Re: [PATCHES] SQL conformance related patch
От | Simon Riggs |
---|---|
Тема | Re: [PATCHES] SQL conformance related patch |
Дата | |
Msg-id | 1101677725.2963.63.camel@localhost.localdomain обсуждение исходный текст |
Ответ на | Re: [PATCHES] SQL conformance related patch (Peter Eisentraut <peter_e@gmx.net>) |
Список | pgsql-docs |
On Fri, 2004-11-26 at 22:34, Peter Eisentraut wrote: > Simon Riggs wrote: > > The sections Supported Features and Unsupported Features cover both > > Mandatory (Core) and Optional features in the same section. It would > > be better to separate these, just as the SQL standard itself does in > > Annex F - SQL Feature Taxonomy. > > Please note that all that has been suggested is splitting a table into two pieces, so that it matches the SQL:2003 standard's way of presenting this information, as laid out in Annex F - SQL Feature Taxonomy. I found that arrangement useful in understanding the standard and wished to recommend it to the project. > > This seems especially important for the Unsupported Features section, > > since the length of the list makes it look like 100% support is a > > long way off, whereas it is only 14 features away, and many of them > > minor [see Troels' low hanging fruit list on this thread] > > If the "core" set of features were at all useful in practice then I > would think about this, but it is not, so we'd just end up arranging > the tables for marketing purposes instead of information purposes. Ten > years ago this would have been equivalent to making a separate section > for SQL 92 Entry level and rejoicing upon completion, while realizing > that a real-life DBMS needs at least Intermediate level. I agree completely with your assessment of SQL-92 Entry and Intermediate level. Having recently spent an hour or two looking at the SQL:2003 standard, I don't think the analogy that SQL:2003 Core is similar to SQL-92 Entry level is a useful one. I understand why people would think this, because I would definitely have thought exactly the same, before I looked. For example, Microsoft SQL Server claims SQL-92 Entry level. If SQL:2003 were similar then they would simply switch the claim to SQL:2003 without problem. They do not, because they cannot. Please review what the list of SQL:2003 Core features contains: SAVEPOINTS, outer joins, triggers, derived tables, quantified sub-selects, constraints etc.. but not object-relational features, which are only Optional. IMHO these features are useful in practice. Yes, there are also many Optional features that are also desirable. -- Best Regards, Simon Riggs
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