[GitHub] [arrow] csjh opened a new issue, #36395: Setting value of row in table with strings truncates longer strings

["csjh (via GitHub)" <gi...@apache.org>]

csjh opened a new issue, #36395:
URL: https://github.com/apache/arrow/issues/36395

   ### Describe the bug, including details regarding any error messages, version, and platform.
   
   ```js
   const table = tableFromJSON([{ name: "Bill" }, { name: "Samantha" }]);
   table.set(0, table.get(1));
   // table.get(0).name is now "Sama"
   ```
   On version 11.0.0, MacOS 13.14
   
   I'm not 100% sure that this isn't the intended behaviour, but better safe than sorry. The behaviour I would expect is for `table.get(0)` to be identical to `table.get(1)`.
   
   ### Component(s)
   
   JavaScript


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Re: [I] [JS] Setting value of row in table with strings truncates longer strings [arrow]

["domoritz (via GitHub)" <gi...@apache.org>]

domoritz closed issue #36395: [JS] Setting value of row in table with strings truncates longer strings
URL: https://github.com/apache/arrow/issues/36395


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Re: [I] [JS] Setting value of row in table with strings truncates longer strings [arrow]

["domoritz (via GitHub)" <gi...@apache.org>]

domoritz commented on issue #36395:
URL: https://github.com/apache/arrow/issues/36395#issuecomment-1878792836

   This is a bit surprising but also expected. The memory for the variable width strings is allocated in one block so writing different content in that memory with `set` will not work correctly. In general, Arrow data structures are optimized for reading and if you need to make changes, you are better off making a new data structure. Supporting write here would mean we need to move all the memory for the strings in the vector around. 
   
   If you only have a limited number of strings, you can use a dictionary and then re-assigning a value should work. 
   
   Closing as working as expected for now. 


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