sqlite3_txn_state()

The sqlite3_txn_state(D,S) interface returns the current transaction state of schema S in database connection D. If S is NULL, then the highest transaction state of any schema on database connection D is returned. Transaction states are (in order ... 

SQLite is Transactional A transactional database is one in which all changes and queries appear to be Atomic, Consistent, Isolated, and Durable (ACID). SQLite implements serializable transactions that are atomic, consistent, isolated, and durable, even if the transaction is interrupted ... 

 ... Read transactions versus write transactions SQLite supports multiple simultaneous read transactions coming from separate database connections, possibly in separate threads or processes, but only one simultaneous write transaction. A read transaction is used for reading only. A write transaction allows ... 

sqlite3_snapshot_open()

The sqlite3_snapshot_open(D,S,P) interface either starts a new read transaction or upgrades an existing one for schema S of database connection D such that the read transaction refers to historical snapshot P, rather than the most recent change ... 

sqlite3_db_cacheflush()

If a write-transaction is open on database connection D when the sqlite3_db_cacheflush(D) interface invoked, any dirty pages in the pager-cache that are not currently in use are written out to disk. A dirty page may be in ... 

 ... SQLITE_READ, SQLITE_SELECT, SQLITE_TRANSACTION, SQLITE_UPDATE, SQLITE_ATTACH, SQLITE_DETACH ... 

The sqlite3_set_authorizer() interface registers a callback function that is invoked to authorize certain SQL statement actions. The second parameter to the callback is an integer code that specifies what action is being authorized. These are the integer action codes that ... 

 ... Transaction Nesting Rules The last transaction started will be the first transaction committed or rolled back. The BEGIN command only works if the transaction stack is empty, or in other words if there are no pending transactions. If the transaction ... 

SQLITE_TXN_NONE, SQLITE_TXN_READ, SQLITE_TXN_WRITE

These constants define the current transaction state of a database file. The sqlite3_txn_state(D,S) interface returns one of these constants in order to describe the transaction state of schema S in database connection D. SQLITE_TXN_NONE The SQLITE_TXN_NONE state means ... 

sqlite3_snapshot_get()

 ... If there is not already a read-transaction open on schema S when this function is called, one is opened automatically. If a read-transaction is opened by this function, then it is guaranteed that the returned snapshot object may ... 

 ... When a read transaction starts, that reader continues to see an unchanging "snapshot" of the database file as it existed at the moment in time when the read transaction started. Any write transactions that commit while the read transaction is ...