SQLite Database Size Limitation with max_page_count When working with SQLite, one of the key features that developers often leverage is the ability to limit the size of a database file using the max_page_count pragma. This pragma allows you to set a maximum number of pages that the database can contain, effectively capping the size of…
SQLite WAL and SHM Files Persisting After Database Closure When working with SQLite databases in Write-Ahead Logging (WAL) mode, it is common to encounter two auxiliary files: the -wal (Write-Ahead Log) file and the -shm (Shared Memory) file. These files are integral to the WAL mechanism, which enhances concurrency and performance by allowing multiple readers…
Unexpected Full Scan of table_two When Using a Filtered View When working with SQLite, one common performance issue arises when the query planner generates an unexpected execution plan, particularly when views and LEFT JOINs are involved. In this scenario, a view named table_two_filter is created to filter rows from table_two where the flag column equals…
Parameterized Script Execution in SQLite: A Missing Oracle-like Feature SQLite, while being a lightweight and powerful database engine, lacks some of the convenience features found in more heavyweight databases like Oracle. One such feature is the ability to execute parameterized scripts directly within the SQLite shell, similar to Oracle’s SQL*Plus @count employee department syntax. This…
GCC-10 Warning: Function May Return Address of Local Variable in sqlite3SelectNew The sqlite3SelectNew function in SQLite is a critical component responsible for allocating and initializing a new Select structure, which is used to represent SQL SELECT statements during query parsing. However, when compiling SQLite with GCC-10, a specific warning arises: warning: function may return address…
SQLite Recursive Triggers Default Setting Mismatch Between Documentation and Code The core issue revolves around a discrepancy between the SQLite documentation and the actual implementation in the source code regarding the default setting for recursive triggers. According to the SQLite documentation, recursive triggers have been enabled by default since version 3.7.0, which was released on…
SQLite’s Lack of Centralized Change Tracking Mechanism SQLite, unlike client-server database systems such as MSSQL, does not have a centralized server process that handles all database operations. This architectural difference means that there is no single point of control or monitoring that can track all changes made to the database by various clients. In MSSQL,…
Understanding SQLite Binaries and Installation Process SQLite is a lightweight, serverless, self-contained SQL database engine that is widely used in applications ranging from embedded systems to web browsers. Unlike traditional database management systems, SQLite does not require a separate server process and stores the entire database as a single file. This simplicity makes it an…
BLOB Overflow Page Rewrites During Non-Binary Column Updates When working with SQLite databases, particularly those containing large binary objects (BLOBs), a common issue arises when updating non-binary columns in a table that also contains BLOBs. Specifically, setting non-binary columns to NULL in such tables can lead to unexpected database file size growth. This behavior is…
Space-Separated Fields in SELECT Statements: A Silent Syntax Quirk When writing SQL queries, particularly in SQLite, it is not uncommon to encounter subtle syntax behaviors that can lead to unexpected results. One such behavior involves the use of space-separated fields in the SELECT statement. For instance, consider the following query: SELECT Field1, Field2 Field3, Field4…