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749 строки
35 KiB
HTML
<HTML>
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<HEAD>
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<TITLE>DbLog</TITLE>
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</HEAD>
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<BODY BGCOLOR=white>
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<H1>DbLog</H1>
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<HR SIZE=1 NOSHADE>
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<PRE>
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<!-- Manpage converted by man2html 3.0.1 -->
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<B>import</B> <B>com.sleepycat.db.*;</B>
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<B>public</B> <B>static</B> <B>DbLog</B> <B>open(String</B> <B>dir,</B> <B>int</B> <B>flags,</B> <B>int</B> <B>mode,</B> <B>DbEnv</B> <B>dbenv)</B>
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<B>throws</B> <B>DbException;</B>
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<B>public</B> <B>void</B> <B>close()</B>
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<B>throws</B> <B>DbException;</B>
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<B>public</B> <B>static</B> <B>int</B> <B>compare(DbLsn</B> <B>lsn0,</B> <B>DbLsn</B> <B>lsn1);</B>
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<B>public</B> <B>String</B> <B>file(DbLsn</B> <B>lsn)</B>
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<B>throws</B> <B>DbException;</B>
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<B>public</B> <B>void</B> <B>flush(DbLsn</B> <B>lsn)</B>
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<B>throws</B> <B>DbException;</B>
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<B>public</B> <B>void</B> <B>get(DbLsn</B> <B>lsn,</B> <B>Dbt</B> <B>data,</B> <B>int</B> <B>flags)</B>
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<B>throws</B> <B>DbException;</B>
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<B>public</B> <B>void</B> <B>put(DbLsn</B> <B>lsn,</B> <B>Dbt</B> <B>data,</B> <B>int</B> <B>flags)</B>
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<B>throws</B> <B>DbException;</B>
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<B>public</B> <B>DbLogStat</B> <B>stat()</B>
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<B>throws</B> <B>DbException;</B>
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<B>public</B> <B>int</B> <B>db</B>_<B>register(Db</B> <B>dbp,</B> <B>String</B> <B>name,</B> <B>int</B> <B>dbtype)</B>
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<B>throws</B> <B>DbException;</B>
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<B>public</B> <B>void</B> <B>db</B>_<B>unregister(int</B> <B>fid)</B>
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<B>throws</B> <B>DbException;</B>
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<B>public</B> <B>static</B> <B>void</B> <B>unlink(String</B> <B>dir,</B> <B>int</B> <B>force,</B> <B>DbEnv</B> <B>dbenv)</B>
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<B>throws</B> <B>DbException;</B>
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</PRE>
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<H2>DESCRIPTION</H2><PRE>
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The DB library is a family of classes that provides a
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modular programming interface to transactions and record-
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oriented file access. The library includes support for
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transactions, locking, logging and file page caching, as
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well as various indexed access methods. Many of the
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classes (e.g., the file page caching class) are useful
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independent of the other DB classes, although some classes
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are explicitly based on other classes (e.g., transactions
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and logging). For a general description of the DB
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package, see <B><A HREF="db_intro.html">db_intro(3)</A></B>.
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This manual page describes the specific details of the log
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class.
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This class provide a general-purpose logging facility
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sufficient for transaction management. Logs can be shared
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by multiple processes.
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The DB transaction log is represented by a directory
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containing a set of files. The log is a record-oriented,
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append-only file, with records identified and accessed via
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DbLsn's (database log sequence numbers).
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DbLsn's are returned on each DbLog.put operation, and only
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those DbLsn's returned by DbLog.put can later be used to
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retrieve records from the log.
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DbLog.open
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The DbLog.open method returns a log identified by the
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<B>directory</B> dir.
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If the dbenv argument to DbLog.open was initialized using
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DbEnv.appinit, dir is interpreted as described by
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<B><A HREF="DbEnv.j.html">DbEnv(3)</A></B>.
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Otherwise, if dir is not null, it is interpreted relative
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to the current working directory of the process. If dir
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is null, the following environment variables are checked
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in order: ``TMPDIR'', ``TEMP'', and ``TMP''. If one of
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them is set, log files are created relative to the
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directory it specifies. If none of them are set, the
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first possible one of the following directories is used:
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/var/tmp, /usr/tmp, /temp, /tmp, C:/temp and C:/tmp.
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All files associated with the log are created in this
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directory. This directory must already exist when
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DbLog.open is called. If the log already exists, the
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process must have permission to read and write the
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existing files. If the log does not already exist, it is
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optionally created and initialized.
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If the log region is being created and log files are
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already present, the log files are ``recovered'' and
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subsequent log writes are appended to the end of the log.
