Understanding Why SQLite’s Query Planner Avoids Composite Index for Multi-Value IN Clauses Issue Overview: Composite Index Ignored During Multi-Tuple IN Clause Queries When querying a SQLite table with a composite primary key (e.g., (id, time)), developers expect the query planner to leverage the index for efficient lookups. However, in scenarios where an IN clause contains…
Issue Overview: Performance Degradation in Index Usage with Function-Based Indexes and WHERE Clauses The core issue revolves around a performance degradation observed in SQLite when executing queries that involve function-based indexes combined with specific WHERE clause conditions. This degradation manifests as the query planner opting for a full table scan (SCAN) instead of utilizing the…
JSON Path Wildcard Limitations in SQLite’s json_extract Function Issue Overview The core issue revolves around the lack of wildcard support in SQLite’s json_extract function, specifically when attempting to extract values from nested JSON structures using a wildcard path. The json_extract function is a powerful tool in SQLite for querying JSON data, but it currently does…
Understanding Timestamp Stability in SQLite and PostgreSQL Core Issue: Step vs. Transaction Stability SQLite and PostgreSQL differ fundamentally in how they handle temporal functions like NOW(), CURRENT_TIMESTAMP, and datetime(‘now’). SQLite Behavior (Step Stability) The datetime(‘now’) function returns the exact same value for all calls within a single sqlite3_step() operation (i.e., during the execution of one…
Understanding the JDBC URL Path Discrepancy in SQLite Connections When working with SQLite databases in Java applications, establishing a correct and consistent database connection is crucial. A common issue arises when developers encounter discrepancies in the database connection behavior due to differences in the JDBC URL path formats. This problem often manifests when the application…
Understanding DuckDB 0.7’s SQLite Database Integration The integration of DuckDB 0.7 with SQLite databases introduces a novel hybrid architecture where DuckDB acts as a front-end query engine for SQLite database files. This capability allows users to attach SQLite databases to DuckDB sessions and execute analytical queries using DuckDB’s execution engine while reading/writing data stored in…
WebSQL to SQLite/OPFS Migration: Performance Degradation and Transaction Management Issue Overview The core issue revolves around migrating data from WebSQL, a deprecated web-based SQL database, to SQLite running on the Origin Private File System (OPFS) in a WebAssembly (WASM) environment. The migration process involves transferring over 1 million rows of data from WebSQL, which operates…
Understanding Python’s SQLite Dependency Chain in Cygwin Issue Overview The core challenge involves ensuring that Python’s sqlite3 module within Cygwin uses a specific version of the SQLite shared library. By default, Python dynamically links to the SQLite library available in the system’s library paths. In Cygwin, Python packages are often compiled against the SQLite version…
ZIP Archive Size Exceeds SQLite zipfile’s 32-Bit Integer Limits The SQLite zipfile virtual table allows querying ZIP archives as if they were database tables. However, users encounter unexpected behavior when querying large ZIP files (e.g., 6GB) with this feature. Executing basic queries like SELECT COUNT(*) FROM zip or SELECT name FROM zip LIMIT 1 returns…
The Absence of a Native SQLite Connector in Power Query The core issue revolves around the lack of a native SQLite connector in Power Query, a data transformation and connectivity tool widely used in Microsoft Excel and Power BI. Power Query supports a variety of data sources, including databases like MySQL, PostgreSQL, and Oracle, as…