SCO-ISAM problem

Path: emory!gatech!bloom-beacon!eru!hagbard!sunic!news.funet.fi!fuug!tuura!esmi From: esmi@tuura.UUCP (Esmi kulunvalvonta) Newsgroups: comp.databases Keywords: isam Message-ID: <1417@tuura.UUCP> Date: 18 Sep 91 11:39:40 GMT Organization: Nokia Data Systems Oy We have been previously successfully using Informix C-ISAM in our 286-based software. Now when we are moving to 386-based software we decided to change our isam to SCO-ISAM as this comes free with the SCO's ODT development system which is our development base ( ODT dev sys 1.0.1d ) We have come against some problems when porting our software to SCO-ISAM. These are caused by the SCO-ISAM file locking system using semaphores, shared memory and an environment variable DBKEY. Our software consists mainly of a screen process updating the isam database and a data-collecting process using the isam database. Both processes works fine alone, but when one process is active and the other is started it aborts. The problem is inside the isopen function call. The data-collecting process keeps 6 files constantly open. When the screen process starts and tries to open an isam file it aborts (memory fault - segmentation violation). With sdb the problem is located to the alloc_fle- function in the isopen-call. If the screen process is active and the data-collecting process is started it aborts in a more behaved manner ie when trying to open the second isam-file it returns the isam error 115. (cannot create lock file). We are not actually using file locking at all, all files are opened with ISMANULOCK. There are no similar problems if we have several active screen procesess alternavely several active collecting processes. Neither are there any problems if the processes have different DBKEY:s, although then the data collecting process cannot read data updated by the screen process. The problem which seems to be specific to the SCO-ISAM file locking scheme is quite critical and may stop our use of SCO-ISAM if we cannot find a solution to it. Bengt Bredenberg Phone : 358 0 452 7217 Software manager Fax : 358 0 452 7102 Esmi security Mail : esmi@yj.data.nokia.fi PB 95, 02201 Espoo FINLAND