more carefully. Thanks for the clarification! That makes a lot more sense.

tobystr•11/9/25, 12:22 PM

No problems

CCemal Hi, I have a question about D1. I'm using it together with Drizzle ORM. I have a...

Cemal•11/9/25, 2:47 PM

Would an atomic update be sufficient?

UPDATE account SET amount = amount - ? WHERE id = ?

UPDATE account SET amount = amount - ? WHERE id = ?

Or using durable objects.

CCemal Would an atomic update be sufficient? ```sql UPDATE account SET amount = amount ...

James•11/9/25, 5:56 PM

I like using DOs for transactions more simply because you control the thread of processing. Run a bunch of SQL in synchronous code with the right error handling in place and you have transactions.

Another approach I use when coordinating changes async across D1/DO other resources in a saga pattern.

blyedev•11/9/25, 9:59 PM

I saw the post about the rollout of data jurisdictions. Love it! Will it be possible to enable retroactively for existing DBs? I've got a project in staging that's about to go live and I really don't want to recreate the DB

Zetax•11/10/25, 2:41 AM

There should definitely be something like development branches for D1. This would be a great addition as it would compliment preview deployments from git repositories. That way, developers could test database changes in a staging enviroment without modifying the prod database.

CCemal Hi, I have a question about D1. I'm using it together with Drizzle ORM. I have a...

lambrospetrou•11/10/25, 9:27 AM

If you can build all the queries you want to run in a transaction before hand, you can send them all in a single

batch()

batch()

query and they will all run within the same transaction.
So, for example, if you want to update two tables, or two different rows but with separate queries, you can prepare both of them and send them together.
https://developers.cloudflare.com/d1/worker-api/d1-database/#batch

Cloudflare Docs

D1 Database

To interact with your D1 database from your Worker, you need to access it through the environment bindings provided to the Worker (env).

Llambrospetrou If you can build all the queries you want to run in a transaction before hand, y...

Cemal•11/10/25, 9:35 AM

This is great — but could it still lead to a race condition issue?

CCemal This is great — but could it still lead to a race condition issue?

lambrospetrou•11/10/25, 9:40 AM

You can always add race conditions if you split something that should be a single transaction across multiple requests.
I am just mentioning that there is the

batch()

batch()

method for running independent queries in a transaction.

If you need to intervleave JS code with SQL queries, then D1 cannot do that, and your best bet would be SQLite DOs.

Cemal•11/10/25, 9:55 AM

I got it, thanks.

Mitya•11/10/25, 10:12 AM

In both the CF dash and via the D1 REST API's list DBs endpoint, it says my database has zero tables. This isn't true; it has 2, and I can successfully query data. These tables have existed for several days. Why would this be happening?

MMitya In both the CF dash and via the D1 REST API's list DBs endpoint, it says my data...

lambrospetrou•11/10/25, 11:06 AM

I believe the GET database details should give you the correct information.
The list endpoint I think returns stale data due to a control plane change few weeks ago. I will report it internally to be fixed.

thipperz•11/10/25, 3:35 PM

About database scaling limits, is there a way I can check my current usage?

Tthipperz About database scaling limits, is there a way I can check my current usage?

lambrospetrou•11/10/25, 3:46 PM

The graphql API returns rows read/written and db sizes per database. The dashboard also shows that data in the metrics tab.

Jael•11/10/25, 8:58 PM

Im curious (and forgive my stupidity here) if there's an officiall or unofficially blessed way to do D1 multitenancy that allows for using parameters in queries. Everything I'm seeing seems to indicate people are doing like hash sharding and stuff to allow them to leverage worker bindings when they scale a per tenant or per entity D1 architechture. Im trying to do a rewrite to pivot that direction (multitenancy) but you can't bind parameters to multi statement queries over http (im not even sure you could do that with bindings I've never tried). And it seems the efficiency and performance hit of doing an independant api call for each query would be pretty bad... Should I just be abandoning parameters and doing my own sanitization so I can batch calls over the API with all my values written into it? or am missing a "blessed" pathway here?

Jael•11/10/25, 9:13 PM

It just seems like hacky "redeploys" where I eternally bind more D1 databases to my wrangler.json can't be the best way to go about this... but also I don't want to run unsafe SQL statements and I don't want to run an api call for each query... If there's no official way I'll figure something out but it seems like I must be missing something here.

Alternatively, is this something I should be solving with Queues?

JJael It just seems like hacky "redeploys" where I eternally bind more D1 databases to...

lambrospetrou•11/10/25, 9:55 PM

If you want thousands of DBs (tenants) you should use SQLite Durable Objects. Same underlying SQLite engine as D1, but you can dynamically create thousands of instances programmatically.

lambrospetrou•11/10/25, 9:59 PM

Hey folks, we updated the section "How much work can a D1 database do?" in our docs: https://developers.cloudflare.com/d1/platform/limits/#how-much-work-can-a-d1-database-do

It tries to give a guidance on what to expect, and set expectations a bit more realisitically. Let me know how you find it.

