Note: The time it typically takes to run each query and the # of objects found (in runs 752/756) is indicated in the comments below the query. The estimated time according to the query analysis (cost prediction) is also indicated in parentheses. The actual time will depend on a number of factors such as the system load and the number and type of SELECT fields in the query.
// Paula Szkody <szkody@alicar.astro.washington.edu>
// Search for Cataclysmic Variables and pre-CVs with White Dwarfs and
// very late secondaries:
// u-g < 0.4
// g-r < 0.7
// r-i > 0.4
// i-z > 0.4
SELECT obj.field.segment.run,
obj.field.segment.camCol,
obj.field.segment.rerun,
obj.field.field,
obj.objID,
u,g,r,i,z,
obj.ra, obj.dec
FROM sxPrimary
WHERE (
u - g < 0.4 &&
g - r < 0.7 &&
r - i > 0.4 &&
i - z > 0.4
)
// Simple enough, but note that we run it on sxPrimary, a subclass of sxTag
// that includes sxGalaxy, sxStar, sxSky and sxUnknown. This excludes the
// sxBad and sxSecondary classes which need not be searched. Object
// members are extracted using the "obj" association-link in the tag class.
// Runs in 1438s (est 1566) and finds 83969 objs.
// (Robert H. Lupton <rhl@astro.princeton.edu>)
SELECT field.segment.run,
field.segment.camCol,
field.field,
objID,
objRowc,objColc,rowv,colv,rowvErr,colvErr,
objFlags,flags,psfCounts,psfCountsErr
FROM sxPhotoPrimary
WHERE (
((rowv * rowv) / (rowvErr * rowvErr) +
(colv * colv) / (colvErr * colvErr) > 4)
)
// Runs in 977s (est. 132) and finds 298882 objs.
// (Robert H. Lupton <rhl@astro.princeton.edu>)
// coordinate cut --> cut in ra --> 40:100
SELECT tag.g, tag.r
FROM sxPhotoObj
WHERE (
((-0.642788 * tag.cx + 0.766044 * tag.cy>=0) AND
(-0.984808 * tag.cx - 0.173648 * tag.cy<0))
)
// This query currently returns an empty query execution tree, i.e.
// no nodes are found to satisfy this cut.
// Another coordinate cut:
SELECT psfCounts, rowv, colv, id, field.field,
field.segment.run,field.segment.camCol
FROM sxPhotoObj
WHERE (
((-0.707107 * tag.cx -0.707107 * tag.cy>=0) AND
(-0.694658 * tag.cx -0.71934 * tag.cy<0))
)
// This one runs in 162s (est 90) but finds 0 objs.
// (Robert H. Lupton <rhl@astro.princeton.edu>)
// Searching for a particular object in a particular field.
SELECT objID,
field.field, ra, dec
FROM sxPhotoObj
WHERE (
objID = 14 && field.field = 11
)
// Runs in s (est ).
// Michael Strauss <strauss@astro.princeton.edu>
// For all galaxies with r_Petro < 18, not saturated, not bright, not
// edge, give me those whose centers are appreciably bluer than their
// outer parts. That is, define the center color as: u_psf - g_psf And
// define the outer color as: u_model - g_model Give me all objects
// which have (u_model - g_model) - (u_psf - g_psf) < -0.4
SELECT u,g,photoobj.objID // or whatever you want from each object
FROM sxGalaxy
WHERE (
(flag1 & (OBJECT1_SATUR | OBJECT1_BRIGHT | OBJECT1_EDGE) == 0) &&
(photoobj.petroRad[2] < 18) &&
(((photoobj.modelCounts[0] - photoobj.modelCounts[1]) -
(photoobj.psfCounts[0] - photoobj.psfCounts[1])) < -0.4)
)
// Notes: r_Petro -> petroRad[2] (3rd element of ugriz array) u_psf,
// g_psf -> psfCounts[0], psfCounts[1] u_model, g_model ->
// modelCounts[0], modelCounts[1] ** these are the same as ugriz, so
// if you can use (u-g) instead of (modelCounts[0] - modelCounts[1])
// it runs twice as fast! The search is performed on the sxGalaxy
// subclass of sxTag, so only galaxy objects are searched and you dont
// need the "if galaxy..." The petroRad, modelCounts and psfCounts
// are members of the sxPhotoObj class, which is accessed via the
// "photoobj" association link in the tag class. Since the query is
// done on tag objects, you need the "photoobj." prepended to each
// photoobj member in the SELECT list. A combination of flags is used
// to filter out saturated, bright and edge objects.