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The log is stored in one or more files in the specified
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directory. Each file is named using the format
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log.NNNNN
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where ``NNNNN'' is the sequence number of the file within
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the log.
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The flags and mode arguments specify how files will be
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opened and/or created when they don't already exist. The
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flags value is specified by <B>or</B>'ing together one or more of
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the following values:
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Db.DB_CREATE
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Create any underlying files, as necessary. If the
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files do not already exist and the DB_CREATE flag is
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not specified, the call will fail.
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Db.DB_THREAD
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Cause the DbLog handle returned by the DbLog.open
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method to be useable by multiple threads within a
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single address space, i.e., to be ``free-threaded''.
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Threading is assumed in the Java API, so no special
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flags are required, and DB functions will always
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behave as if the DB_THREAD flag was specified.
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All files created by the log subsystem are created with
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mode mode (as described in <B>chmod(2)</B>) and modified by the
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process' umask value at the time of creation (see
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<B>umask(2)</B>). The group ownership of created files is based
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on the system and directory defaults, and is not further
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specified by DB.
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The logging subsystem is configured based on which set
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methods have been used. It is expected that applications
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will use a single DbEnv object as the argument to all of
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the subsystems in the DB package. The fields of the DbEnv
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object used by DbLog.open are described below. As
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references to the DbEnv object may be maintained by
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DbLog.open, it is necessary that the DbEnv object and
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memory it references be valid until the object is
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destroyed. Any of the DbEnv fields that are not
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explicitly set will default to appropriate values.
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The following fields in the DbEnv object may be
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initialized, using the appropriate set method, before
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calling DbLog.open:
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DbErrcall db_errcall;
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String db_errpfx;
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int db_verbose;
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The error fields of the DbEnv behave as described for
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<B><A HREF="DbEnv.j.html">DbEnv(3)</A></B>. void *(*db_errcall)(char *db_errpfx, char
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*buffer);
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FILE *db_errfile;
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const char *db_errpfx;
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int db_verbose;
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The error fields of the DB_ENV behave as described
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for <B><A HREF="db_appinit.html">db_appinit(3)</A></B>.
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int lg_max;
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The maximum size of a single file in the log.
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Because DbLsn file offsets are unsigned 4-byte
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values, lg_max may not be larger than the maximum
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unsigned 4-byte value.
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If lg_max is 0, a default value is used.
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See the section "LOG FILE LIMITS" below, for further
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information.
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The DbLog.open method throws a <B><A HREF="DbException.j.html">DbException(3)</A></B> that
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encapsulates an errno on failure.
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DbLog.close
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The DbLog.close method closes the log associated with the
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DbLog object.
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In addition, if the dir argument to DbLog.open was null
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and dbenv was not initialized using DbEnv.appinit, all
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files created for this shared region will be removed, as
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if DbLog.unlink were called.
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When multiple threads are using the DbLog handle
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concurrently, only a single thread may call the
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DbLog.close method.
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The DbLog.close method throws a <B><A HREF="DbException.j.html">DbException(3)</A></B> that
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encapsulates an errno on failure.
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DbLog.flush
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The DbLog.flush method guarantees that all log records
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whose DbLsns are less than or equal to the lsn parameter
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have been written to disk. If lsn is null, all records in
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the log are flushed.
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The DbLog.flush method throws a <B><A HREF="DbException.j.html">DbException(3)</A></B> that
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encapsulates an errno on failure.
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DbLog.get
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The DbLog.get method implements a cursor inside of the
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log, retrieving records from the log according to the lsn
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and flags parameters.
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The data field of the data object is set to the record
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retrieved and the size field indicates the number of bytes
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in the record. See <B><A HREF="Dbt.j.html">Dbt(3)</A></B> for a description of other
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fields in the data object. <B>When</B> <B>multiple</B> <B>threads</B> <B>are</B>
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<B>using</B> <B>the</B> <B>returned</B> <B>DbLog</B> <B>handle</B> <B>concurrently,</B> <B>either</B> <B>the</B>
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<B>DB</B>_<B>DBT</B>_<B>MALLOC</B> <B>or</B> <B>DB</B>_<B>DBT</B>_<B>USERMEM</B> <B>flags</B> <B>must</B> <B>be</B> <B>specified</B>
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<B>for</B> <B>any</B> <B>Dbt</B> <B>used</B> <B>for</B> <B>data</B> <B>retrieval.</B>
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The flags parameter must be set to exactly one of the
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following values:
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Db.DB_CHECKPOINT
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The last record written with the DB_CHECKPOINT flag
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specified to the DbLog.put method is returned in the
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data argument. The lsn argument is overwritten with
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the DbLsn of the record returned. If no record has
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been previously written with the DB_CHECKPOINT flag
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specified, the first record in the log is returned.
