Isar Database

Limitations

As you know, Isar works on mobile devices and desktops running on the VM as well as Web. Both platforms are very different and have different limitations.

VM Limitations

  • Only the first 1024 bytes of a string can be used for a prefix where-clause
  • Objects can only be 16MB in size

Web Limitations

Isar Plus on the web now runs on SQLite compiled to WebAssembly. Chrome and Edge persist data inside the Origin Private File System (OPFS); Safari, Firefox, and older Chromium builds fall back to an IndexedDB-backed VFS. The OPFS backend mirrors native SQLite behaviour, while the fallback still carries a few browser-imposed constraints:

  • Use the asynchronous APIs on the web; synchronous collection helpers throw UnsupportedError.
  • Text helpers such as Isar.splitWords() and .matches() remain unimplemented for the web engine.
  • Schema migrations are not validated as strictly as on the VM, so double-check breaking changes during releases.
  • When the IndexedDB fallback is active, some return values (for example delete() counts) may differ from native SQLite and auto-increment counters are not reset by clear().