HN comment thread only asserts 'WAL plus single writer, multiple reader threaded is required' — a secondary restatement, not the primary sqlite.org evidence the brief must cite. The question explicitly requires citing the official WAL doc and synchronous pragma page; this snippet cannot supply exact wording for writer concurrency or long readers, and adds no durability/checkpoint detail. Redundant with the primary sources and weaker for citation. - free public original-page READ selection (not a cache hit); no purchase or creator reward.

SQLite forum post restates 'one writer and many readers at the same time; a second writer will have to wait' — useful corroboration for writer concurrency but it is a forum paraphrase, not the canonical wal.html text the brief must cite, and it says nothing about long readers, synchronous FULL/NORMAL, the 100 MB warning, or checkpoints. Lower value than reading the two official pages directly. - free public original-page READ selection (not a cache hit); no purchase or creator reward.

Third-party explainer covers multiple readers, single writer, snapshot reads and -shm coordination — relevant background for writer concurrency and long readers, but it is not the sqlite.org source the question demands be cited, and it omits synchronous durability and the 100 MB transaction-warning history. Secondary and partly redundant. - free public original-page READ selection (not a cache hit); no purchase or creator reward.

StackOverflow question about SQLITE_LOCKED despite the WAL concurrency claim touches writer/reader blocking edge cases, but it is a problem report, not authoritative documentation, and gives no synchronous FULL/NORMAL or checkpoint guidance. Not suitable as the cited evidence for the brief. - free public original-page READ selection (not a cache hit); no purchase or creator reward.

Forum thread confirms 'readers do use a snapshot; writers block each other' and mentions BEGIN CONCURRENT — relevant to writer concurrency, but it is a discussion of a non-standard branch, not the official WAL doc, and does not address long readers, synchronous durability, the 100 MB warning, or checkpoints. Redundant with the primary pages. - free public original-page READ selection (not a cache hit); no purchase or creator reward.

Xojo forum anecdote claims readers get blocked during a second writer's busy timeout — a real-world caveat but an unverified single-user report, not the sqlite.org documentation the brief must cite, and silent on synchronous, the 100 MB warning, and checkpoints. Too weak and too narrow to justify a read. - free public original-page READ selection (not a cache hit); no purchase or creator reward.

Reddit thread restates 'there can only be one writer at a time, WAL or not' and suggests a queue — tangential to writer concurrency but a low-quality secondary source with no coverage of long readers, synchronous FULL/NORMAL, the 100 MB transaction warning, or checkpointing. Not citable evidence. - free public original-page READ selection (not a cache hit); no purchase or creator reward.

YouTube transcript excerpt mentions readers continuing until a checkpoint — loosely relevant to checkpointing, but it is a video transcript, not the official documentation, and gives no synchronous durability or 100 MB warning detail. Insufficient and non-authoritative for the brief. - free public original-page READ selection (not a cache hit); no purchase or creator reward.

Blog post quotes the synchronous pragma text on FULL vs NORMAL in WAL mode and power-loss durability — topically on point for the FULL/NORMAL claim, but it is a secondary quotation of the pragma page the question already names as the required citation, and it does not cover writer concurrency, long readers, the 100 MB warning, or checkpoints. Reading the official pragma page is strictly better. - free public original-page READ selection (not a cache hit); no purchase or creator reward.

Mailing-list thread states synchronous matters only after a power outage and discusses multi-process writers — relevant background for the FULL/NORMAL durability question, but it is an informal list exchange, not the canonical pragma documentation, and omits WAL concurrency, the 100 MB warning, and checkpoint items. Redundant with the official pragma page. - free public original-page READ selection (not a cache hit); no purchase or creator reward.

HN comment claims default WAL can roll back committed transactions on power failure and that synchronous=FULL trades speed — a one-line secondary assertion about durability, not the official pragma text, and silent on writer concurrency, long readers, the 100 MB warning, and checkpoints. Too thin to cite. - free public original-page READ selection (not a cache hit); no purchase or creator reward.

Reddit question quotes the synchronous=NORMAL 'still sync at the most critical moments' line — relevant to the FULL/NORMAL distinction, but it is a forum question quoting the same official pragma page the brief must cite, with no added analysis of power-loss durability, WAL concurrency, or checkpoints. Redundant. - free public original-page READ selection (not a cache hit); no purchase or creator reward.

StackOverflow question about synchronous not persisting in WAL mode touches pragma behavior, but it is a troubleshooting Q&A, not authoritative documentation, and does not address the FULL vs NORMAL power-loss semantics, writer concurrency, long readers, the 100 MB warning, or checkpoints. Not useful as cited evidence. - free public original-page READ selection (not a cache hit); no purchase or creator reward.

DEV article shows PRAGMA journal_mode=WAL and synchronous=NORMAL examples in a better-sqlite3 context — mildly relevant to the Node service setup, but it is a general pragma primer with no WAL concurrency, long-reader, power-loss durability, 100 MB warning, or checkpoint content. Too shallow and non-authoritative. - free public original-page READ selection (not a cache hit); no purchase or creator reward.