Scott The idea behind a dynamic file is to spread the pain of administration over the lifetime of an application. So yes, there are overheads and whilst a well-sized static file will outperform it, a dynamic file in turn will normally outperform a badly sized static file.
There are some caveats, mostly relating to accessing the file outside of the database. If you use an OS level backup or snapshot, or anything that looks at these from the OS level, you need to make sure your dynamic files are closed OR you have paused your database - Universe holds runtime dynamic file parameters in shared memory and without those getting written back to the file header (which happens in the pause) the files will break if you restore them. Most of the prejudice against them goes back to the old PICKies who migrated to Universe at a time when they weren't particularly stable and had performance issues around concurrency with the way they effectively single threaded their sizing operations. They were also doubly expensive on UNIXes that had tight limitations on the number of open (OS level) files. But that was a long time ago. Brian -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Scott Zachary Sent: 09 July 2013 17:15 To: [email protected] Subject: [U2] File type 30 (dynamic) I have very little experience with using dynamic (type 30) files and I'm looking for some pointers in that regard. I have a file that I am considering creating as a dynamic file. The file will be a log file with sequential numeric keys. The record size will normally range from about 200 to 700 bytes, with a probable maximum size of less than 1,000 bytes. We expect the file to continually grow without deletions and we will likely purge it annually. What are the pro's and con's of creating this file as type 30 verses other file types? Thanks, Scott Zachary UniVerse Developer Gardens Alive! Inc -- View this message in context: http://u2-universe-unidata.1073795.n5.nabble.com/File-type-30-dynamic-tp4112 9.html Sent from the U2 - Users mailing list archive at Nabble.com. _______________________________________________ U2-Users mailing list [email protected] http://listserver.u2ug.org/mailman/listinfo/u2-users _______________________________________________ U2-Users mailing list [email protected] http://listserver.u2ug.org/mailman/listinfo/u2-users
