000			01641nab a22002657 4500
001			H004.652.4 DIS
003			AR-sfUTN
008			190909b xx |||p|r|||| 00| 0 spa d
040			_cAR-sfUTN
080			_aH004.652.4 DIS
100			_aYu, Min J.
700			_aSheu, Phillip C.-Y.
245			_aAdaptive join algorithms in dynamic distributed databases
336			_2rdacontent _atexto _btxt
337			_2rdamedia _asin mediación _bn
338			_2rdacarrier _avolumen _bnc
505			_aThis paper addresses the problem of query optimization fordynamic databases in distributed environments where data frequently changetheir values. An adaptive query optimization algorithm is proposed toevaluate queries. Rather than constructing a full plan for an access path andexecuting it, the algorithm constructs a partial plan, executes it, updatesthe statistics, and constructs a new partial plan. Since a partial plan isconstructed based on the latest statistics, the algorithm is adaptive to data modifications and errors from the statistics. The algorithm extends the SDD-1algorithm by considering local processing cost as well as communication cost.Whereas the SDD-1 algorithm only uses semi-joins to reduce communication cost,the algorithm reduces it with joins as well. It is proved that the adaptivealgorithm is more efficient than the SDD-1 algorithm.
650			_aDATABASE
650			_aQUERY OPTIMIZATION
650			_aJOIN
650			_aADAPTIVE
773			_tDistributed and parallel databases _wH004.652.4 DIS _nS.T.:H004.652.4 DIS PP2670 _g(vol. 5, nro. 1, Jan. 1997), p. 5-30
942			_cAN
999			_c35460 _d35460