The increase in file size you see at the OS level is due to overflow. With static files, what is "static" is the modulo -- it doesn't change unless you resize the file. The modulo determines the number of "groups" in the file; each group is allocated a primary buffer of a set size -- in your case, 16K. When more data is written to a particular group than can be held in the primary buffer of 16K the data is stored in overflow. Overflow buffers are NOT allocated to the file at creation and must be added dynamically as needed. At the OS level, overflow buffers are appended to the file, extending its length. This produces the increase in size that you are seeing.
The FILE.STAT shows 62 groups in level one overflow. The file has largish records (9255 bytes on average) and a largish standard deviation (28,809) so I'd expect a lot of overflow distributed unevenly. Probably some of the overflow in the 62 overflown groups is in fairly long chains. Probably some very large records were added to the file during the two hour period. HTH, Jeff Fitzgerald Fitzgerald & Long, Inc. www.fitzlong.com -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jeff Butera Sent: Sunday, April 13, 2008 12:51 PM To: [email protected] Subject: [U2] Unidata file size I'm running Unidata 7.1.8 on Solaris 9. I have a static hashed file with modulo 5009 and block size of 16K. I didn't think static hashed files would change size at the OS level, but this one is. Am I just wet behind the ears or do I just misunderstand static hashing? Here's the file this afternoon: -rwxrwx--- 1 datatel staff 102105088 Apr 13 12:32 WWW.STATE and about two hours later: -rwxrwx--- 1 datatel staff 121372672 Apr 13 14:44 WWW.STATE Since I know someone might ask: File name = WWW.STATE Number of groups in file (modulo) = 5009 Static hashing, hash type = 0 Block size = 16384 File has 62 groups in level one overflow. Number of records = 505 Total number of bytes = 4673742 Average number of records per group = 0.1 Standard deviation from average = 0.3 Average number of bytes per group = 933.1 Standard deviation from average = 9586.7 Average number of bytes in a record = 9254.9 Average number of bytes in record ID = 21.6 Standard deviation from average = 28809.0 Minimum number of bytes in a record = 51 Maximum number of bytes in a record = 381892 Minimum number of fields in a record = 1 Maximum number of fields in a record = 827 Average number of fields per record = 80.9 Standard deviation from average = 134.7 Jeff Butera, Ph.D. Administrative Systems Hampshire College [EMAIL PROTECTED] 413-559-5556 "Working with them is like going to Las Vegas: sometimes you get lucky and sometimes you don't." Dan Parker ------- u2-users mailing list [email protected] To unsubscribe please visit http://listserver.u2ug.org/ ------- u2-users mailing list [email protected] To unsubscribe please visit http://listserver.u2ug.org/
