Asynchronous querying and tabular data

Patrick Dowler patrick.dowler at
Wed May 2 12:22:50 PDT 2007

On Wednesday 02 May 2007 11:07, Doug Tody wrote:
> A single service could support both: queryData for synchronous DM and
> ADQL-based queries, and optionally stageData for asyn/staged execution.
> The client would then either have to guess which to use, or try a
> few smaller synchronous queries first to determine what to do, and
> then resubmit a larger query as a batch job.

I said earlier that I think this is what we need (single step sync and async 
querying methods). For what it's worth, I think they both need the word query 
in the name, for the simple reason that this is what people new to the API 
will look for. For example, when you first learn the JDBC API, you poke 
around aimlessly until you find the Statement interface and the method:

ResultSet executeQuery(String sql)

That is where you start. Then you learn about Connection and DriverManager 
(maybe DataSource) and ResultSet... but you grok it when you see that one 
method signature. 

** I think it is really important for TAP to have this kind of very clear 
focal point.  **

PS-Sure, JDBC is a nightmare of bad design otherwise, but once someone finds 
that method signature they can proceed from there and get something working 
quite quickly.


Patrick Dowler
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