Hi all, I am working on optimisation of the SQL queries that originally were writtent for the PostgreSQL. I am interested in knowledge of the algorithms that SAP DB uses to perform JOINS/aggregations.
Does SAP DB implements the merge join/hash joins algorithms as PostgreSQL and some other DBMS does? If we have simple join on condition table1.key = table2.key with the indexes defined for both columns what is the estimation for the "cost" of this operation? It should significantly depend of the join algorithm. If the nested loop algorithm is used the estimation is around n1*log2(n2) rows while in case of the merge join it's ~ n1+n2 rows. I have not found any information on this mailing list about this matter. I appreciate any information related to this matter. Thanks in advance. Dmitri Lyssenko, Nuix Pty. Ltd. _______________________________________________ sapdb.general mailing list [EMAIL PROTECTED] http://listserv.sap.com/mailman/listinfo/sapdb.general
