Understanding the Behavior of RETURNING rowid in Virtual Table INSERTs When working with SQLite virtual tables, one of the most common tasks is inserting data and retrieving the automatically generated rowid. The rowid is a unique identifier for each row in a table, and it is often used for efficient lookups and updates. However, a…
SQLite as a Transferable Document Format: Security and Practical Considerations SQLite is often touted as a versatile and lightweight database engine, suitable for a wide range of applications, including serving as an application file format. However, when considering its use as a transferable document format—particularly for untrusted files—several security and practical concerns arise. This post…
Understanding the Performance Impact of Primary Key Scans in Rowid Tables The core issue revolves around unexpectedly slow performance when executing a SELECT query that orders results by a TEXT primary key in a large SQLite table (7 million rows, ~5GB). The schema defines the primary key as key TEXT PRIMARY KEY, which implicitly creates…
Performance Degradation of Floating-Point Queries on ARM Architecture The core issue revolves around a significant performance degradation observed when executing queries involving floating-point numbers on ARM architecture after upgrading SQLite from version 3.28 to 3.46.1. The problem manifests specifically in the sqlite3_str_vappendf function, which is responsible for formatting and appending strings, particularly when handling floating-point…
Issue Overview: Malware Scanners Interfering With SQLite File Access Malware scanners and antivirus software can interfere with SQLite database operations through file locking conflicts. These conflicts manifest when the scanner attempts to read or scan the database file while an application is actively using it via SQLite’s API. SQLite employs file locking mechanisms to ensure…
Schema Design Flaws Leading to Foreign Key Mismatch Errors Issue Overview: Unexpected Foreign Key Mismatch During Updates The core issue arises when attempting to update a row in the users table, even when the updated row has no direct or indirect references in child tables like team_members. The error message foreign key mismatch – "team_members"…
Understanding the Performance Regression in SQLite 3.47.2 The core issue revolves around a significant performance degradation observed when executing queries on a complex schema in SQLite 3.47.2 compared to SQLite 3.46.1. The schema in question involves a highly intricate design with numerous views, unions, joins, window functions, and aggregations. While the schema was performant in…
Understanding SQLite’s Non-Thread-Safe Build in Single-Threaded Coroutine Environments Issue Overview: Coroutine Safety in SQLite Without Mutexes The core issue revolves around using SQLite in a single-threaded, multi-coroutine environment where the SQLite library is compiled without thread safety (i.e., SQLITE_THREADSAFE=0 or -DSQLITE_THREADSAFE=0). In this setup, multiple coroutines operate within the same thread, each managing its own…
Understanding SQLite Database Creation Mechanics and Multi-DB Workflows Issue Overview The core challenge revolves around creating additional SQLite databases programmatically while maintaining an active connection to an initial database. Users familiar with client-server database systems like MySQL or PostgreSQL often expect a CREATE DATABASE SQL command to instantiate new databases. However, SQLite’s architecture treats each…
Understanding the Need for Ordered NEAR Queries in Hierarchical Data The core issue revolves around the need to enforce a specific order in Full Text Search (FTS) NEAR queries, particularly when dealing with hierarchical data structures. In this scenario, the data represents a tree-like structure where objects have attributes and classes, and the relationships between…