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If the log is empty the DbLog.get method will return
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DB_NOTFOUND.
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Db.DB_FIRST
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The first record from any of the log files found in
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the log directory is returned in the data argument.
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The lsn argument is overwritten with the DbLsn of the
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record returned.
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If the log is empty the DbLog.get method will return
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DB_NOTFOUND.
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Db.DB_LAST
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The last record in the log is returned in the data
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argument. The lsn argument is overwritten with the
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DbLsn of the record returned.
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If the log is empty, the DbLog.get method will return
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DB_NOTFOUND.
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Db.DB_NEXT
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The current log position is advanced to the next
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record in the log and that record is returned in the
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data argument. The lsn argument is overwritten with
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the DbLsn of the record returned.
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If the pointer has not been initialized via DB_FIRST,
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DB_LAST, DB_SET, DB_NEXT, or DB_PREV, DbLog.get will
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return the first record in the log. If the last log
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record has already been returned or the log is empty,
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the DbLog.get method will return DB_NOTFOUND.
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If the log was opened with the DB_THREAD flag set,
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calls to DbLog.get with the DB_NEXT flag set will
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return EINVAL.
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Db.DB_PREV
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The current log position is moved to the previous
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record in the log and that record is returned in the
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data argument. The lsn argument is overwritten with
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the DbLsn of the record returned.
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If the pointer has not been initialized via DB_FIRST,
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DB_LAST, DB_SET, DB_NEXT, or DB_PREV, DbLog.get will
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return the last record in the log. If the first log
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record has already been returned or the log is empty,
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the DbLog.get method will return DB_NOTFOUND.
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If the log was opened with the DB_THREAD flag set,
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calls to DbLog.get with the DB_PREV flag set will
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return EINVAL.
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Db.DB_CURRENT
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Return the log record currently referenced by the
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log.
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If the log pointer has not been initialized via
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DB_FIRST, DB_LAST, DB_SET, DB_NEXT, or DB_PREV, or if
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the log was opened with the DB_THREAD flag set,
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DbLog.get will return EINVAL.
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Db.DB_SET
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Retrieve the record specified by the lsn argument.
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If the specified DbLsn is invalid (e.g., does not
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appear in the log) DbLog.get will return EINVAL.
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Otherwise, the DbLog.get method throws a <B><A HREF="DbException.j.html">DbException(3)</A></B>
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that encapsulates an errno on failure,
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DbLog.compare
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The DbLog.compare method allows the caller to compare two
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DbLsn's. DbLog.compare returns 0 if the two DbLsn's are
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equal, 1 if lsn0 is greater than lsn1, and -1 if lsn0 is
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less than lsn1.
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DbLog.file
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The DbLog.file method maps DbLsn's to file names. The
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DbLog.file method returns the name of the file containing
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the record named by lsn. (This mapping of DbLsn to file
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is needed for database administration. For example, a
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transaction manager typically records the earliest DbLsn
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needed for restart, and the database administrator may
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want to archive log files to tape when they contain only
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DbLsn's before the earliest one needed for restart.)
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The DbLog.file method throws a <B><A HREF="DbException.j.html">DbException(3)</A></B> that
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encapsulates an errno on failure.
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DbLog.put
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The DbLog.put method appends records to the log. The
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DbLsn of the put record is returned in the lsn parameter.
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The flags parameter may be set to one of the following
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values:
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Db.DB_CHECKPOINT
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The log should write a checkpoint record, recording
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any information necessary to make the log structures
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recoverable after a crash.
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Db.DB_CURLSN
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The DB_LSN of the next record to be put is returned
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in the lsn parameter.
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Db.DB_FLUSH
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The log is forced to disk after this record is
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written, guaranteeing that all records with DbLsns
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less than or equal to the one being put are on disk
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before this method returns (this function is most
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often used for a transaction commit, see Db.Txn in Db
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(3)).
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The caller is responsible for providing any necessary
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structure to data. (For example, in a write-ahead logging
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protocol, the application must understand what part of
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data is an operation code, what part is redo information,
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and what part is undo information. In addition, most
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transaction managers will store in data the DbLsn of the
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previous log record for the same transaction, to support
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chaining back through the transaction's log records during
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undo.)
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The DbLog.put method throws a <B><A HREF="DbException.j.html">DbException(3)</A></B> that
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encapsulates an errno on failure.
