Ah, ok, understood. I don't think that's a compelling reason to fix our maximum database name length at 238.
CouchDB 4.0 will be the first version of CouchDB where we're not coupled to the filesystem for this list. 256 is very common for a filesystem filename length limit (though not universal) so I don't think our history should dictate an odd (fine, _even_) choice of 238. B. > On 4 May 2020, at 20:41, Nick Vatamaniuc <[email protected]> wrote: > > It will prevent replicating from db created in 4.0 which has a name > longer than 238 (say 250) back to 2.x/3.x if the user intends to keep > the same database name on both systems, that's what I meant. > > On Mon, May 4, 2020 at 3:15 PM Robert Samuel Newson <[email protected]> > wrote: >> >> The 'timestamp in filename' is only on the internal shards, which would not >> be part of a replication between 2.x/3.x and 4.x. >> >> In any case, Nick is suggesting lowering from 256 charts to 238 chars to >> leave room for these things that won't be there. I confess I don't >> understand the reasoning. >> >> B. >> >>> On 4 May 2020, at 20:04, Joan Touzet <[email protected]> wrote: >>> >>> I suspect he means when replicating back to a 3.x or 2.x cluster. >>> >>> On 2020-05-04 3:03 p.m., Robert Samuel Newson wrote: >>>> But we don't need to add a file extension or a timestamp to database names. >>>> B. >>>>> On 4 May 2020, at 18:42, Nick Vatamaniuc <[email protected]> wrote: >>>>> >>>>> Hello everyone, >>>>> >>>>> Good idea, +1 with one minor tweak: database name length in versions >>>>> <4.0 was restricted by the maximum file name on whatever file system >>>>> the server was running on. In practice that was 255, then there is an >>>>> extension and a timestamp in the filename which made the db name limit >>>>> be 238 so I suggest to use that instead. >>>>> >>>>> -Nick >>>>> >>>>> On Mon, May 4, 2020 at 11:51 AM Robert Samuel Newson <[email protected]> >>>>> wrote: >>>>>> >>>>>> Hi, >>>>>> >>>>>> I think I speak for many in accepting the risk that we're excluding doc >>>>>> ids formed from 4096-bit RSA signatures. >>>>>> >>>>>> I don't think I made it clear but I think these should be fixed limits >>>>>> (i.e, not configurable) in order to ensure inter-replication between >>>>>> couchdb installations wherever they are. >>>>>> >>>>>> B. >>>>>> >>>>>>> On 4 May 2020, at 10:52, Ilya Khlopotov <[email protected]> wrote: >>>>>>> >>>>>>> Hello, >>>>>>> >>>>>>> Thank you Robert for starting this important discussion. I think that >>>>>>> the values you propose make sense. >>>>>>> I can see a case when user would use hashes as document ids. All >>>>>>> existent hash functions I am aware of should return data which fit into >>>>>>> 512 characters. There is only one case which doesn't fit into 512 >>>>>>> limit. If user would decide to use RSA signatures as document ids and >>>>>>> they use 4096 bytes sized keys the signature size would be 684 bytes. >>>>>>> >>>>>>> However in this case users can easily replace signatures with hashes of >>>>>>> signatures. So I wouldn't worry about it to much. 512 sounds plenty to >>>>>>> me. >>>>>>> >>>>>>> +1 to set hard limits on db name size and doc id size with proposed >>>>>>> values. >>>>>>> >>>>>>> Best regards, >>>>>>> iilyak >>>>>>> >>>>>>> On 2020/05/01 18:36:45, Robert Samuel Newson <[email protected]> wrote: >>>>>>>> Hello, >>>>>>>> >>>>>>>> There are other threads related to doc size (etc) limits for CouchDB >>>>>>>> 4.0, motivated by restrictions in FoundationDB, but we haven't >>>>>>>> discussed database name length and doc id length limits. These are >>>>>>>> encoded into FoundationDB keys and so we would be wise to forcibly >>>>>>>> limit their length from the start. >>>>>>>> >>>>>>>> I propose 256 character limit for database name and 512 character >>>>>>>> limit for doc ids. >>>>>>>> >>>>>>>> If you can't uniquely identify your database or document within those >>>>>>>> limits I argue that you're doing something wrong, and the limits here, >>>>>>>> while making FDB happy, are an aid to sensible application design. >>>>>>>> >>>>>>>> Does anyone want higher or lower limits? Comments pls. >>>>>>>> >>>>>>>> B. >>>>>>>> >>>>>>>> >>>>>> >>
