Path: dp-news.maxwell.syr.edu!spool.maxwell.syr.edu!drn.maxwell.syr.edu!news.maxwell.syr.edu!transit.news.xs4all.nl!newsgate.news.xs4all.nl!transit3.news.xs4all.nl!post.news.xs4all.nl!not-for-mail Date: Thu, 05 May 2005 15:45:40 +0200 From: mAsterdam User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7) Gecko/20040616 X-Accept-Language: en-us, en MIME-Version: 1.0 Newsgroups: comp.databases.theory Subject: Re: Development as Configuration References: <1114878474.300038.283430@o13g2000cwo.googlegroups.com> <1115142321.507691.302070@o13g2000cwo.googlegroups.com> <1115150900.677582.195380@g14g2000cwa.googlegroups.com> <42780f9f$0$153$e4fe514c@news.xs4all.nl> <1115220865.664811.33030@z14g2000cwz.googlegroups.com> In-Reply-To: <1115220865.664811.33030@z14g2000cwz.googlegroups.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Lines: 47 Message-ID: <427a2386$0$15638$e4fe514c@news.xs4all.nl> NNTP-Posting-Host: 82.92.225.151 X-Trace: 1115300743 news.xs4all.nl 15638 [::ffff:82.92.225.151]:16796 X-Complaints-To: abuse@xs4all.nl Xref: dp-news.maxwell.syr.edu comp.databases.theory:30707 dawn wrote: >mAsterdam wrote: >>dawn wrote: >>>... and then often SQL for persistence, ... >> >>Why use SQL for persistence? Any filesystem could provide that, no? > > An obvious mAstersam response ;-) so here is mine: > > There are two reasons for using SQL as the API for persistance. > 1) If someone else determined at some other time that a SQL-DBMS would > be used for storing the data with which my app is working or Portability of the interface to your data - not persistence. > 2) If I determined that there were features of a SQL-DBMS that gave an > advantage over a simple file system so that I chose to use PostgreSQL, > for example, for a given project. Because SQL is so pervasive in tools > that have as a PRIMARY feature (smiling) an API for creating, reading, > updating, and deleting data on secondary storage devices, it is often > used in even the simplest database applications. Glad to see you smile :-) But why bother to go the extra kilometer if a filesystem provides perfect persistence? I think it is good to use an interface for the right reasons. I suggest persistence is not the right reason to use a database or SQL. To identify what the true reasons are, just imagine you would have a filesystem for persistence. Which problems will you have? To address those maybe SQL comes back in. But now you have the right reasons, and more realistic expectations. > Sure, there are other features that are important for DBMS tools, such > as security and referential integrity, but many a software application > has included code for those features too. To date it appears to me > that people license DBMS tools for the PRIMARY, not negotiable, feature > of having an API for creating, reading, updating, and deleting data on > secondary storage devices, even if there are other important features > too. Right? IMHO DBMS tools can deliver their benefits by encapsulating, hiding storage considerations from the application. Delivering storage to the application is the means, not the end. You don't want a room, you already have it. The DBMS is the locks on the doors and the organization of the room - not the room itself.