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DbLog.unlink
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The DbLog.unlink method destroys the log region identified
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by the directory dir, removing all files used to implement
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the log region. (The directory dir is not removed.) If
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there are processes that have called DbLog.open without
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calling DbLog.close (i.e., there are processes currently
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using the log region), DbLog.unlink will fail without
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further action, unless the force flag is set, in which
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case DbLog.unlink will attempt to remove the log region
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files regardless of any processes still using the log
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region.
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The result of attempting to forcibly destroy the region
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when a process has the region open is unspecified.
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Processes using a shared memory region maintain an open
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file descriptor for it. On UNIX systems, the region
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removal should succeed and processes that have already
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joined the region should continue to run in the region
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without change, however processes attempting to join the
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log region will either fail or attempt to create a new
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region. On other systems, e.g., WNT, where the <B>unlink(2)</B>
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system call will fail if any process has an open file
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descriptor for the file, the region removal will fail.
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In the case of catastrophic or system failure, database
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recovery must be performed (see <B><A HREF="db_recover.html">db_recover(1)</A></B> or the
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DB_RECOVER and DB_RECOVER_FATAL flags to
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<B><A HREF="DbEnv.j.html">DbEnv.appinit(3)</A></B>). Alternatively, if recovery is not
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required because no database state is maintained across
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failures, it is possible to clean up a log region by
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removing all of the files in the directory specified to
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the DbLog.open method, as log region files are never
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created in any directory other than the one specified to
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DbLog.open. Note, however, that this has the potential to
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remove files created by the other DB subsystems in this
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database environment.
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The DbLog.unlink method throws a <B><A HREF="DbException.j.html">DbException(3)</A></B> that
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encapsulates an errno on failure.
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DbLog.archive
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The DbLog.archive method creates and returns an array of
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log or database file names.
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By default, DbLog.archive returns the names of all of the
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log files that are no longer in use (e.g., no longer
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involved in active transactions), and that may be archived
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for catastrophic recovery and then removed from the
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system. If there were no file names to return, list will
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be set to null.
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The flags argument is specified by <B>or</B>'ing together one or
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more of the following values:
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Db.DB_ARCH_ABS
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All pathnames are returned as absolute pathnames,
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instead of relative to the database home directory.
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Db.DB_ARCH_DATA
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Return the database files that need to be archived in
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order to recover the database from catastrophic
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failure. If any of the database files have not been
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accessed during the lifetime of the current log
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files, DbLog.archive will not include them in this
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list. It is also possible that some of the files
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referenced in the log have since been deleted from
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the system.
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Db.DB_ARCH_LOG
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Return all the log file names regardless of whether
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or not they are in use.
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The DB_ARCH_DATA and DB_ARCH_LOG flags are mutually
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exclusive.
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The DbLog.archive method throws a <B><A HREF="DbException.j.html">DbException(3)</A></B> that
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encapsulates an errno on failure.
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The DbLog.archive method is based on the C log_archive
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function, which is the underlying function used by the
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<B><A HREF="db_archive.html">db_archive(1)</A></B> utility. See the source code for the
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db_archive utility for an example of using log_archive in
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a UNIX environment. See the <B><A HREF="db_archive.html">db_archive(1)</A></B> manual page for
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more information on database archival procedures.
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DbLog.db_register
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The DbLog.db_register method registers a file name with
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the log manager and returns a file identification number.
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This file identification number should be used in all
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subsequent log messages that refer to operations on this
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file. The log manager records all file name to file
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identification number mappings at each checkpoint so that
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a recovery process can identify the file to which a record
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in the log refers.
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The DbLog.db_register method is called when an access
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method registers the open of a file. The dbp parameter
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should be a Db object which is being returned by the
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access method.
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The type parameter should be one of the Db types specified
|
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in Db.open (<B><A HREF="seeDb.html">seeDb(3)</A></B>), e.g., DB_HASH.
|
|
|
|
The DbLog.db_register method throws a <B><A HREF="DbException.j.html">DbException(3)</A></B> that
|
|
encapsulates an errno on failure.
|
|
|
|
DbLog.db_unregister
|
|
The DbLog.db_unregister method disassociates the file name
|
|
to file identification number mapping for the file
|
|
identification number specified by the fid parameter. The
|
|
file identification number may then be reused.
|
|
|
|
The DbLog.db_unregister method throws a <B><A HREF="DbException.j.html">DbException(3)</A></B>
|
|
that encapsulates an errno on failure.
|
|
|
|
DbLog.stat
|
|
The DbLog.stat function creates a statistical structure
|
|
and returns it to the caller.
|
|
|
|
The log statistics are stored in a DbLogStat object. Data
|
|
fields in DbLogStat can be accessed via get methods.
