https://sqlite.org/sqlar/doc/trunk/README.md It says > The file is compressed if length(sqlar.blob)<sqlar.sz and is stored as plaintext if length(sqlar.blob)==sqlar.sz. But it also says > the zlib format contains a two byte compression-type indentification header (0x78 0x9c) and a 4-byte checksum at the end Could it be possible that length(sqlar.blob)==sqlar.sz in the latter case as the header/checksum can make up the length reduction of the compression?