10.05.2014 9:03, Molnár Attila wrote: > *VARIANT data type in PSQL* > - gain : a little memory and/or CPU overhead but much cleaner code. Also > rdb$get/set_context value colud be variant.
Welcome to the hell of unpredictable type conversion. > *Optimization II. > * - temporal indexing of materialization : e.g. when ORDER/GROUP BY has no > index then > currently the whole resultset is materialized, and the sorting moves the > whole row each > time. Instead of this it should create a temporal index on the order/group > columns then > fetching on the temporal index. In this way much less writes needed. This > shold be applied > after a treshold : common sense sais after index size/row size rate is > smaller than 0.5. Uncommon sense says that random IO can be much more than two times slower. -- WBR, SD. ------------------------------------------------------------------------------ Is your legacy SCM system holding you back? Join Perforce May 7 to find out: • 3 signs your SCM is hindering your productivity • Requirements for releasing software faster • Expert tips and advice for migrating your SCM now http://p.sf.net/sfu/perforce Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