//
// Runs in 598s (est. 643) and finds 23737 objs (using u-g).
// Michael Strauss <strauss@astro.princeton.edu>
// Give me the PSF colors of all stars brighter than 20th (rejecting on
// various flags) that have PSP_STATUS = 2
//
// This query can be formulated in at least 2 ways, but the second
// being much faster than the first:
// Method 1:
SELECT photoobj.psfCounts, // or whatever you want from each object
field.segment.run,
field.segment.camCol,
field.segment.rerun,
field.field
FROM sxStar
WHERE (
obj.psfCounts[1] < 20 && (field.pspStatus = 2)
)
// The search is performed on the sxStar subclass of sxTag, so only
// star objects are searched.
// PSP_STATUS -> field.pspStatus
// Runs in 727s (est. 918) but finds 0 objs. [ART]
// Finds tons of objects if pspStatus check is left out.
// Method 2 (this is an example of an association query):
SELECT field.segment.run,
field.segment.camCol,
field.segment.rerun,
field.field,
objID,ra,dec
FROM (
SELECT obj FROM field WHERE pspStatus = 2
)
WHERE (
objType = AR_OBJECT_TYPE_STAR && psfCounts[2] < 20
)
// The second query uses the knowledge that there are far fewer fields than
// objects, and so drastically narrows the number of objects found by using
// an association query on the field class. We first get all objects
// belonging to fields with pspStatus = 2, then apply the star test and
// psfCounts predicate to all such objects.
// Runs in < 2s (est 10) and finds 0 objs (FAST!).
// (James Annis <annis@fnal.gov>)
// if {AR_DFLAG_BINNED1 || AR_DFLAG_BINNED2 || AR_DFLAG_BINNED4} {
// if {! ( AR_DFLAG_BLENDED && !( AR_DFLAG_NODEBLEND || AR_DFLAG_CHILD))} {
// if { galaxy } { ;# not star, asteroid, or bright
// if { primary_object} {
// if {petrocounts{i} < 23 } { accept }
// }
// }
// }
// }
SELECT obj.field.segment.run, // or whatever you want
obj.field.segment.camCol,
obj.field.segment.rerun,
obj.field.field,
obj.objID, obj.ra, obj.dec
FROM galaxy // select galaxy and primary only
WHERE (
flag1 & (AR_DFLAG1_BINNED1 | AR_DFLAG1_BINNED2 | AR_DFLAG1_BINNED4) > 0
&&
flag1 & (AR_DFLAG1_BLENDED | AR_DFLAG1_NODEBLEND | AR_DFLAG1_CHILD) !=
AR_DFLAG1_BLENDED
&&
obj.petroCounts[3] < 23
)
// Notes: AR_DFLAG -> AR_DFLAG1 or OBJECT1
// petrocounts -> petroCounts[3] (i is 4th in array[0:4] of u,g,r,i,z)
// Selecting sxGalaxy (or galaxy) class already ensures it is a primary
// object because sxGalaxy is a subclass of sxPrimary.
// The petroCounts is a member of the sxPhotoObj class, which is accessed
// via the "photoobj" (alias "obj") association link in the tag class.
//
// Takes almost an hour to run and finds almost all of the 1.9M galaxies!
