TAP-1_0-Err-5 < IVOA

---+ TAP-1.0 Erratum 5: VOTable usage in TAP

Author: DAL WG

Date last changed: 2017-09-28

---++ Rationale

The wording in [[http://www.ivoa.net/documents/TAP/20100327/index.html][TAP-1.0]] in §~2.9 and §2.9.1 about the use of [[http://www.ivoa.net/documents/VOTable/][VOTable]] is somewhat inconsistent about the format of VOTable error documents. 
It is clear that §2.9 is discussing both successful and error outputs, and in the case of an error no =TABLE= element will normally be present, only one or more =INFO= elements. However, while the intention is clear from the fourth example in §2.9.1, it is not clear from the wording.

---++ Erratum Content

The wording of §2.9 and §2.9.1 of TAP-1.0 is inconsistent with the rules for VOTable error documents. §2.9 says 
<dl>
  <dd>The VOTable must contain a =RESOURCE= element identified with the attribute =type='results'=, containing a single =TABLE= element with the results of the query.</dd>
</dl>
and §2.9.1 says
<dl>
  <dd>The =RESOURCE= element must contain, before the =TABLE= element, ...</dd>
</dl>
The inconsistency comes from the fact that in case of a response error no =TABLE= element will normally be present, only one or more =INFO= elements.

This Erratum removes the inconsistency by changing:
   * first sentence in the third paragraph of Sec.~2.9 from
<dl>
  <dd>The VOTable must contain a RESOURCE element identified with the attribute type="results", containing a single TABLE element with the results of the query.</dd>
</dl>
to
<dl>
  <dd>The VOTable must contain a =RESOURCE= element identified with the attribute =type='results'=type='results'.  In case of successful job execution,
   this must contain exactly one TABLE element with the results of
   the query. [In case of job failure, the TABLE element may be absent.]</dd>
</dl>
   * first paragraph of §2.9.1 from
<dl>
  <dd>The =RESOURCE= element must contain, before the =TABLE= element, an =INFO= element with attribute =name="QUERY_STATUS"=. The value attribute must contain one of the following values:</dd>
</dl>
to
<dl>
  <dd>The =RESOURCE= element must contain an =INFO= element with attribute =name="QUERY_STATUS"= indicating the success of the operation. For =RESOURCE= elements that contain a =TABLE= element, this =INFO= element must appear lexically before the =TABLE=. The following values are defined for this =INFO= element's =value= attribute:</dd>
</dl>

---++ Impact Assessment

Since the wording changes introduced by this Erratum are only meant to better describe the usage of an existing recommendation (the VOTable one) inside the TAP-1.0 protocol, no effects on TAP-1.0 services and consuming application is foreseen.

---++ Note

This Erratum was previously part of the !TAP1Err1 Note still available on [[http://volute.g-vo.org/svn/trunk/projects/dal/TAP1Err1/][volute]]. The content presented here started from §6 of that Note at svn revision 2800.

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This topic: IVOA > WebHome > IvoaDAL > TableAccess > TAP-1_0-Errata > TAP-1_0-Err-5
Topic revision: r3 - 2017-09-27 - MarcoMolinaro