By default in PHP 7.3.11
lmdb database size is fixed by 1MB and no way to change it. Bug about it: https://bugs.php.net/bug.php?id=78808
This gist provide hotfix for this behaviour. (But it may be easier to create databases in python or from another lib?)
brew uninstall --ignore-dependencies lmdb brew update patch /usr/local/Homebrew/Library/Taps/homebrew/homebrew-core/Formula/lmdb.rb < patch-brew-lmdb.rb brew install --build-from-source lmdb
Reinstall php if it not helped.
PS: this patch also raises database readers for better use in multi-threaded mode (but readers can also be increased by changing the environment variable