|
|
|
|
int get_st_magic();
|
|
The magic number that identifies a file as a log
|
|
file.
|
|
int get_st_version();
|
|
The version of the log file type.
|
|
int get_st_refcnt();
|
|
The number of references to the region.
|
|
int get_st_regsize();
|
|
The size of the region.
|
|
|
|
int get_st_mode();
|
|
The mode of any created log files.
|
|
int get_st_lg_max();
|
|
The maximum size of any individual file comprising
|
|
the log.
|
|
int get_st_written();
|
|
The total number of bytes written to this log.
|
|
int get_st_written_chkpt();
|
|
The number of bytes written since the last
|
|
checkpoint.
|
|
int get_st_region_wait();
|
|
The number of times that a process was able to obtain
|
|
the region lock without waiting.
|
|
int get_st_region_nowait();
|
|
The number of times that a process was forced to wait
|
|
before obtaining the region lock.
|
|
|
|
|
|
</PRE>
|
|
<H2>LOG FILE LIMITS</H2><PRE>
|
|
Log file sizes impose a time limit on the length of time a
|
|
database may be accessed under transaction protection,
|
|
before it needs to be dumped and reloaded (see <B><A HREF="db_dump.html">db_dump(3)</A></B>
|
|
and <B><A HREF="db_load.html">db_load(3)</A></B>). Unfortunately, the limits are
|
|
potentially difficult to calculate.
|
|
|
|
The log file name consists of "log." followed by 5 digits,
|
|
resulting in a maximum of 99,999 log files. Consider an
|
|
application performing 600 transactions per second, for 15
|
|
hours a day, logged into 10Mb log files, where each
|
|
transaction is logging approximately 100 bytes of data.
|
|
The calculation:
|
|
|
|
(10 * 2^20 * 99999) /
|
|
(600 * 60 * 60 * 15 * 100) = 323.63
|
|
|
|
indicates that the system will run out of log file space
|
|
in roughly 324 days. If we increase the maximum size of
|
|
the files from 10Mb to 100Mb, the same calculation
|
|
indicates that the application will run out of log file
|
|
space in roughly 9 years.
|
|
|
|
There is no way to reset the log file name space in
|
|
Berkeley DB. If your application is reaching the end of
|
|
its log file name space, you should:
|
|
|
|
1. Archive your databases as if to prepare for
|
|
catastrophic failure (see <B><A HREF="db_archive.html">db_archive(1)</A></B> for more
|
|
information).
|
|
|
|
2. Dump and re-load <B>all</B> your databases (see <B><A HREF="db_dump.html">db_dump(1)</A></B>
|
|
and <B><A HREF="db_load.html">db_load(1)</A></B> for more information).
|
|
|
|
3. Remove all of the log files from the database
|
|
environment (see <B><A HREF="db_archive.html">db_archive(1)</A></B> for more information).
|
|
|
|
4. Restart your applications.
|
|
|
|
|
|
</PRE>
|
|
<H2>ENVIRONMENT VARIABLES</H2><PRE>
|
|
The following environment variables affect the execution
|
|
of db_log:
|
|
|
|
DB_HOME
|
|
If the dbenv argument to DbLog.open was initialized
|
|
using db_appinit, the environment variable DB_HOME
|
|
may be used as the path of the database home for the
|
|
interpretation of the dir argument to DbLog.open, as
|
|
described in <B><A HREF="db_appinit.html">db_appinit(3)</A></B>. Specifically, DbLog.open
|
|
is affected by the configuration string value of
|
|
DB_LOG_DIR.
|
|
|
|
TMPDIR
|
|
If the dbenv argument to DbLog.open was null or not
|
|
initialized using db_appinit, the environment
|
|
variable TMPDIR may be used as the directory in which
|
|
to create the log, as described in the DbLog.open
|
|
section above.
|
|
|
|
|
|
</PRE>
|
|
<H2>ERRORS</H2><PRE>
|
|
The DbLog.open method may fail and throw a <B><A HREF="DbException.j.html">DbException(3)</A></B>
|
|
for any of the errors specified for the following DB and
|
|
library functions: <B><A HREF="DbLog.j.html">DbLog.close(3)</A></B>, <B><A HREF="DbLog.j.html">DbLog.unlink(3)</A></B>,
|
|
<B>atoi(3)</B>, <B>close(2)</B>, <B><A HREF="db_appinit.html">db_version(3)</A></B>, <B>fcntl(2)</B>, <B>fflush(3)</B>,
|
|
<B>lseek(2)</B>, <B>malloc(3)</B>, <B>memcpy(3)</B>, <B>memset(3)</B>, <B>mmap(2)</B>,
|
|
<B>munmap(2)</B>, <B>open(2)</B>, <B>opendir(3)</B>, <B>read(2)</B>, <B>readdir(3)</B>,
|
|
<B>realloc(3)</B>, <B>sigfillset(3)</B>, <B>sigprocmask(2)</B>, <B>stat(2)</B>,
|
|
<B>strchr(3)</B>, <B>strcpy(3)</B>, <B>strdup(3)</B>, <B>strerror(3)</B>, <B>strlen(3)</B>,
|
|
<B>strncmp(3)</B>, <B>unlink(2)</B>, and <B>write(2)</B>.
