Re: Blob Performance

Hi Art, One last thing. I modified the blobload program that comes with esql/c to use the LOCUSER functions like you said. My loc_read function always seems to get called with 1024(bytes to transfer), i can't seem to get this number larger. I tried setting loc_bufsize but it seems to be ignored. I set loc_size = -1 and also set fetchbufsize to 32767. Anything else i can do? Thanks, Bill "Art S. Kagel" <kagel@bloomberg.net> wrote in message news:pan.2003.10.28.18.45.17.210129.10594@bloomberg.net... > On Tue, 28 Oct 2003 17:50:07 -0500, Bill Hunt wrote: > > Sorry, I try my best to avoid having anything more to do with WinXX than I have > to. > > Art S. Kagel > > > Thanks Art, > > Is there anyway to change the packet size for a VB app using oledb? > > Also there is a variable in setnet call FET_BUFF_SIZE that i set to 32767. > > After setting this value i seem to get much faster transfer rates sometimes. > > It actually seems that every other time I log in the speed goes from fast to > > extremely slow. Our customer periodially saves large blobs to the DB(20-30 > > meg) and they are complaing about performace(several minutes to save a file). > > The app is in VB.NET using the oledb provider from informix. The only thing i > > can think to do is to create the save code in a DLL written in esqlc and use > > the technique you describe to save the BLOB. Would this even be possible? > > > > Thanks again, > > Bill > > "Art S. Kagel" <kagel@bloomberg.net> wrote in message > > news:pan.2003.10.28.16.03.04.132216.10594@bloomberg.net... > >> On Tue, 28 Oct 2003 12:05:00 -0500, Bill Hunt wrote: > >> > >> There are several things you can do to improve things: > >> > >> 1- Increase the size of the SQL Communications Buffer. This defaults to > > 4k. > >> export FETBUFSIZE=32767 (the max value) in the environment of the task > > or set > >> the global variable FetBufSize = 32767; in the program after opening > > the > >> database and before transferring any data. > >> 2- By default BLOBS are copied to the server by a client in 1K packets > > (which > >> explains the 3000 packets for the 3MB BLBO!). You can change this in > > the > >> loc_t structure before inserting the BLOB by setting loc_size to -1 and > > using > >> the LOCUSER method (you can find sample loc_open, loc_read, and > > loc_close > >> functions in my ul.ec utility in the package utils2_ak in the IIUG > > Software > >> Repository, these are VERY simple functions). > >> > >> Art S. Kagel > >> > >> > Hello, > >> > I am trying to track down a problem with inserting blobs. When i > > save a > >> > blob to a table that is around 3 meg it consistently takes 30 seconds or > > so. I > >> > am using the blobload esqlc program that comes with the client > > SDK(2.81). I > >> > have the same problem using a VB app with the informix oledb driver. > > The > >> > client is running windows XP. At first i thought it was a network issue > > on > >> > the LAN, but i can ftp the file to the server in only a second or two. > > Then I > >> > though it was something to do with how the DB was storing the blobs, but > > I was > >> > able to unload and then load a blob(the same 3 meg file) from dbaccess> > on the > >> > server in about 4 seconds. My server is Intel solaris running IDS > > 7.23UC1. > >> > One weird thing i noticed is that when i FTP'd the file to the server i > > saw > >> > 159 packets go out across the network, when i ran blobload there were > > over > >> > 3000 packets sent. Any idea what this could be or how I could > > troubleshoot > >> > the problem. > >> > > >> > Let me know if you need any more info. > >> > > >> > Bill