Db::set_h_nelem

#include <db_cxx.h> int Db::set_h_nelem(u_int32_t h_nelem); 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 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. Errors The Db::set_h_nelem method may fail and throw an exception or return 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 or return a non-zero error 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 either return DB_RUNRECOVERY or throw an exception encapsulating DB_RUNRECOVERY, 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::err, Db::errx 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_alloc, Db::set_append_recno, Db::set_bt_compare, Db::set_bt_minkey, Db::set_bt_prefix, Db::set_cachesize, Db::set_dup_compare, Db::set_errcall, Db::set_errfile, Db::set_errpfx, Db::set_feedback, Db::set_flags, Db::set_h_ffactor, Db::set_h_hash, Db::set_h_nelem, Db::set_lorder, Db::set_pagesize, Db::set_paniccall, 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.