|
|
|
|
In addition, the DbLog.open method may fail and throw a
|
|
<B><A HREF="DbException.j.html">DbException(3)</A></B> encapsulating an errno for the following
|
|
conditions:
|
|
|
|
[EAGAIN]
|
|
The shared memory region was locked and (repeatedly)
|
|
unavailable.
|
|
|
|
[EINVAL]
|
|
An invalid flag value or parameter was specified.
|
|
|
|
The DB_THREAD flag was specified and spinlocks are
|
|
not implemented for this architecture.
|
|
|
|
The specified file size was too large.
|
|
|
|
The DbLog.close method may fail and throw a <B><A HREF="DbException.j.html">DbException(3)</A></B>
|
|
for any of the errors specified for the following DB and
|
|
library functions: <B>close(2)</B>, <B>fcntl(2)</B>, <B>fflush(3)</B>,
|
|
<B>munmap(2)</B>, and <B>strerror(3)</B>.
|
|
|
|
The DbLog.flush method may fail and throw a <B><A HREF="DbException.j.html">DbException(3)</A></B>
|
|
for any of the errors specified for the following DB and
|
|
library functions: <B>close(2)</B>, <B>fcntl(2)</B>, <B>fflush(3)</B>,
|
|
<B>fsync(2)</B>, <B>lseek(2)</B>, <B>malloc(3)</B>, <B>memcpy(3)</B>, <B>memset(3)</B>,
|
|
<B>open(2)</B>, <B>sigfillset(3)</B>, <B>sigprocmask(2)</B>, <B>stat(2)</B>,
|
|
<B>strcpy(3)</B>, <B>strdup(3)</B>, <B>strerror(3)</B>, <B>strlen(3)</B>, <B>unlink(2)</B>,
|
|
and <B>write(2)</B>.
|
|
|
|
In addition, the DbLog.flush method may fail and throw a
|
|
<B><A HREF="DbException.j.html">DbException(3)</A></B> encapsulating an errno for the following
|
|
conditions:
|
|
|
|
[EINVAL]
|
|
An invalid flag value or parameter was specified.
|
|
|
|
The DbLog.get method may fail and throw a <B><A HREF="DbException.j.html">DbException(3)</A></B>
|
|
for any of the errors specified for the following DB and
|
|
library functions: <B>atoi(3)</B>, <B>close(2)</B>, <B>fcntl(2)</B>, <B>fflush(3)</B>,
|
|
<B>lseek(2)</B>, <B>malloc(3)</B>, <B>memcpy(3)</B>, <B>memset(3)</B>, <B>open(2)</B>,
|
|
<B>opendir(3)</B>, <B>read(2)</B>, <B>readdir(3)</B>, <B>realloc(3)</B>,
|
|
<B>sigfillset(3)</B>, <B>sigprocmask(2)</B>, <B>stat(2)</B>, <B>strchr(3)</B>,
|
|
<B>strcpy(3)</B>, <B>strdup(3)</B>, <B>strerror(3)</B>, <B>strlen(3)</B>, <B>strncmp(3)</B>,
|
|
and <B>unlink(2)</B>.
|
|
|
|
In addition, the DbLog.get method may fail and throw a
|
|
<B><A HREF="DbException.j.html">DbException(3)</A></B> encapsulating an errno for the following
|
|
conditions:
|
|
|
|
[EINVAL]
|
|
An invalid flag value or parameter was specified.
|
|
|
|
The DB_FIRST flag was specified and no log files were
|
|
found.
|
|
|
|
The DbLog.file method may fail and throw a <B><A HREF="DbException.j.html">DbException(3)</A></B>
|
|
for any of the errors specified for the following DB and
|
|
library functions: <B>close(2)</B>, <B>fcntl(2)</B>, <B>fflush(3)</B>,
|
|
<B>malloc(3)</B>, <B>memcpy(3)</B>, <B>memset(3)</B>, <B>open(2)</B>, <B>sigfillset(3)</B>,
|
|
<B>sigprocmask(2)</B>, <B>stat(2)</B>, <B>strcpy(3)</B>, <B>strdup(3)</B>,
|
|
<B>strerror(3)</B>, <B>strlen(3)</B>, and <B>unlink(2)</B>.