Cloudflare Docs

Limits

Cloudflare also offers other storage solutions such as Workers KV, Durable Objects, and R2. Each product has different advantages and limits. Refer to Choose a data or storage product to review which storage option is right for your use case.

Llambrospetrou If you want thousands of DBs (tenants) you should use SQLite Durable Objects. Sa...

Jael•11/10/25, 10:28 PM

looks like I have some reading to do thanks

JJael looks like I have some reading to do thanks 🙂

lambrospetrou•11/10/25, 10:38 PM

Start here: https://developers.cloudflare.com/durable-objects/concepts/what-are-durable-objects/

Cloudflare Docs

What are Durable Objects?

A Durable Object is a special kind of Cloudflare Worker which uniquely combines compute with storage. Like a Worker, a Durable Object is automatically provisioned geographically close to where it is first requested, starts up quickly when needed, and shuts down when idle. You can have millions of them around the world. However, unlike regular Wo...

thipperz•11/11/25, 7:15 PM

Are there any plans to add more read replicas locations? i.e. South America

Chaika•11/11/25, 7:32 PM

(which aren't in South America yet)

Chaika•11/11/25, 7:32 PM

not been any new DO regions for a bit, middle of last year they said they were trying to get India and then South America by end of 2024...
durable-objects

akicookz•11/12/25, 7:54 PM

anyway to connect d1 with a db GUI. Looked through docs and I think it is not possible. just wanted to make sure I have not missed a work around or something.
Thanks

Aakicookz anyway to connect d1 with a db GUI. Looked through docs and I think it is not po...

1984 Ford Laser•11/12/25, 8:00 PM

https://d1-studio.com/

d1-studio

The first native studio for D1 databases

11984 Ford Laser https://d1-studio.com/

akicookz•11/12/25, 8:02 PM

Does this let me pin queries? Cloudflare D1 also has a GUI but it's limited. I have some long admin queries I wanna keep around the db instead of my notepad

AAlper Dincer hi, I need help on the following problem at D1: https://community.cloudflare.co...

gruntlord6•11/13/25, 12:20 AM

You need to optimize your query, whatever you are doing is more then 128mb which is how much in memory state the d1 durable object has.

Have you tried splitting the reads into paginated requests rather then just selecting all 26 million rows?

AAlper Dincer hi, I need help on the following problem at D1: https://community.cloudflare.co...

1984 Ford Laser•11/13/25, 4:32 AM

You definitely wanna add the index before having 26mil rows. I would also consider if there are ways to split the data up into separate tables, or only select a subset at a time

Ggruntlord6 You need to optimize your query, whatever you are doing is more then 128mb which...

lambrospetrou•11/13/25, 7:34 AM

As others suggested, this is one of the most common ways folks hit the SQLite memory issues with D1 (and Durable Objects). Doing aggregations across the whole table of millions of rows is too easy to hit the memory/CPU limits.

In your specific query: can you do multiple queries with "data filtering" in ranges so that the rows are filtered out?

Although, that would need an index to work properly if you don't already have one, but it's worth trying.

AAlper Dincer Thanks for the suggestions, but I will try to go with Parquet or other alternati...

Kevin•11/13/25, 10:26 AM

Isn't hyperdrive and option for you?

lambrospetrou•11/13/25, 4:59 PM

Hey folks, a quick update for those that enabled read replication in the past few weeks but didn't see replicas appearing. There was a control plane bug that in some edge cases even though the API persisted the decision, the database did not actually enable replicas, therefore no replica was serving queries.

We released a mitigation last Friday for this to stop happening in new cases, and we rolled out another fix today to retroactively enable replicas for those that have the read replication setting enabled.

If you try out read replication and even after sending some traffic for a few minutes you still don't see replicas serving requests please reach out. You can see if replicas are serving queries in the dashboard UI, and also in each query response from the property .

Ronald•11/14/25, 1:31 PM

Hello

I'm new to this product, and as per the Docs it says data IS encrypted at rest/transit, so does it mean that I could store passwords/sensitive info without any further encryption? Without having for example a Worker to encrypt/decrypst a user password?

RRonald Hello 👋 I'm new to this product, and as per the Docs it says data IS encrypted ...

PhoenixSpace•11/14/25, 1:33 PM

You should still encrypt it

PhoenixSpace•11/14/25, 1:33 PM

It’s encrypted at rest, but there is still an attack vector of if someone gains access to your cloudflare account through a mistake. You should never be able to access someone’s plaintext password period

PhoenixSpace•11/14/25, 1:35 PM

To be more specific, cloudflare encrypts D1 at rest, but passwords should be one way hashed for security which is different

PPhoenixSpace It’s encrypted at rest, but there is still an attack vector of if someone gains ...

Ronald•11/14/25, 1:35 PM

Yup, makes sense

Ronald•11/14/25, 1:36 PM

Thanks @PhoenixSpace