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The first 100 bytes of the database file comprise the database file header.
The database file header is divided into fields as shown by the table below.
All multibyte fields in the database file header are stored with the most significant byte first (big-endian).
gnificant byte first (big-endian).
Database Header Format
| Offset | Size | Description |
|---|---|---|
| 0 | 16 | The header string: “SQLite format 3\000” |
| 16 | 2 | The database page size in bytes. Must be a power of two between 512 and 32768 inclusive, or the value 1 representing a page size of 65536. |
| 18 | 1 | File format write version. 1 for legacy; 2 for WAL. |
| 19 | 1 | File format read version. 1 for legacy; 2 for WAL. |
| 20 | 1 | Bytes of unused “reserved” space at the end of each page. Usually 0. |
| 21 | 1 | Maximum embedded payload fraction. Must be 64. |
| 22 | 1 | Minimum embedded payload fraction. Must be 32. |
| 23 | 1 | Leaf payload fraction. Must be 32. |
| 24 | 4 | File change counter. |
| 28 | 4 | Size of the database file in pages. The “in-header database size”. |
| 32 | 4 | Page number of the first freelist trunk page. |
| 36 | 4 | Total number of freelist pages. |
| 40 | 4 | The schema cookie. |
| 44 | 4 | The schema format number. Supported schema formats are 1, 2, 3, and 4. |
| 48 | 4 | Default page cache size. |
| 52 | 4 | The page number of the largest root b-tree page when in auto-vacuum or incremental-vacuum modes, or zero otherwise. |
| 56 | 4 | The database text encoding. A value of 1 means UTF-8. A value of 2 means UTF-16le. A value of 3 means UTF-16be. |
| 60 | 4 | The “user version” as read and set by the user_version pragma. |
| 64 | 4 | True (non-zero) for incremental-vacuum mode. False (zero) otherwise. |
| 68 | 4 | The “Application ID” set by PRAGMA application_id. |
| 72 | 20 | Reserved for expansion. Must be zero. |
| 92 | 4 | The version-valid-for number. |
| 96 | 4 | SQLITE_VERSION_NUMBER |