Author: SQLite.work Team

Understanding the Assertion Failures in codeWithoutRowidPreupdate and btreeInitPage The core issue revolves around two assertion failures in SQLite: one in the codeWithoutRowidPreupdate function and another in the btreeInitPage function. These assertions are triggered during specific operations involving table creation, schema manipulation, and vacuuming. The errors suggest that the database may be in a corrupted state…

Crash Context: Schema Initialization & decodeIntArray Memory Access Violation The segmentation fault occurs during SQLite’s schema initialization process when attempting to decode integer array data stored in the SQLITE_STAT4 table. The crash manifests in the decodeIntArray() function due to an invalid memory write operation at address 0x000000000001, indicating a null pointer dereference or buffer overflow….

Understanding the UPSERT Parse Error with Composite UNIQUE Constraints Issue Overview The core problem arises when attempting an INSERT … ON CONFLICT (UPSERT) operation targeting a composite UNIQUE constraint in SQLite. The operation fails with a parse error: Parse error: ON CONFLICT clause does not match any PRIMARY KEY or UNIQUE constraint This error occurs…

Segmentation Fault in shell_dbinfo_command Function Under Low Memory Conditions The segmentation fault in the shell_dbinfo_command function is a critical issue that arises when SQLite is operating under low memory conditions. This fault occurs during the execution of specific queries, particularly when the PRAGMA hard_heap_limit is set to a restrictive value, and certain commands like .dbi…

Understanding the Assertion Failures in SQLite’s Parser The core issue revolves around assertion failures in SQLite’s yy_reduce function, a critical component of the SQLite parser. These failures occur under specific conditions, often involving memory constraints, syntax errors, or invalid SQL statements. The failures manifest as crashes, segmentation faults, or undefined behavior, making them particularly challenging…

Understanding Cross-Origin Isolation Requirements for SQLite WASM and CDN Conflicts The Core Challenge: Cross-Origin Isolation vs. Mixed-Origin Resource Loading To use SQLite’s WebAssembly (WASM) module with the Origin Private File System (OPFS) persistence layer, browsers require Cross-Origin Isolation. This security measure is enforced via the Cross-Origin-Opener-Policy (COOP) and Cross-Origin-Embedder-Policy (COEP) HTTP headers. When these headers…

SQLite Single-Thread Mode: Key Concepts and Limitations SQLite is a lightweight, serverless, and self-contained database engine that is widely used in embedded systems, mobile applications, and desktop software. One of its defining features is its flexibility in threading modes, which allows developers to configure SQLite for different concurrency requirements. However, this flexibility also introduces complexity,…