JG wrote: > To specify further, the question is, can I count on PostgreSQL to denormalize the database when it > would be better for the performance, or should I always denormalize the database and all the querys > myself. PostgreSQL does not do such things automatically. You'll have to do so yourself. > I have looked for answers on the subject, but all I managed to find was a wiki article at > http://en.wikipedia.org/wiki/Denormalization that says: > > "The preferred method is to keep the logical design normalised, but allow the database management > system (DBMS) to store additional redundant information on disk to optimise query response. In this > case it is the DBMS software's responsibility to ensure that any redundant copies are kept consistent. > This method is often implemented in SQL as indexed views (Microsoft SQL Server) or materialised views > (Oracle)." > > So in the case of PostgreSQL, do I also have to use views or are there some other ways? Views won't help you. A materialized view is actually a table that holds a (possibly aggregated) copy of data from elsewhere in the database. Apart from materialized views, you can denormalize for performance by adding columns to tables that store a copy of information from another table, with the benefit that you can avoid joins to access the information. The problem you have to solve when you use denormalization techniques is to keep the data and the copy consistent. Yours, Laurenz Albe -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
