Re: NewEra is heavy!

In article <46ph8s$fmm@raffles.technet.sg>, Daniel Qiao Jianxin <daniel@santeh.com.sg> wrote: >Yes . NewEra is heavy for 486! >I have tested a completed NewEra appplication, It's >slow with my computer 486DX66/16MB RAM. After I transfer >to Pentium 90Mhz/16MB RAM , It's speed met my expectation >and performance is better. As part of my never-ending NewEra/Delphi comparison I decided to see how memory usage compared when connected to large tables (people had suggested that Delphi would not scale well). The NewEra program was built with a SuperTable and the standard Query/Retrieve/ Next/Previous buttons. Delphi's was via a TQuery object connected to a TDBNavigator object capable of understanding Query-by-examples. Delphi Memory required to NewEra One Row All Rows ---------------------------------------------------------------- Load program 2.4 meg 813k Query 3873 rows 2.4 meg 25k 361k Query 13621 rows 8.4 meg 25k 1.2 meg Query 250000(ish) rows Crashes: Out of memory 25k 4.7 meg Query 0 rows, after the 13621 query 2.9 meg 0k -------------------------------------------------------------- The astonishing thing here is that NewEra loads the ENTIRE result-set into memory, where-as Delphi loads the rows only as they're requested (which is why there are two figures in the Delphi column, the first figure is how much memory is used to display the first few rows and the second figure shows how much is used when all rows have been displayed). The out-of-memory crash is on a machine with 24meg of real memory and about 10 meg of Windows swap-space. Interestingly changes to the data made with NewEra were not mirrored on screen when the changed row is 'Previoused' back to - implying there is a big SELECT * style SCROLL CURSOR lurking in there somewhere. I am unclear how Delphi handles the scrolling of the cursor, there may be some rowids floating in the background I wonder - might not be so good on fragmented Informix 7 tables? Just keeping you all up-to-date... Regards, Kerry S ------------------------------------,------------------------------------------ Kerry Sainsbury, kerry@kcbbs.gen.nz | THE INFORMIX FAQ v2.4 Oct 95 Quanta Systems, Auckland | kcbbs.gen.nz:/informix/informix.[faq|apx] New Zealand. Work: +64 9 377-4473 | mathcs.emory.edu:/pub/informix/faq/ " " Home: +64 9 279-3571 | http://www.garpac.com/informix.html