The query-language “VAMDC SQL Sub-set 1” (VSS1) was defined. This language was the only one formally supported by VAMDC data-services in the 11.05 release of the system.
No new version of the standard was issued for this system release, but informal support for a new query language, VSS2, was implemented in some nodes.
VSS2 is VAMDC SQL Sub-set 2 and is a super-set of VSS1. Nodes that can process VSS2 queries can process VSS1 queries using the same code.
The features in VSS2 but not in VSS1 are:
VSS2 was formally defined. Its specification document is independent of that for VSS1, even though the two languages are related.
The prefices on restrictables were changed. “Upper” and “lower” replaced “initial” and “final”.
In v11.12 of the system, VAMDC nodes are expected to accept either VSS1 or VSS2.
VSS1 query language becomes obsolete, all nodes must support VSS2 queries now.
VSS2 specification stays unchanged. More keywords for restrictables and requestables are defined in VAMDC dictionary document