Documentation Source Text

  A default build of SQLite, if a [DELETE] statement has no WHERE clause
  and operates on a table with no triggers, an optimization occurs that
  causes the DELETE to occur by dropping and recreating the table.  
  Dropping and recreating a table is usually much faster than deleting
  the table content row by row.  This is the "truncate optimization".
}

COMPILE_OPTION {SQLITE_OMIT_UNIQUE_ENFORCEMENT} {
  This macro is used to omit support for enforcing UNIQUE constraints.
  Unique constraints may still be defined, and all code and optimizations
  function as if they are enforced, however, the OP_IsUnique VDBE 
  opcode is not generated.  This may be useful for users who can 
  guarantee uniqueness of inputs, or have other means of enforcing
  the constraint.  See also [SQLITE_OMIT_CHECK], [EXPLAIN].
}

COMPILE_OPTION {SQLITE_OMIT_UTF16} {
  This macro is used to omit support for UTF16 text encoding. When this is
  defined all API functions that return or accept UTF16 encoded text are
  unavailable. These functions can be identified by the fact that they end
  with '16', for example [sqlite3_prepare16()], [sqlite3_column_text16()] and
  [sqlite3_bind_text16()].
}