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|Comment:||Fix typos on the wal.html page.|
|Downloads:||Tarball | ZIP archive | SQL archive|
|Timelines:||family | ancestors | descendants | both | trunk|
|Files:||files | file ages | folders|
|User & Date:||drh 2010-06-25 13:45:43|
|14:52||Add the ability to include TEA snapshots on the download page. (check-in: 2415d6de49 user: drh tags: trunk)|
|13:45||Fix typos on the wal.html page. (check-in: 3bf3e14239 user: drh tags: trunk)|
|17:51||Improve explanation of page_size limitations in WAL mode. Fix a broken link in fileformat2.in. (check-in: c079123bb9 user: drh tags: trunk)|
Changes to pages/wal.in.
58 58 revert the database file to its original state. The [COMMIT] occurs 59 59 when the rollback journal is deleted.</p> 60 60 61 61 <p>The WAL approach inverts this. The original content is preserved 62 62 in the database file and the changes are appended into a separate 63 63 WAL file. A [COMMIT] occurs when a special record indicating a commit 64 64 is appended to the WAL. Thus a COMMIT can happen without ever writing 65 -to the original database, which allows reader to continue operating 65 +to the original database, which allows readers to continue operating 66 66 from the original unaltered database while changes are simultaneously being 67 67 committed into the WAL. Multiple transactions can be appended to the 68 68 end of a single WAL file.</p> 69 69 70 70 <tcl>hd_fragment ckpt checkpoint checkpointed checkpointing</tcl> 71 71 <h3>Checkpointing</h3> 72 72 ................................................................................ 230 230 <p>The journal_mode pragma returns a string which is the new journal mode. 231 231 On success, the pragma will return the string "<tt>wal</tt>". If 232 232 the conversion to WAL could not be completed (for example, if the VFS 233 233 does not support the necessary shared-memory primitives) then the 234 234 journaling mode will be unchanged and the string returned from the 235 235 primitive will be the prior journaling mode (for example "<tt>delete</tt>"). 236 236 237 -<a name="how_to_checkpoint"> 237 +<a name="how_to_checkpoint"></a> 238 238 <p>By default, SQLite will automatically checkpoint whenever a [COMMIT] 239 239 occurs that causes the WAL file to be 1000 pages or more in size, or when the 240 240 last database connection on a database file closes. The default 241 241 configuration is intended to work well for most applications. 242 242 But programs that want more control can force a checkpoint 243 243 using the [wal_checkpoint pragma] or by calling the 244 244 [sqlite3_wal_checkpoint()] C interface. The automatic checkpoint