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DbEnv::log_archive
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#include &lt;db_cxx.h&gt;

int
DbEnv::log_archive(char *(*listp)[], u_int32_t flags);
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Description: DbEnv::log_archive
The DbEnv::log_archive method returns an array of log or database filenames.
By default, DbEnv::log_archive returns the names of all of the log
files that are no longer in use (for example, that are no longer
involved in active transactions), and that may safely be archived for
catastrophic recovery and then removed from the system. If there are
no filenames to return, the memory location to which listp
refers will be set to NULL.
Arrays of log filenames are stored in allocated memory. If application-specific allocation
routines have been declared (see <a href="../../db4-devel-4.7.25/api_cxx/env_set_alloc.html">DbEnv::set_alloc</a> for more
information), they are used to allocate the memory; otherwise, the
standard C library malloc(3) is used. The caller is
responsible for deallocating the memory. To deallocate the memory, free
the memory reference; references inside the returned memory need not be
individually freed.
Log cursor handles (returned by the <a href="../../db4-devel-4.7.25/api_cxx/log_cursor.html">DbEnv::log_cursor</a> method) may have open
file descriptors for log files in the database environment. Also, the
Berkeley DB interfaces to the database environment logging subsystem (for
example, <a href="../../db4-devel-4.7.25/api_cxx/log_put.html">DbEnv::log_put</a> and <a href="../../db4-devel-4.7.25/api_cxx/txn_abort.html">DbTxn::abort</a>) may allocate log cursors
and have open file descriptors for log files as well. On operating
systems where filesystem related system calls (for example, rename and
unlink on Windows/NT) can fail if a process has an open file descriptor
for the affected file, attempting to move or remove the log files listed
by DbEnv::log_archive may fail. All Berkeley DB internal use of log cursors
operates on active log files only and furthermore, is short-lived in
nature. So, an application seeing such a failure should be restructured
to close any open log cursors it may have, and otherwise to retry the
operation until it succeeds. (Although the latter is not likely to be
necessary; it is hard to imagine a reason to move or rename a log file
in which transactions are being logged or aborted.)
See <a href="../../db4-utils-4.7.25/utility/db_archive.html">db_archive</a> for more information on database archival
procedures.
The DbEnv::log_archive method
either returns a non-zero error value
or throws an exception that encapsulates a non-zero error value on
failure, and returns 0 on success.

Parameters 
 flags<ul compact><li>The flags parameter must be set to 0 or by bitwise inclusively OR'ing together one
or more of the following values:
 
<a name="DB_ARCH_ABS">DB_ARCH_ABS</a><ul compact><li>All pathnames are returned as absolute pathnames, instead of relative
to the database home directory.</ul>
<a name="DB_ARCH_DATA">DB_ARCH_DATA</a><ul compact><li>Return the database files that need to be archived in order to recover
the database from catastrophic failure. If any of the database files
have not been accessed during the lifetime of the current log files,
DbEnv::log_archive will not include them in this list. It is also
possible that some of the files referred to by the log have since been
deleted from the system.
The DB_ARCH_DATA and DB_ARCH_LOG flags are mutually exclusive.</ul>
<a name="DB_ARCH_LOG">DB_ARCH_LOG</a><ul compact><li>Return all the log filenames, regardless of whether or not they are in
use.
The DB_ARCH_DATA and DB_ARCH_LOG flags are mutually exclusive.</ul>
<a name="DB_ARCH_REMOVE">DB_ARCH_REMOVE</a><ul compact><li>Remove log files that are no longer needed; no filenames are returned.
Automatic log file removal is likely to make catastrophic recovery
impossible.
The DB_ARCH_REMOVE flag may not be specified with any other
flag.</ul>
 </ul>
 listp<ul compact><li>The listp parameter references memory into which the allocated
array of log or database filenames is copied. If there are no filenames
to return, the memory location to which listp refers will be set
to NULL.</ul>
 
 Errors
The DbEnv::log_archive method
may fail and throw
<a href="../../db4-devel-4.7.25/api_cxx/except_class.html">DbException</a>,
encapsulating one of the following non-zero errors, or return one of
the following non-zero errors:
 
EINVAL<ul compact><li>An
invalid flag value or parameter was specified.</ul>
 
<hr size=1 noshade>
 Class
<a href="../../db4-devel-4.7.25/api_cxx/env_class.html">DbEnv</a>, <a href="../../db4-devel-4.7.25/api_cxx/logc_class.html">DbLogc</a>, <a href="../../db4-devel-4.7.25/api_cxx/lsn_class.html">DbLsn</a>
 See Also
<a href="../../db4-devel-4.7.25/api_cxx/log_list.html">Logging Subsystem and Related Methods</a>
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