On 25-2-2017 11:15, Dmitry Yemanov wrote: > 25.02.2017 12:37, Mark Rotteveel wrote: > >>> Do you/anyone know if these engines return full results sets or follow the >>> "page set" approach? >> >> As far as I know Oracle[1], PostgreSQL[2], SQL Server[3] support it. I >> believe MySQL does as well. Don't know about other database systems, but >> I assume most of them will support this (the SQL CLI standard also >> defines it). > > AFAIK, in these databases page sets are primarily a transport/API > feature. The important question, however, is whether the engine does > some work during fetch() besides copying the row(s) for the next batch. > I suspect InterBase/Firebird is the only engine that may process > execute() as a no-op and perform all the data retrieval / joining / etc > during fetching.
I know Oracle does, although it might depend on some optimizer decisions and hints (eg first_rows(n) hint). Not sure about the others. Mark -- Mark Rotteveel ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, SlashDot.org! http://sdm.link/slashdot Firebird-Devel mailing list, web interface at https://lists.sourceforge.net/lists/listinfo/firebird-devel
