Hello,
I would extend the maxLength for notes and descr parts to 1000 characters. In our current db the longest note is 671 characters.
There are a couple of attributes in the dictionary that have a maxLength below 30. While for some it seems logical I have some concerns for others like ID. Why not keeping 30 for instrumentID and polygonID for instance?
Thank you.
Hi,
I am coming back to you for this?
Thanks
Thank you for coming back to this one and reminding me to respond on this as well! Apologies for the slow response on this one as well.
In the interest of replying quickly and getting this conversation moving so it doesn’t slip off my radar again, I may give a somewhat unsatisfactory answer here as a placeholder while I collect some additional information.
I think it is entirely possible that we could extend the maxLength for the notes and descr fields. Your point is a very salient one, and I think it makes a lot of sense. For IDs too, I think you’re right that allowing for longer IDs may be wise.
I don’t remember off the top of my head what the rationale was for some of these shorter character lengths. I might ping @Sorin to see if maybe he knows. I think that for headers and some other fields, we were trying to abide by constraints within the ARCGIS system that limits character length and something in the 300s range? But Sorin, I’m sure you’ll know better than I.
I’ll also bring this up at our working group meeting next Thursday to see if anyone else might now or have any objections to increasing the max length.
Thank you again for reminding me on this one, and apologies again for taking so long to reply!
Most modern databases support field names at least 63 characters in length (and at most 128) , but Oracle is limited to 30 bytes, INFO databases used by ArcGIS has max 16 characters and the ancient dBase has 10 characters.
All the databases have text data types that support at least 254 characters (dBase and ArcGIS) but most of them can store up to 1-4GB in a cell.
I don’t know of anyone using dBase these days, but Oracle is still widely used so that’s why we have a hard limit of 30 characters for attribute (column) names.
For maximum database interoperability we recommend limiting most of the text fields to 254 characters but for notes, description, summary and refLink fields this is clearly not enough. I would still try to limit these to 4000 characters for interoperability with Oracle’s VARCHAR2 data type.
For geoWKT you should allow as much as your database supports - I’d say min 1GB, to allow for complex polygons.
However, if interoperability is not one of your priorities, keep in mind that we don’t really impose a limit on the number of characters that you should store in a varchar field, so do as you please and your database supports :).
I think @wastewater_belgium question wasn’t about the length of the variable name, but for the value for the notes.
I am open to longer character limits for notes and desc, but it would be helpful to have a reasonable limit (1000?) It is too large, then we’d probalby want a link out or another table.