- From: Richard Cyganiak <richard@cyganiak.de>
- Date: Mon, 13 Feb 2012 23:28:22 +0000
- To: Eric Prud'hommeaux <eric@w3.org>
- Cc: Juan Sequeda <juanfederico@gmail.com>, public-rdb2rdf-wg@w3.org
On 13 Feb 2012, at 18:19, Eric Prud'hommeaux wrote: >> But from what I hear, you can query the remote >> table by >> >> select * from remoteserver.remotedb.remoteschema.remotetable > > I read that as #2 then. Isn't > remoteserver.remotedb.remoteschema.remotetable illegal in conventional > SQL? A fully qualified name in standard SQL is something like catalog.schema.table.column. My understanding is that federation systems make remote DBs show up as additional catalogs beside the default one. Best, Richard > > >> SQL Server has a defined mapping of their types with other types. If I >> understand correctly, you either bring in the table into you local sql >> server, or you can also push parts of the query to the remote database, and >> they can translate sql server sql to other sql dialects. >> >> >> >>> >>> 2. User queries are expressed in an SQL-like language with extra >>> productions to target joins against particular databases. >>> >>> >> Not that I'm aware of. >> >> >>> 3. Configuration created a virtual warehouse in a single schema. User >>> queries against this warehouse/view are re-written to connect to the remote >>> database. >>> >> >> This is just the general ETL data warehouse data integration approach, >> right :) > > pretty much, though I have the impression that most of these > wharehouses are materialized, potentially not using any expressivity > beyond SQL (i.e. you write some java code to do SQL SELECTs from your > various authoritative databases and INSERTs into the warehouse). > > >>>> I'm giving the Linked Data tutorial at semtech. If our tutorials don't >>>> overlap, I could help you out with this. >>> >>> Excellent -- tx. >>> >>> >> Don't quote me on any of this ;) I could get confirmation and we could work >> this out together. >> >> >>> >>>> Juan Sequeda >>>> +1-575-SEQ-UEDA >>>> www.juansequeda.com >>>> >>>> >>>> On Mon, Feb 13, 2012 at 10:13 AM, Eric Prud'hommeaux <eric@w3.org> >>> wrote: >>>> >>>>> I'm giving a talk at SemTech which I'm lead to believe will cover >>> SPARQL >>>>> over SQL databases. One of the motivators for the SemWeb is that we >>> get to >>>>> connect everything to everything, including e.g. sets of SQL DBs. The >>>>> relational world has some tooling for the latter case, e.g. "Oracle >>>>> Database Streams" and "SQL Server Integration Services". What do y'all >>> know >>>>> about them? It could help some audience members if I were able to >>> contrast >>>>> existing SQL tooling against SPARQL over DB-backed RDF graphs. >>>>> >>>>> -- >>>>> -ericP >>>>> >>>>> >>> >>> -- >>> -ericP >>> > > -- > -ericP >
Received on Monday, 13 February 2012 23:28:51 UTC