{"record":{"id":"d545ed7df0678594","repo":"transact-rs/sqlx","slug":"sqlite-is-unable-to-allocate-memory-to-hold-the-sq","errorCode":null,"errorMessage":"SQLite is unable to allocate memory to hold the sqlite3 object","messagePattern":"SQLite is unable to allocate memory to hold the sqlite3 object","errorType":"exception","errorClass":"io::Error (OutOfMemory)","httpStatus":null,"severity":"critical","filePath":"sqlx-sqlite/src/connection/handle.rs","lineNumber":38,"sourceCode":"// enabled and [SQLITE_THREADSAFE] was enabled when sqlite was compiled. We refuse to work\n// if these conditions are not upheld.\n//\n// <https://www.sqlite.org/c3ref/threadsafe.html>\n// <https://www.sqlite.org/c3ref/c_config_covering_index_scan.html#sqliteconfigmultithread>\n\nunsafe impl Send for ConnectionHandle {}\n\nimpl ConnectionHandle {\n    pub(crate) fn open(filename: &CStr, flags: c_int) -> Result<Self, Error> {\n        let mut handle = ptr::null_mut();\n\n        // <https://www.sqlite.org/c3ref/open.html>\n        let status = unsafe { sqlite3_open_v2(filename.as_ptr(), &mut handle, flags, ptr::null()) };\n\n        // SAFETY: the database is still initialized as long as the pointer is not `NULL`.\n        // We need to close it even if there's an error.\n        let mut handle = Self(NonNull::new(handle).ok_or_else(|| {\n            Error::Io(io::Error::new(\n                io::ErrorKind::OutOfMemory,\n                \"SQLite is unable to allocate memory to hold the sqlite3 object\",\n            ))\n        })?);\n\n        if status != SQLITE_OK {\n            return Err(Error::Database(Box::new(handle.expect_error())));\n        }\n\n        // Enable extended result codes\n        // https://www.sqlite.org/c3ref/extended_result_codes.html\n        unsafe {\n            // This only returns a non-OK code if SQLite is built with `SQLITE_ENABLE_API_ARMOR`\n            // and the database pointer is `NULL` or already closed.\n            //\n            // The invariants of this type guarantee that neither is true.\n            sqlite3_extended_result_codes(handle.as_ptr(), 1);\n        }","sourceCodeStart":20,"sourceCodeEnd":56,"githubUrl":"https://github.com/transact-rs/sqlx/blob/03af8bcc5711a1935580a54bea249c219a0c217d/sqlx-sqlite/src/connection/handle.rs#L20-L56","documentation":"`sqlite3_open_v2` returned success-path memory that is `NULL`, meaning SQLite could not allocate the `sqlite3` handle object. sqlx checks this even when the returned status might otherwise look plausible, and raises an `OutOfMemory` I/O error, closing the (uninitialized) handle path immediately.","triggerScenarios":"Opening any SQLite connection (`SqliteConnection::connect`, pools, `AnyDriver` backed by SQLite) when the process is out of memory or address space, or under extreme resource limits (ulimit, cgroup memory cap, containers with tight memory).","commonSituations":"Memory-constrained Docker/Kubernetes pods, CI runners with tiny RAM limits, memory leaks elsewhere in a long-lived process exhausting the heap before opening a new connection pool.","solutions":["Free memory in the process (drop caches/pools, fix leaks) and retry the connection.","Raise the memory limit of the container/process (K8s memory limit, `ulimit -v`, JVM/other runtime heap caps).","Reduce connection pool size (`max_connections`) so concurrent opens fit in available memory.","If persistent, restart the process/host — this indicates the allocator could not satisfy a small allocation."],"exampleFix":"// before\nlet pool = Pool::connect_with(\n    SqliteConnectOptions::new().filename(\"app.db\")\n).await?; // OOM under tight memory limits with max pool opens\n\n// after\nlet pool = Pool::builder(\n    SqliteConnectOptions::new().filename(\"app.db\")\n)\n.max_connections(2)\n.build()\n.await?;","handlingStrategy":"retry","validationCode":"fn can_attempt_db_open() -> bool {\n    // cheap heuristic: skip the attempt when the system is under severe memory pressure\n    !std::path::Path::new(\"/proc/meminfo\").exists()\n        || std::fs::read_to_string(\"/proc/meminfo\")\n            .map(|s| !s.contains(\"MemAvailable:          0 kB\"))\n            .unwrap_or(true)\n}","typeGuard":"// Rust has no runtime type to narrow for a failed allocation;\n// model capacity instead.\nfn pool_config_is_sane(max_connections: u32) -> bool {\n    max_connections > 0 && max_connections <= 64\n}","tryCatchPattern":"// no exceptions in Rust; wrap connection setup so OOM is not fatal to the process\nlet pool = std::panic::catch_unwind(|| {\n    tokio::runtime::Handle::current().block_on(\n        Pool::connect_with(opts.clone())\n    )\n});\nmatch pool {\n    Ok(Ok(p)) => p,\n    _ => { free_resources(); retry_with_backoff(); }\n}","preventionTips":["Set pool `max_connections` well below what the container memory limit can sustain.","Monitor memory (RSS/cgroup usage) and alert before hitting limits.","Fix heap leaks in long-lived processes; cycle workers periodically.","Avoid opening new pools in hot paths; reuse a single shared pool."],"tags":["rust","sqlx","sqlite","out-of-memory","resource-limits"],"backgroundTag":"out-of-memory","analyzedSha":"03af8bcc5711a1935580a54bea249c219a0c217d","analyzedAt":"2026-09-03T15:01:28.752Z","contentChangedAt":"2026-09-03T15:01:28.752Z","schemaVersion":2},"datasetVersion":"2026-09-10T17:17:09.494Z"}