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Comment:Add documentation for new pragma "journal_size_limit".
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SHA1: f814d9bff559558ab946a116cbbf3098dd41f646
User & Date: dan 2008-06-05 17:03:04
Context
2008-06-10
12:59
Updates to the cintro.html page. check-in: 1e0484c51a user: drh tags: trunk
2008-06-05
17:03
Add documentation for new pragma "journal_size_limit". check-in: f814d9bff5 user: dan tags: trunk
2008-05-30
18:58
Added Shane's picture and biography to the maintainers page. check-in: c1fc3a9bee user: drh tags: trunk
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Changes to pages/pragma.in.

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    <p>The OFF journaling mode disables the rollback journal completely.
    No rollback journal is ever created and hence there is never a rollback
    journal to delete.  The OFF journaling mode disables the atomic
    commit and rollback capabilities of SQLite.  If a crash or power failure
    occurs in the middle of a transaction when the OFF journaling mode is
    set, then the database file will very likely go corrupt.</p>
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<tcl>Subsection legacy_file_format</tcl>
<li><p><b>PRAGMA legacy_file_format;
       <br>PRAGMA legacy_file_format = <i>ON | OFF</i></b></p>
    <p>This pragma sets or queries the value of the legacy_file_format
    flag.  When this flag is on, new SQLite databases are created in







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    <p>The OFF journaling mode disables the rollback journal completely.
    No rollback journal is ever created and hence there is never a rollback
    journal to delete.  The OFF journaling mode disables the atomic
    commit and rollback capabilities of SQLite.  If a crash or power failure
    occurs in the middle of a transaction when the OFF journaling mode is
    set, then the database file will very likely go corrupt.</p>
</li>

<tcl>Subsection journal_size_limit</tcl>
<li><p><b>
    PRAGMA &#91;database.&#93;journal_size_limit
    PRAGMA &#91;database.&#93;journal_size_limit = </b><i>N</i> <b>;</b>

  <p>If a database connection is operating in either "exclusive mode"
  (PRAGMA locking_mode=exclusive) or "persistent journal mode"
  (PRAGMA journal_mode=persist) then under certain circumstances
  after committing a transaction the journal file may remain in
  the file-system. This increases efficiency but also consumes
  space in the file-system. After a large transaction (e.g. a VACUUM),
  it may consume a very large amount of space.

  <p>This pragma may be used to limit the size of journal files left
  in the file-system after transactions are committed on a per database
  basis. Each time a transaction is committed, SQLite compares the
  size of the journal file left in the file-system to the size limit
  configured using this pragma. If the journal file is larger than the
  limit allows for, it is truncated to the limit.

  <p>The second form of the pragma listed above is used to set a new limit
  in bytes for the specified database. A negative number implies no limit.
  Both the first and second forms of the pragma listed above return a single
  result row containing a single integer column - the value of the journal
  size limit in bytes. The default limit value is -1 (no limit), which
  may be overridden by defining the preprocessor macro
  SQLITE_DEFAULT_JOURNAL_SIZE_LIMIT at compile time.

  <p>If no [database] is specified, the pragma operates on the main database.
  There is no way to operate on all attached databases using a single
  PRAGMA statement, nor is there a way to set the limit to use for databases
  that will be attached in the future.
</li>


<tcl>Subsection legacy_file_format</tcl>
<li><p><b>PRAGMA legacy_file_format;
       <br>PRAGMA legacy_file_format = <i>ON | OFF</i></b></p>
    <p>This pragma sets or queries the value of the legacy_file_format
    flag.  When this flag is on, new SQLite databases are created in