SQLite has a system called pragmas: https://www.sqlite.org/pragma.html . Pragmas are an important part of the reason that SQLite is low-or-zero configuration, and part of its success in embedded applications. Mostly the LMDB backend is entirely transparent to applications, but some pragmas just don't make sense with LMDB. After technical review, the information in this issue needs to appear in the LMDB part of the backend-specific documentation.
For the LMDB backend some pragmas won't work and should almost certainly be ignored, which is what is done for any error in a pragma including specifying a non-existent pragma.
danshearer
commented
3 years ago
SQLite has a system called pragmas: https://www.sqlite.org/pragma.html . Pragmas are an important part of the reason that SQLite is low-or-zero configuration, and part of its success in embedded applications. Mostly the LMDB backend is entirely transparent to applications, but some pragmas just don't make sense with LMDB. After technical review, the information in this issue needs to appear in the LMDB part of the backend-specific documentation.
For the LMDB backend some pragmas won't work and should almost certainly be ignored, which is what is done for any error in a pragma including specifying a non-existent pragma.
PRAGMA legacy_file_format
PRAGMA journal_mode = DELETE | TRUNCATE | PERSIST | MEMORY | WAL | OFF
PRAGMA auto_vacuum
PRAGMA incremental_vacuum
PRAGMA journal_size_limit
and probably
PRAGMA cache_size
and possibly
PRAGMA fullfsync