The DBMS_STATS Package

Following a brief introduction to the procedures of the DBMS_STATS package in section 1, section 2 looks at the differences of GATHER_XXX_STATS between Oracle 8 and 9. It will further show ways of transferring statistics between databases with caveats on what to watch for when using production statistics in a test database. Finally, in section 3 we will show two scenarios where the deliberate use of SET_COLUMN_STATS to change column statistics helps the optimizer choose a better, faster and more scalable access plan. The goal is to promote the notion that the statistics are a means to give the CBO information about the data in the database in order to enable it to make the best possible access path decisions and that the statistics are not a “sacred cow ” but that it is OK to alter them in order to give the optimizer better information. The findings presented are based on experience and tests with Oracle 8i (8.1.7) on Windows 2000, Linux Redhat 7.2, HP-UX 11.0, and Compaq Tru64 5.1. Comments on changes in Oracle 9i are based on Oracle 9.2.0 on Windows 2000 an

The problem of success: What is a ‘good’ homicide investigation?

Police detectives traditionally defined a successful homicide investigation as involving a suspect being identified, charged and ultimately convicted – preferably for murder. However, it is increasingly being recognised, not least by police officers themselves, that definitions of success can be more complex. Informed by empirical data drawn from field studies of police murder investigations in the UK, this article identifies four alternate definitions of investigative success: (i) outcome success, (ii) procedural success, (iii) community impact reduction success and (iv) preventative success. These ways of socially constructing the ‘success’ or otherwise of homicide investigation work are framed by the different perspectives and pressures that attend to different roles within the police organisation. The article concludes by considering the wider implications of these issues for thinking about police performance and contemporary understandings of ‘good’ policing