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<title>Berkeley DB: DbEnv::set_lg_max</title>
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<h1>DbEnv::set_lg_max</h1>
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#include <db_cxx.h>
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DbEnv::set_lg_max(u_int32_t lg_max);
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<p>Set the maximum size of a single file in the log, in bytes. By default,
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or if the <b>lg_max</b> argument is set to 0, a size of 10MB is used.
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Because <a href="../api_cxx/lsn_class.html">DbLsn</a> file offsets are unsigned four-byte values, the
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set value may not be larger than the maximum unsigned four-byte value.
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The size of the log file must be at least four times the size of the
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in-memory log buffer (see <a href="../api_cxx/env_set_lg_bsize.html">DbEnv::set_lg_bsize</a>).
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<p>See <a href="../ref/log/limits.html">Log File Limits</a>
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<p>The DbEnv::set_lg_max method configures a database environment, not only operations
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performed using the specified <a href="../api_cxx/env_class.html">DbEnv</a> handle.
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<p>The DbEnv::set_lg_max interface may be called at any time during the life of
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If no size is specified by the application, the size last specified for
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the database region will be used, or if no database region previously
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existed, the default will be used.
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<p>The DbEnv::set_lg_max method either returns a non-zero error value or throws an exception that
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encapsulates a non-zero error value on failure, and returns 0 on success.
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<p>The database environment's log file size may also be set using the environment's
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<b>DB_CONFIG</b> file. The syntax of the entry in that file is a
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single line with the string "set_lg_max", one or more whitespace characters,
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and the size in bytes. Because the <b>DB_CONFIG</b> file is read when the database
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environment is opened, it will silently overrule configuration done
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<p>The DbEnv::set_lg_max method may fail and throw an exception or return a non-zero error for the following conditions:
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<p><dt>EINVAL<dd>An invalid flag value or parameter was specified.
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<p>Called after <a href="../api_cxx/env_open.html">DbEnv::open</a> was called.
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<p>The size of the log file is less than four times the size of the in-memory
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<p>The specified log file size was too large.
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<p>The DbEnv::set_lg_max method may fail and throw an exception or return a non-zero error for errors specified for other Berkeley DB and C library or system methods.
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If a catastrophic error has occurred, the DbEnv::set_lg_max method may fail and
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either return <a href="../ref/program/errorret.html#DB_RUNRECOVERY">DB_RUNRECOVERY</a> or throw a
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<a href="../api_cxx/runrec_class.html">DbRunRecoveryException</a>,
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in which case all subsequent Berkeley DB calls will fail in the same way.
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<a href="../api_cxx/env_class.html">DbEnv</a>, <a href="../api_cxx/logc_class.html">DbLogc</a>, <a href="../api_cxx/lsn_class.html">DbLsn</a>
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<a href="../api_cxx/log_list.html">Logging Subsystem and Related Methods</a>
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