libmtbl1 binary package in Ubuntu Focal arm64

 mtbl is a C library implementation of the Sorted String Table (SSTable)
 data structure, based on the SSTable implementation in the open source
 Google LevelDB library. An SSTable is a file containing an immutable
 mapping of keys to values. Keys are stored in sorted order, with an
 index at the end of the file allowing keys to be located quickly.
 .
 mtbl is not a database library. It does not provide an updateable
 key-value data store, but rather exposes primitives for creating,
 searching and merging SSTable files. Unlike databases which use
 the SSTable data structure internally as part of their data store,
 management of SSTable files -- creation, merging, deletion, combining
 of search results from multiple SSTables -- is left to the
 discretion of the mtbl library user.
 .
 This package contains the shared library for libmtbl.

Source package