Hi All, After a while on RDB DAS beta1 , I am trying to do more on XQuery DAS.
Tried to check different XQuery implementations available, below is summary: http://www.axyana.com///products.html Quizx/open - open source Quizx/db(XQuest) - not open source http://www.gnu.org/software/qexo/ - license? - kawa it compiles XQuery expressions and programs to Java bytecodes , this does not have API to be used, so not of much use http://www.oracle.com/technology/sample_code/tech/xml/xmldb/jxqi.html - license will be a problem ***http://dsd.lbl.gov/nux/api/index.html - http://dsd.lbl.gov/nux/license.html has good set of APIs. I am not sure if the license poses some restrictions on use. Looks like this will be a good choice to give first attempt for XQuery DAS. Any advise? http://saxon.sourceforge.net/ - only SAXON-B is fee and SAXON-SA is commercial,So may not be a good choice I am trying to start based on https://svn.apache.org/repos/asf/incubator/tuscany/sandbox/lresende/das/ This uses Service Provider API to separate different DAS implementations. There is http://www.mail-archive.com/[email protected]/msg14428.htmlthread to discuss the high level approach to provide this. Please add your comments there for refactoring approach. We can use the current mail thread for XQuery DAS specific comments. Also, I will use a new page on http://cwiki.apache.org/confluence/display/TUSCANYWIKI/Home to track detailed status for XQuery DAS. I will make sure not to link this page to any other page, so as not to mess up with ongoing release. Regards, Amita On 4/4/07, Luciano Resende <[EMAIL PROTECTED]> wrote:
Hi Amita Related to the features, I think it's fine to start simple and get improvements gradatively as we progress... Some issues that you have identified: - Config model more flexible to accommodate differences between multiple implementation - Factory issues, and the ability to get different implementations Are already available in my sandbox [1] as part of the work I did to accommodate multiple DAS implementations [2] It's probably good idea to keep a XQuery DAS page on the Wiki and keep updating it with requirements, discussions and design we are taking... [1] - https://svn.apache.org/repos/asf/incubator/tuscany/sandbox/lresende/das/ [2] - http://www.mail-archive.com/[email protected]/msg14428.html On 3/26/07, Amita Vadhavkar <[EMAIL PROTECTED]> wrote: > > Hi All, > I am trying to create a prototype for supporting XQuery-DAS. Below are > some points I have gathered so far. > Please give your comments, add to the points. > > 1) Basic Features that can be supported:- > >>Need to support associating path expression to xml data source. > > >>Parameter passing in path expression > > >>Support for FLWOR expressions - use of parameters, data source name > > >>JOIN operation will involve multiple data sources and multiple > expressions > - need to support association > for same. > > >>Support for XQuery update facility > > 2) Places where current das config/code needs to be modified:- > >>Provide flexibility in config to support RDB/XQUery/xyz...Can have > expansion to > current config.xsd to support multiple connections of multiple types? like > RDB/XQuery... > > >>Command - needs to take care of associating multiple data sources with > multiple expressions > say, in RDB - its select from t1, t2... > in XQuery - the FLWOR - we can say books.xml <-> expr1, stores.xml <-> > expr2 > and have a JOIN. > > >>Getting connection to data store - should be in Interface-Impl , not > directly in impl- like > it is currently there in DASImpl not in DAS, to keep it generic. > > >>graph building related classes should also have separation of interface > and implementation. > > > 3) What can be kept for in-future and what is MUST for the first cut:- > Need comments from you all. > > 4) Questions:- > >>In RDB-DAS we do not support connection to multiple databases. Even > JIRA-952 talks > only about multiple schemas. Is there any requirement for this/ constraint > due to which > we need to stick to single database? > > >>Also, in future, there can be mix of data stores, RDB, XQuery, .... What > are the pros/cons > for supporting connection to multiple different types of datastores > (like one RDB compliant, one XQuery compliant) > > 5) Link from ML - [DAS] Refactoring DAS to allow multiple implementatons > http://www.mail-archive.com/[email protected]/msg14428.html > During the attempt to separate APIs from Impl, we can now decide on the > approach and structure the design. > > Regards, > Amita > -- Luciano Resende http://people.apache.org/~lresende
