UtypesTigerTeamMinTel13 < IVOA

IVOA Web>WebPreferences>UtypesTigerTeam>UtypesTigerTeamMinTel13 (2021-04-13, GiuliaIafrate) (raw view)

WYSIWYG content - do not remove this comment, and never use this identical text in your topics
---+ Utypes Tiger Team, Minutes of 2013-03-26

Present: Jesus, Gerard, Omar, Markus, Mirielle, Pat

<br />OL described pure vs path utypes: pure is an identifier in a vo-dml document and path is (a path?) in an instance document (derived from pure, but not unique)<br /><br />ML: What is the difference betwen a DM instance and a VOTable serialisation?<br /><br />MD,GL: yes, the things in the VOTable are instances<br /><br />OL: brought up SED/phot example w/ columns<br /><br />GL: ML proposed a comprimise utype solution<br /> <br />ML: utype per field (path utype), then annotate the structure with the vo-dml (pure) utypes - can reconstruct the class structure<br /><br />ML/GL/MD: path utypes for fields and and pure utypes for refs (eg VOTable GROUPs) <br /><br />MD: we should just pick one type -- if everyone else agrees it has to be pure, so be it (but that would exclude some applications that may be in scope)<br /><br />OL: need either (parseable) path or groups (pure?), not both<br /><br />GL: groups with field refs<br /><br />OL: didn't really see them as two alternatives, utypes are still strings (opaque labels)<br /><br />GL: can only be opaque if you can look them up somewhere so pure is opaque with a prefix to tell you where to look them up<br /><br />GL: can generate all possible path (utypes) for a model<br /><br />JS: for PhotDMv1-1, have to add vo-dml utypes (aliases?)<br /><br />GL: list of utypes, but also need rules on how to use them (e.g. inside VOTable)<br /><br />??: use path utypes but still require groups and pure utypes?<br /><br />JS: "should do it" (groups)<br /><br />ML: cannot force people to use groups (burden on providers to organise content according to models)<br /><br />OL: but this should all be easier with pure utypes!<br /><br />JS: (comment I didn't catch)<br /><br />GL: (clients) should be capable of parsing and hndling groups if they are parsing a VOTable<br /><br />JS: if ou have the path utypesm you can (do simple stuff esily)<br /><br />GL: path "seems" simpler than navigating groups, but is it actually that much better (simpler)?<br /><br />MD: for VOTable, pure and path are ~equivalent<br />GL: *not true* paths lose some information which I describe in the text about "casting"<br /><br />MD: actually want path utypes for non-VOTable applications (key-value?)<br /><br />GL: possible to add GROUPs to TAP? TAP_SCHEMA? VOSI-Tables? Is empty (metadata) VOTable an option? <br />PD: in TAP_SCHEMA you would have potential for recursive joins in a tap_schema.groups table to mirror the recursive groups<br />PD/MD: VOSI-Tables would touch VODataService which is widely used so thats messy<br />PD: metadata VOTable is already available with a MAXREC=0, but requires a QUERY; some metadata is only vailable that way already<br /><br />GL: casting (type vs role?)<br /><br />GL: are changes to VOTable on the table? :-)<br />all: no one seemed too enthusiastic<br /><br />OL: summary -- pure utypes for fieldrefs and path utypes for fields<br />OL: if they are not mandatory it may be useless (too few people will include them)<br /><br />JS: consider path utypes as aliases you can look up<br /><br />OL: what should be required? optional? -- can't answer this question yet<br /><br />ACTION on GL: write up a side-by-side comparison of 3 kinds of uses (1-2 pages?)<br /><br />Next telecon: 2013-04-12T16:00:00 -- that's IVOA standard timestamp string, so 1600 UTC!

-- IVOA.PatrickDowler - 2013-03-28

<!--
      * Set ALLOWTOPICRENAME = IVOA.TWikiAdminGroup
-->

Topic revision: r4 - 2021-04-13 - GiuliaIafrate

IVOA

Log in or Register

IVOA.net
Wiki Home
WebChanges
WebTopicList
WebStatistics

Twiki Meta & Help
IVOA
Know
Main
Sandbox
TWiki

TWiki intro
TWiki tutorial
User registration
Notify me

Working Groups

Interest Groups

Time Domain

Committees

Stds&Procs

www.ivoa.net
Documents
Events
Members
XML Schema