SQLITE_IOCAP_ATOMIC(3)

SQLITE_IOCAP_ATOMIC(3) | Library Functions Manual | SQLITE_IOCAP_ATOMIC(3)

# NAME

SQLITE_IOCAP_ATOMIC, SQLITE_IOCAP_ATOMIC512, SQLITE_IOCAP_ATOMIC1K, SQLITE_IOCAP_ATOMIC2K, SQLITE_IOCAP_ATOMIC4K, SQLITE_IOCAP_ATOMIC8K, SQLITE_IOCAP_ATOMIC16K, SQLITE_IOCAP_ATOMIC32K, SQLITE_IOCAP_ATOMIC64K, SQLITE_IOCAP_SAFE_APPEND, SQLITE_IOCAP_SEQUENTIAL, SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN, SQLITE_IOCAP_POWERSAFE_OVERWRITE, SQLITE_IOCAP_IMMUTABLE — Device Characteristics

# SYNOPSIS

#define SQLITE_IOCAP_ATOMIC
#define SQLITE_IOCAP_ATOMIC512
#define SQLITE_IOCAP_ATOMIC1K
#define SQLITE_IOCAP_ATOMIC2K
#define SQLITE_IOCAP_ATOMIC4K
#define SQLITE_IOCAP_ATOMIC8K
#define SQLITE_IOCAP_ATOMIC16K
#define SQLITE_IOCAP_ATOMIC32K
#define SQLITE_IOCAP_ATOMIC64K
#define SQLITE_IOCAP_SAFE_APPEND
#define SQLITE_IOCAP_SEQUENTIAL
#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
#define SQLITE_IOCAP_POWERSAFE_OVERWRITE
#define SQLITE_IOCAP_IMMUTABLE

# DESCRIPTION

The xDeviceCharacteristics method of the sqlite3_io_methods object returns an integer which is a vector of these bit values expressing I/O characteristics of the mass storage device that holds the file that the sqlite3_io_methods refers to.
The SQLITE_IOCAP_ATOMIC property means that all writes of any size are atomic. The SQLITE_IOCAP_ATOMICnnn values mean that writes of blocks that are nnn bytes in size and are aligned to an address which is an integer multiple of nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means that when data is appended to a file, the data is appended first then the size of the file is extended, never the other way around. The SQLITE_IOCAP_SEQUENTIAL property means that information is written to disk in the same order as calls to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that after reboot following a crash or power loss, the only bytes in a file that were written at the application level might have changed and that adjacent bytes, even bytes within the same sector are guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN flag indicates that a file cannot be deleted when open. The SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on read-only media and cannot be changed even by processes with elevated privileges.

# SEE ALSO

sqlite3_io_methods(3)

March 11, 2017 | NetBSD 8.3