Designing a Multi-Table Schema for Episode and Artist Data The core issue revolves around importing a complex CSV file into an SQLite database while maintaining a normalized schema. The CSV file contains rows where each row represents an episode of a radio program, but the data is not in a straightforward one-row-per-record format. Instead, each…
Issue Overview: SQLite Tokenizer Rejects Vertical Tab as Leading Whitespace After Semicolon The core issue arises when a vertical tab character (\v, Unicode U+000B) is placed immediately after a semicolon (;) in SQL input. This configuration triggers a parse error in SQLite, even though other whitespace characters (e.g., form feed \f, space , or newline…
Issue Overview: Inconsistent Search Results with FTS5 Porter-Unicode61 Tokenizer in Polish Text A user reported unexpected behavior when querying Polish-language lyrics stored in an SQLite FTS5 virtual table configured with the tokenize="porter unicode61 remove_diacritics 2" option. Searches for terms like piecy* (intended to match words starting with "piecy") returned inconsistent results. For example, piecy* matched…
Understanding Column Type Shifts from REAL to NUMERIC in UNION ALL Operations Issue Overview: Column Affinity Determination in UNION ALL Contexts When utilizing UNION ALL operations in SQLite to combine results from multiple SELECT statements, the resulting column’s data type affinity may shift unexpectedly depending on the SQLite version or driver implementation. This behavior becomes…
Transaction Isolation and Statement Lifecycle in Concurrent SQLite WAL Environments Persistent Read Transactions Due to Unfinalized Prepared Statements The core issue arises when a database connection operating in Write-Ahead Logging (WAL) mode fails to observe committed changes from another connection due to an unfinalized or unresolved prepared statement. This behavior is rooted in SQLite’s transaction…
Issue Overview: FTS5Vocab Table Creation Fails with Combined Schema.Table Identifiers When creating a virtual table using the fts5vocab module in SQLite, the parser encounters issues when the schema and table names are combined into a single identifier using square brackets [] or backticks `. For example, [temp.foo3] or `temp.foo3` results in a parsing error, specifically…
Understanding the SQLite Database File Location and Structure on Android The core issue revolves around manually recovering SQLite data from an Android device where the screen is broken, rendering the app and its data-upload functionality inaccessible. The primary challenge is that the devices were not in USB debugging mode, which limits the options for direct…
Understanding SQLite WAL Mode and Deleted Database Behavior SQLite’s Write-Ahead Logging (WAL) mode is a powerful feature that enhances concurrency and performance by allowing multiple readers and a single writer to operate on the database simultaneously. However, this mode introduces unique behaviors that can be counterintuitive, especially when dealing with file operations like deleting or…
Issue Overview: Subquery UNION Filter Conditions Not Pushed Down to Constituent Queries When working with SQLite, developers often rely on the query optimizer to transform high-level SQL statements into efficient execution plans. A common expectation is that filters applied to the results of a subquery or view will be "pushed down" into the individual components…
Understanding SQLite Performance Challenges in High-Concurrency PHP Web Environments The core challenge revolves around optimizing SQLite database performance when deployed in a PHP-based web application serving high concurrent traffic. The specific use case involves a WordPress object cache plugin that handles numerous short-lived PHP processes (25+ concurrent instances) interacting with a SQLite database configured in…