sqlite3_open(), sqlite3_open16()

 ... For historical reasons, if opening in read-write mode fails due to OS-level permissions, an attempt is made to open it in read-only mode. sqlite3_db_readonly() can be used to determine whether the database is actually read-write. SQLITE_OPEN_READWRITE ... 

sqlite3_snapshot_get()

 ... The database handle must not be in autocommit mode. Schema S of database connection D must be a WAL mode database. There must not be a write transaction open on schema S of database connection D. One or more transactions ... 

sqlite3_snapshot_open()

 ... In order to succeed, the database connection must not be in autocommit mode when sqlite3_snapshot_open(D,S,P) is called. If there is already a read transaction open on schema S, then the database handle must have no active statements ... 

2.1. Transaction Level Locking SQLite connections can open two kinds of transactions, read and write transactions. This is not done explicitly, a transaction is implicitly a read-transaction until it first writes to a database table, at which point it becomes a write-transaction ... 

sqlite3_enable_shared_cache()

 ... The cache sharing mode set by this interface effects all subsequent calls to sqlite3_open(), sqlite3_open_v2(), and sqlite3_open16(). Existing database connections continue to use the sharing mode that was in effect at the time they were opened. This routine returns SQLITE_OK ... 

9. Sometimes Queries Return SQLITE_BUSY In WAL Mode  ... If another database connection has the database mode open in exclusive locking mode then all queries against the database will return SQLITE_BUSY. Both Chrome and Firefox open their database files in exclusive locking mode, so attempts to read Chrome or ... 

 ... rc = sqlite3_open("file:memdb1?mode=memory&cache=shared", &db); Or, ATTACH DATABASE 'file:memdb1?mode=memory&cache=shared' AS aux1; When an in-memory database is named in this way, it will only share its cache with ... 

struct sqlite3_snapshot

An instance of the snapshot object records the state of a WAL mode database for some specific point in history. In WAL mode, multiple database connections that are open on the same database file can each be reading a different ... 

22.2. Command-line Options  ... Default '' -pagecache SIZE N use N slots of SZ bytes each for page cache memory -pcachetrace trace all page cache operations -quote set output mode to 'quote' -readonly open the database read-only -safe enable safe-mode -separator SEP set ... 

sqlite3_blob_close()

 ... If the blob handle being closed was opened for read-write access, and if the database is in auto-commit mode and there are no other open read-write blob handles or active write statements, the current transaction is committed ...