-type backup_options() ::
    #{from => unicode:chardata(),
      to => unicode:chardata(),
      step => pos_integer(),
      progress => progress_callback()}.

Backup options

• from: source database name, <<"main">> is the default
• to: destination database name, takes from value as the default
• stop: backup step, pages. Default is 64
• progress: progress callback to invoke after finishing the next step

-type connect_flag() :: memory | uri | shared.

SQLite connections flags specification

Normally used to specify an in-memory database: flags => [memory].

  Db1 = sqlite:open("file::mem:", #{flags => [shared, memory, uri]}),
  Db2 = sqlite:open("file::mem:", #{flags => [shared, memory, uri]}),

• memory: enables SQLITE_OPEN_MEMORY flag
• uri: enables SQLITE_OPEN_URI flag
• shared: enables SQLITE_OPEN_SHAREDCACHE flag

-type connect_options() ::
    #{mode => read_only | read_write | read_write_create,
      flags => [connect_flag()],
      busy_timeout => non_neg_integer()}.

SQLite connection options.

• mode: file open mode, the default is read_write_create
• flags: SQLite connection flags specification
• busy_timeout: specifies SQLite busy timeout. NOTE: using this setting may easily exhaust all ERTS Dirty I/O schedulers. Prefer WAL mode instead

-type connection_status() ::
    #{lookaside_memory => lookaside_memory(),
      pager_cache_memory => pager_cache_memory(),
      schema => integer(),
      statement => integer(),
      deferred_fks => integer()}.

SQLite connection status

• schema: the approximate number of bytes of heap memory used to store the schema for all databases associated with the connection (current value of SQLITE_DBSTATUS_SCHEMA_USED)
• statement: the approximate number of bytes of heap and lookaside memory used by all prepared statements associated with the database connection (current value of SQLITE_DBSTATUS_STMT_USED)
• deferred_fks: returns zero for the current value if and only if all foreign key constraints (deferred or immediate) have been resolved (current value of SQLITE_DBSTATUS_DEFERRED_FKS)

-type lookaside_memory() ::
    #{used => integer(),
      max => integer(),
      hit => integer(),
      miss_size => integer(),
      miss_full => integer()}.

SQLite connection lookaside memory usage

• used: the current number of lookaside memory slots currently checked out (current value of SQLITE_DBSTATUS_LOOKASIDE_USED)
• max: high watermark of SQLITE_DBSTATUS_LOOKASIDE_USED
• hit: number of malloc attempts that were satisfied using lookaside memory (high watermark of SQLITE_DBSTATUS_LOOKASIDE_HIT)
• miss_size: the number malloc attempts that might have been satisfied using lookaside memory but failed due to the amount of memory requested being larger than the lookaside slot size (high watermark of SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE)
• miss_full: the number malloc attempts that might have been satisfied using lookaside memory but failed due to all lookaside memory already being in use (high watermark of SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL)

-type pager_cache_memory() ::
    #{used => integer(),
      shared => integer(),
      hit => integer(),
      miss => integer(),
      write => integer(),
      spill => {Current :: integer(), Max :: integer()}}.

SQLite connection pager cache memory usage

• used: the approximate number of bytes of heap memory used by all pager caches associated with the database connection (current value of SQLITE_DBSTATUS_CACHE_USED)
• shared: current value of SQLITE_DBSTATUS_CACHE_USED_SHARED
• hit: the number of pager cache hits that have occurred (current value of SQLITE_DBSTATUS_CACHE_HIT)
• miss: the number of pager cache misses that have occurred (current value of SQLITE_DBSTATUS_CACHE_MISS)
• write: the number of dirty cache entries that have been written to disk (current value of SQLITE_DBSTATUS_CACHE_WRITE)
• spill: the number of dirty cache entries that have been written to disk in the middle of a transaction due to the page cache overflowing. Both values of SQLITE_DBSTATUS_CACHE_SPILL

-type parameters() :: [parameter()] | #{atom() | iolist() | pos_integer() => parameter()}.

Positional and named parameters.

-type prepare_options() :: #{persistent => boolean(), no_vtab => boolean()}.

Prepared statement creation flags

• persistent: The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner that the prepared statement will be retained for a long time and probably reused many times
• no_vtab: The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler to return an error (error code SQLITE_ERROR) if the statement uses any virtual tables

-type statement_info() ::
    #{fullscan_step => integer(),
      sort => integer(),
      autoindex => integer(),
      vm_step => integer(),
      reprepare => integer(),
      run => integer(),
      filter_miss => integer(),
      filter_hit => integer(),
      memory_used => integer()}.

Prepared statement statistics

-type system_info() ::
    #{memory_used => {Cur :: integer(), Max :: integer()},
      page_cache =>
          {Size :: integer(),
           Used :: integer(),
           Max :: integer(),
           Overflow :: integer(),
           OverflowMax :: integer()},
      malloc => {Size :: integer(), Count :: integer(), Max :: integer()},
      version => binary()}.

Status information about the performance of SQLite