On 05/08/13 02:21, Holger Knublauch wrote:
On 8/3/2013 9:50, Rob Vesse wrote:
Side Note - Initial bindings for updates was removed because it
was a barrier to streaming updates
(http://markmail.org/message/bazwh2exmcc5vmoh). Also as others
noted in the discussion there initial bindings is a little murkier
for updates since does it apply only to WHERE clauses, to all
portions of requests, etc? Keeping the API as-is is always an
option, if this ends up being the preference of the community then
we definitely need to improve the documentation to note that there
can be unintended interactions with other parts of the query
engine such as the optimizer when initial bindings are used.
Yet I believe the handling of this removal for UPDATEs was a bit
rushed. I don't have the whole background, so apologies if I miss
something obvious, but it sounds like there was no real deprecation
cycle because it would have complicated some *modes* of using
UPDATEs (streaming, remote). However, these are just some modes among
others, and it might have been possible to document it away for those
modes, and throw an exception if someone uses a streaming update
with initial bindings. Right now the API is inconsistent because
bindings are still present for Queries, and all our usages of initial
bindings with UPDATEs would have continued to work. We were
unfortunately unable to upgrade to newer Jena versions earlier,
because there have been some other show stopper bugs in the code. I
am using the SNAPSHOT now to try to detect those before a release,
and may have more reports in the next couple of days as I run through
manual and automated test scenarios.
The most important and obvious use case (IMO) is insert-data:
INSERT DATA { ?s rds:label "foo" }
but that is illegal syntax in strict SPARQL 1.1 so this use case does
not work in the initial bindings paradigm. (Yes - we would can change
the parser and do the "DATA is all data" check later. It would fail WG
tests of syntax).
How does TopQuadrant use initial bindings with update? Please give some
concrete examples.
Andy
Thanks Holger