|
|
|
|
In addition, the DbLog.file method may fail and throw a
|
|
<B><A HREF="DbException.j.html">DbException(3)</A></B> encapsulating an errno for the following
|
|
conditions:
|
|
|
|
[ENOMEM]
|
|
The supplied buffer was too small to hold the log
|
|
file name.
|
|
|
|
The DbLog.put method may fail and throw a <B><A HREF="DbException.j.html">DbException(3)</A></B>
|
|
for any of the errors specified for the following DB and
|
|
library functions: <B>close(2)</B>, <B>fcntl(2)</B>, <B>fflush(3)</B>,
|
|
<B>fsync(2)</B>, <B>lseek(2)</B>, <B>malloc(3)</B>, <B>memcpy(3)</B>, <B>memset(3)</B>,
|
|
<B>open(2)</B>, <B>sigfillset(3)</B>, <B>sigprocmask(2)</B>, <B>stat(2)</B>,
|
|
<B>strcpy(3)</B>, <B>strdup(3)</B>, <B>strerror(3)</B>, <B>strlen(3)</B>, <B>time(3)</B>,
|
|
<B>unlink(2)</B>, and <B>write(2)</B>.
|
|
|
|
In addition, the DbLog.put method may fail and throw a
|
|
<B><A HREF="DbException.j.html">DbException(3)</A></B> encapsulating an errno for the following
|
|
conditions:
|
|
|
|
[EINVAL]
|
|
An invalid flag value or parameter was specified.
|
|
|
|
The record to be logged is larger than the maximum
|
|
log record.
|
|
|
|
The DbLog.unlink method may fail and throw a
|
|
<B><A HREF="DbException.j.html">DbException(3)</A></B> for any of the errors specified for the
|
|
following DB and library functions: <B>close(2)</B>, <B>fcntl(2)</B>,
|
|
<B>fflush(3)</B>, <B>malloc(3)</B>, <B>memcpy(3)</B>, <B>memset(3)</B>, <B>mmap(2)</B>,
|
|
<B>munmap(2)</B>, <B>open(2)</B>, <B>sigfillset(3)</B>, <B>sigprocmask(2)</B>,
|
|
<B>stat(2)</B>, <B>strcpy(3)</B>, <B>strdup(3)</B>, <B>strerror(3)</B>, <B>strlen(3)</B>, and
|
|
<B>unlink(2)</B>.
|
|
|
|
In addition, the DbLog.unlink method may fail and throw a
|
|
<B><A HREF="DbException.j.html">DbException(3)</A></B> encapsulating an errno for the following
|
|
conditions:
|
|
|
|
[EBUSY]
|
|
The shared memory region was in use and the force
|
|
flag was not set.
|
|
|
|
The DbLog.archive method may fail and throw a
|
|
<B><A HREF="DbException.j.html">DbException(3)</A></B> for any of the errors specified for the
|
|
following DB and library functions: <B><A HREF="DbLog.j.html">DbLog.compare(3)</A></B>,
|
|
<B><A HREF="DbLog.j.html">DbLog.get(3)</A></B>, <B>close(2)</B>, <B>fcntl(2)</B>, <B>fflush(3)</B>, <B>getcwd(3)</B>,
|
|
<B>malloc(3)</B>, <B>memcpy(3)</B>, <B>memset(3)</B>, <B>open(2)</B>, <B>qsort(3)</B>,
|
|
<B>realloc(3)</B>, <B>sigfillset(3)</B>, <B>sigprocmask(2)</B>, <B>stat(2)</B>,
|
|
<B>strchr(3)</B>, <B>strcmp(3)</B>, <B>strcpy(3)</B>, <B>strdup(3)</B>, <B>strerror(3)</B>,
|
|
<B>strlen(3)</B>, and <B>unlink(2)</B>.
|
|
|
|
In addition, the DbLog.archive method may fail and throw a
|
|
<B><A HREF="DbException.j.html">DbException(3)</A></B> encapsulating an errno for the following
|
|
conditions:
|
|
|
|
[EINVAL]
|
|
An invalid flag value or parameter was specified.
|
|
|
|
The log was corrupted.
