html_url,issue_url,id,node_id,user,created_at,updated_at,author_association,body,reactions,issue,performed_via_github_app
https://github.com/simonw/datasette/pull/1870#issuecomment-1745568725,https://api.github.com/repos/simonw/datasette/issues/1870,1745568725,IC_kwDOBm6k_c5oC0PV,2495794,2023-10-03T19:12:37Z,2023-10-03T19:12:37Z,NONE,"Hello! Resurrecting this issue since we're running into something similar with data.catalyst.coop as our database files have ballooned up to several GB. Our Cloud Run revisions now require huge amounts of RAM to start up without receiving a SIGBUS.
I'd love to see this fix merged in. It sounds like we want to make the immutable/read-only mode decision more flexible before doing so, so that we can use `ro` in Docker and `immutable` outside. If that sounds right, I'm happy to take a crack at adding that as a command-line flag or something that gets set automatically based on the expected execution environment.","{""total_count"": 1, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 1}",1426379903,
https://github.com/simonw/datasette/pull/1870#issuecomment-1295667649,https://api.github.com/repos/simonw/datasette/issues/1870,1295667649,IC_kwDOBm6k_c5NOlHB,536941,2022-10-29T00:52:43Z,2022-10-29T00:53:43Z,CONTRIBUTOR,"> Are you saying that I can build a container, but then when I run it and it does `datasette serve -i data.db ...` it will somehow modify the image, or create a new modified filesystem layer in the runtime environment, as a result of running that `serve` command?
Somehow, `datasette serve -i data.db` will lead to the `data.db` being modified, which will trigger a [copy-on-write](https://docs.docker.com/storage/storagedriver/#the-copy-on-write-cow-strategy) of `data.db` into the read-write layer of the container.
I don't understand **how** that happens.
it kind of feels like a bug in sqlite, but i can't quite follow the sqlite code.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1426379903,
https://github.com/simonw/datasette/pull/1870#issuecomment-1295660092,https://api.github.com/repos/simonw/datasette/issues/1870,1295660092,IC_kwDOBm6k_c5NOjQ8,9599,2022-10-29T00:25:26Z,2022-10-29T00:25:26Z,OWNER,"Saw your comment here too: https://github.com/simonw/datasette/issues/1480#issuecomment-1271101072
> switching from `immutable=1` to `mode=ro` completely addressed this. see https://github.com/simonw/datasette/issues/1836#issuecomment-1271100651 for details.
So maybe we need a special case for containers that are intended to be run using Docker - the ones produced by `datasette package` and `datasette publish cloudrun`? Those are cases where the `-i` option should actually be opened in read-only mode, not immutable mode.
Maybe a `datasette serve --irw data.db` option for opening a file in immutable-but-actually-read-only mode? Bit ugly though.
I should run some benchmarks to figure out if `immutable` really does offer significant performance benefits.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1426379903,
https://github.com/simonw/datasette/pull/1870#issuecomment-1295657771,https://api.github.com/repos/simonw/datasette/issues/1870,1295657771,IC_kwDOBm6k_c5NOisr,9599,2022-10-29T00:19:03Z,2022-10-29T00:19:03Z,OWNER,"Just saw your comment here: https://github.com/simonw/datasette/issues/1836#issuecomment-1272357976
> when you are running from docker, you **always** will want to run as `mode=ro` because the same thing that is causing duplication in the inspect layer will cause duplication in the final container read/write layer when `datasette serve` runs.
I don't understand this. My mental model of how Docker works is that the image itself is created using `docker build`... but then when the image runs later on (`docker run`) the image itself isn't touched at all.
Are you saying that I can build a container, but then when I run it and it does `datasette serve -i data.db ...` it will somehow modify the image, or create a new modified filesystem layer in the runtime environment, as a result of running that `serve` command?","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1426379903,
https://github.com/simonw/datasette/pull/1870#issuecomment-1294285471,https://api.github.com/repos/simonw/datasette/issues/1870,1294285471,IC_kwDOBm6k_c5NJTqf,536941,2022-10-28T01:06:03Z,2022-10-28T01:06:03Z,CONTRIBUTOR,"as far as i can tell, [this is where the ""immutable"" argument is used](https://github.com/sqlite/sqlite/blob/c97bb14fab566f6fa8d967c8fd1e90f3702d5b73/src/pager.c#L4926-L4931) in sqlite:
```c
pPager->noLock = sqlite3_uri_boolean(pPager->zFilename, ""nolock"", 0);
if( (iDc & SQLITE_IOCAP_IMMUTABLE)!=0
|| sqlite3_uri_boolean(pPager->zFilename, ""immutable"", 0) ){
vfsFlags |= SQLITE_OPEN_READONLY;
goto act_like_temp_file;
}
```
so it does set the read only flag, but then has a goto.","{""total_count"": 0, ""+1"": 0, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",1426379903,
https://github.com/simonw/datasette/pull/1870#issuecomment-1294238862,https://api.github.com/repos/simonw/datasette/issues/1870,1294238862,IC_kwDOBm6k_c5NJISO,22429695,2022-10-27T23:44:25Z,2022-10-27T23:44:25Z,NONE,"# [Codecov](https://codecov.io/gh/simonw/datasette/pull/1870?src=pr&el=h1&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Simon+Willison) Report
Base: **92.55**% // Head: **92.55**% // No change to project coverage :thumbsup:
> Coverage data is based on head [(`4faa4fd`)](https://codecov.io/gh/simonw/datasette/pull/1870?src=pr&el=desc&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Simon+Willison) compared to base [(`bf00b0b`)](https://codecov.io/gh/simonw/datasette/commit/bf00b0b59b6692bdec597ac9db4e0b497c5a47b4?el=desc&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Simon+Willison).
> Patch has no changes to coverable lines.
Additional details and impacted files
```diff
@@ Coverage Diff @@
## main #1870 +/- ##
=======================================
Coverage 92.55% 92.55%
=======================================
Files 35 35
Lines 4432 4432
=======================================
Hits 4102 4102
Misses 330 330
```
| [Impacted Files](https://codecov.io/gh/simonw/datasette/pull/1870?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Simon+Willison) | Coverage Δ | |
|---|---|---|
| [datasette/app.py](https://codecov.io/gh/simonw/datasette/pull/1870/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Simon+Willison#diff-ZGF0YXNldHRlL2FwcC5weQ==) | `94.30% <ø> (ø)` | |
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