# Db.set_h_nelem

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    import com.sleepycat.db.*;

    public void set_h_nelem(int h_nelem)
        throws DbException;

# Description

Set an estimate of the final size of the hash table.

If not set or set too low, hash tables will still expand gracefully as keys are entered, although a slight performance degradation may be noticed.

The Db.set_h_nelem interface may be used only to configure Berkeley DB before the Db.open interface is called.

The Db.set_h_nelem method throws an exception that encapsulates a non-zero error value on failure.

# Errors

The Db.set_h_nelem method may fail and throw an exception encapsulating a non-zero error for the following conditions:

EINVAL
  An invalid flag value or parameter was specified.

  Called after Db.open was called.

The Db.set_h_nelem method may fail and throw an exception for errors specified for other Berkeley DB and C library or system methods. If a catastrophic error has occurred, the Db.set_h_nelem method may fail and throw a DbRunRecoveryException, in which case all subsequent Berkeley DB calls will fail in the same way.

# Class

Db

# See Also

Db.associate, Db.close, Db.cursor, Db.del, Db.fd, Db.get, Db.pget, Db.get_byteswapped, Db.get_type, Db.join, Db.key_range, Db.open, Db.put, Db.remove, Db.rename, Db.set_append_recno, Db.set_bt_minkey, Db.set_cachesize, Db.set_errcall, Db.set_errpfx, Db.set_feedback, Db.set_flags, Db.set_h_ffactor, Db.set_h_nelem, Db.set_lorder, Db.set_pagesize, Db.set_q_extentsize, Db.set_re_delim, Db.set_re_len, Db.set_re_pad, Db.set_re_source, Db.stat, Db.sync, Db.truncate, Db.upgrade, and Db.verify.`

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