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TAP Standards and FeedbackDeoyani Nandrekar-HeinisJohns Hopkins University

April 22, 2023Deoyani Nandrekar-Heinis, JHU

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Points of Discussion

Upload tables Authentication VOSpace integration ADQL and spatial queries Other issues


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Upload Tables

Scope of tables Life of uploaded table Access Usage and query edit


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Authentication

Upload access to only authorized user User query and result access


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VOSpace Integration

Store results in user’s vospace Store job.xml and result in vospace


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ADQL and Spatial Queries

Generic Queries? Spatial constraints

e.g. Using HTM ids Complex Queries Parsing Difficulties Suggestions and Options


ADQL Example7

• ADQL (Spatial)

SELECT o.ra, o.dec FROM photoobjall as o WHERE CONTAINS( POINT('J2000', o.ra, o.dec), Region('CIRCLE J2000 180 0 0.3')) = 1

• SDSS SQL Query:

Select o.ra, o.dec From photoobjAll as o inner join dbo.fSphGetHtmRanges(dbo.fSphSimplifyString('CIRCLE J2000 180 0 0.3')) h on o.HtmID between h.HtmIdStart and h.HtmIdEnd Where dbo.fSphRegionContainsXYZ(dbo.fSphSimplifyString('CIRCLE J2000 180 0 0.3'), o.cx ,o.cy,o.cz) = 1


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SELECT a.objid, a.ra, a.dec, b.objid, b.ra, b.dec FROM CatalogA AS a INNER JOIN CatalogB AS b ON CONTAINS(CIRCLE(a.ra, a.dec, 0.1), POIN T(b.ra, b.dec)) WHERE (some condition)

circle has to be calculated for every row in A in order to evaluate the query

HTM based optimization (not sufficient?) Solution::

temporary tables, generate the HTM ranges, put an index on them and then do the BETWEEN query.


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CREATE TABLE ##htmtemp (ObjID bigint, HtmStart bigint, HtmEnd bigint) -- +

create the indices here: PK on ObjID, cover index on HtmStart/End INSERT ##htmtemp WITH (TABLOCK) (ObjID, HtmStart, HtmEnd) SELECT ObjID, htm.Start, htm.End FROM CatalogA CROSS APPLY dbo.fHtmCoverCircleEq(Ra, Dec, 0.1) AS htm

SELECT a.objid, a.ra, a.dec, b.objid, b.ra, b.dec FROM CatalogA AS a

INNER JOIN ##htmtemp htm ON htm.ObjID = a.ObjID INNER JOIN CatalogB AS b

ON dbo.fGetHtmEq(b.Ra, B.Dec) BETWEEN htm.HtmStart AND htm.HtmEnd WHERE ...


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CREATE TABLE ##htmtemp (ObjID bigint, HtmStart bigint, HtmEnd bigint) -- +

create the indices here: PK on ObjID, cover index on HtmStart/End INSERT ##htmtemp WITH (TABLOCK) (ObjID, HtmStart, HtmEnd) SELECT ObjID, htm.Start, htm.End FROM CatalogA CROSS APPLY dbo.fHtmCoverCircleEq(Ra, Dec, 0.1) AS htm

SELECT a.objid, a.ra, a.dec, b.objid, b.ra, b.dec FROM CatalogA AS a

INNER JOIN ##htmtemp htm ON htm.ObjID = a.ObjID INNER JOIN CatalogB AS b

ON dbo.fGetHtmEq(b.Ra, B.Dec) BETWEEN htm.HtmStart AND htm.HtmEnd WHERE ...

Multiway joins are

slow!!


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Special Spatial

Objects bright in Optical and invisible in UV Query:

SELECT ...FROM SDSS AS a INNER JOIN Galex AS b ON NOT CONTAINS(CIRCLE(a.ra, a.dec, 0.1), POINT(b.ra, b.dec))

Ugly where clauses

WHERE CONTAINS(CIRCLE(POINT(a.ra, a.dec), 0.5), POINT(b.ra, b.dec) OR CONTAINS(CIRCLE(POINT(a.ra + 0.2, a.dec + 0.2), 0.5), POINT(b.ra,b.dec)

• Multiple conditions where clause

WHERE CONTAINS(CIRCLE(POINT(a.ra, a.dec), 0.5),

POINT(b.ra, b.dec) AND type= galaxy OR CONTAINS(CIRCLE(POINT(a.ra, a.dec), 0.5), POINT(b.ra, b.dec) AND type= star


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Suggestions

Spatial region: only constant values

Spatial constraints: Outside where clause

CROSS MATCH : handling separately


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