|
|
|
|
The DbLog.db_register method may fail and throw a
|
|
<B><A HREF="DbException.j.html">DbException(3)</A></B> for any of the errors specified for the
|
|
following DB and library functions: <B>close(2)</B>, <B>fcntl(2)</B>,
|
|
<B>fflush(3)</B>, <B>fsync(2)</B>, <B>lseek(2)</B>, <B>malloc(3)</B>, <B>memcmp(3)</B>,
|
|
<B>memcpy(3)</B>, <B>memset(3)</B>, <B>open(2)</B>, <B>realloc(3)</B>, <B>sigfillset(3)</B>,
|
|
<B>sigprocmask(2)</B>, <B>stat(2)</B>, <B>strcpy(3)</B>, <B>strdup(3)</B>,
|
|
<B>strerror(3)</B>, <B>strlen(3)</B>, <B>time(3)</B>, <B>unlink(2)</B>, and <B>write(2)</B>.
|
|
In addition, the DbLog.db_register method may fail and
|
|
throw a <B><A HREF="DbException.j.html">DbException(3)</A></B> encapsulating an errno for the
|
|
following conditions:
|
|
|
|
[EINVAL]
|
|
An invalid flag value or parameter was specified.
|
|
|
|
The DbLog.db_unregister method may fail and throw a
|
|
<B><A HREF="DbException.j.html">DbException(3)</A></B> for any of the errors specified for the
|
|
following DB and library functions: <B>close(2)</B>, <B>fcntl(2)</B>,
|
|
<B>fflush(3)</B>, <B>fsync(2)</B>, <B>lseek(2)</B>, <B>malloc(3)</B>, <B>memcpy(3)</B>,
|
|
<B>memset(3)</B>, <B>open(2)</B>, <B>sigfillset(3)</B>, <B>sigprocmask(2)</B>,
|
|
<B>stat(2)</B>, <B>strcpy(3)</B>, <B>strdup(3)</B>, <B>strerror(3)</B>, <B>strlen(3)</B>,
|
|
<B>time(3)</B>, <B>unlink(2)</B>, and <B>write(2)</B>.
|
|
|
|
In addition, the DbLog.db_unregister method may fail and
|
|
throw a <B><A HREF="DbException.j.html">DbException(3)</A></B> encapsulating an errno for the
|
|
following conditions:
|
|
|
|
[EINVAL]
|
|
An invalid flag value or parameter was specified.
|
|
|
|
|
|
</PRE>
|
|
<H2>BUGS</H2><PRE>
|
|
The log files are not machine architecture independent.
|
|
Specifically, their metadata are not stored in a fixed
|
|
byte order.
|
|
|
|
|
|
</PRE>
|
|
<H2>SEE ALSO</H2><PRE>
|
|
<B><A HREF="db_archive.html">db_archive(1)</A></B>, <B><A HREF="db_checkpoint.html">db_checkpoint(1)</A></B>, <B><A HREF="db_deadlock.html">db_deadlock(1)</A></B>, <B><A HREF="db_dump.html">db_dump(1)</A></B>,
|
|
<B><A HREF="db_load.html">db_load(1)</A></B>, <B><A HREF="db_recover.html">db_recover(1)</A></B>, <B><A HREF="db_stat.html">db_stat(1)</A></B>, <B><A HREF="db_intro.html">db_intro(3)</A></B>,
|
|
<B><A HREF="db_internal.html">db_internal(3)</A></B>, <B><A HREF="db_thread.html">db_thread(3)</A></B>, <B><A HREF="Db.j.html">Db(3)</A></B>, <B><A HREF="Dbc.j.html">Dbc(3)</A></B>, <B><A HREF="DbEnv.j.html">DbEnv(3)</A></B>,
|
|
<B><A HREF="DbException.j.html">DbException(3)</A></B>, <B><A HREF="DbInfo.j.html">DbInfo(3)</A></B>, <B><A HREF="DbLock.j.html">DbLock(3)</A></B>, <B><A HREF="DbLockTab.j.html">DbLockTab(3)</A></B>, <B><A HREF="DbLog.j.html">DbLog(3)</A></B>,
|
|
<B><A HREF="DbLsn.j.html">DbLsn(3)</A></B>, <B><A HREF="DbMpool.j.html">DbMpool(3)</A></B>, <B><A HREF="Dbt.j.html">Dbt(3)</A></B>, <B><A HREF="DbTxn.j.html">DbTxn(3)</A></B>, <B><A HREF="DbTxnMgr.j.html">DbTxnMgr(3)</A></B>
|
|
|
|
</PRE>
|
|
<HR SIZE=1 NOSHADE>
|
|
<ADDRESS>
|
|
Man(1) output converted with
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<a href="http://www.oac.uci.edu/indiv/ehood/man2html.html">man2html</a>
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</ADDRESS>
|
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