// (James Annis <annis@fnal.gov>)
// if {AR_DFLAG_BINNED1 || AR_DFLAG_BINNED2 || AR_DFLAG_BINNED4} {
// if {! ( AR_DFLAG_BLENDED && !( AR_DFLAG_NODEBLEND || AR_DFLAG_CHILD)} {
// if { galaxy } { ;# not star, asteroid, or bright
// if (!AR_DFLAG_NOPETRO) {
// if { petrorad > 15 } { accept }
// } else {
// if { petror50 > 7.5 } { accept }
// }
// if (AR_DFLAG_TOO_LARGE && petrorad > 2.5 ) { accept }
// if ( AR_DFLAG_SATUR && petrorad < 17.5) { don't accept }
// }
// }
// }
SELECT obj.field.segment.run,
obj.field.segment.camCol,
obj.field.segment.rerun,
obj.field.field,
obj.objID, obj.ra, obj.dec
FROM galaxy
WHERE (
flag1 & (AR_DFLAG1_BINNED1 | AR_DFLAG1_BINNED2 | AR_DFLAG1_BINNED4) > 0
&&
flag1 & (AR_DFLAG1_BLENDED | AR_DFLAG1_NODEBLEND | AR_DFLAG1_CHILD) !=
AR_DFLAG1_BLENDED
&&
( ( flag1 & AR_DFLAG1_NOPETRO == 0 && obj.petroRad[3] > 15 ) ||
( flag1 & AR_DFLAG1_NOPETRO > 0 && obj.petroR50[3] > 7.5 ) )
||
( flag1 & AR_DFLAG1_TOO_LARGE >0 && obj.petroRad[3] > 2.5 )
&&
( flag1 & AR_DFLAG1_SATUR == 0 || obj.petroRad[3] >= 17.5 )
)
// Notes: AR_DFLAG -> AR_DFLAG1 or OBJECT1
// petrorad -> petroRad[3] (i is 4th in array[0:4] of u,g,r,i,z)
// petror50 -> petroR50[3] similarly
// The search is performed on the sxGalaxy (alias "galaxy") subclass of
// sxTag, so only galaxy objects are searched.
// The petrorad and petroR50 are members of the sxPhotoObj class, which
// is accessed via the "photoobj" (alias "obj") association link in
// the tag class.
// Runs in 790s (est 643) and returns 11065 objs. Jim thinks that this is too
// many objects, and we are investigating whether we formulated the query
// as he intended it or not. Same is the case for the next two queries.
// (James Annis <annis@fnal.gov>)
// if {AR_DFLAG_BINNED1 || AR_DFLAG_BINNED2 || AR_DFLAG_BINNED4} {
// if {! ( AR_DFLAG_BLENDED && !( AR_DFLAG_NODEBLEND || AR_DFLAG_CHILD)} {
// if { galaxy } { ;# not star, asteroid, or bright
// if { primary_object} {
// if {!AR_DFLAG_CR && !R_DFLAG_INTERP}
// if { frame_seeing < 1.5" } {
// if { counts_model<i>-counts_model<z> -
// (reddening<i> - reddening<z>) > 1.0 } {
// accept
// }
// }
// }
// }
// }
// }
// }
SELECT field.segment.run,
field.segment.camCol,
field.segment.rerun,
field.field,
obj.objID, obj.ra, obj.dec
FROM galaxy
WHERE (
flag1 & (AR_DFLAG1_BINNED1 | AR_DFLAG1_BINNED2 | AR_DFLAG1_BINNED4) > 0
&&
flag1 & (AR_DFLAG1_BLENDED | AR_DFLAG1_NODEBLEND | AR_DFLAG1_CHILD) !=
AR_DFLAG1_BLENDED
&&
flag1 & (AR_DFLAG1_CR | AR_DFLAG1_INTERP) == 0
&&
field.psfWidth[2] < 1.5
&&
(i - z - (obj.reddening[3] - obj.reddening[4]) > 1.0 )
)
// i - z used inst. of modelCounts<i> - modelCounts<z>
// Runs in 1043s (est 643), finds 29648 objects.
{
// (James Annis <annis@fnal.gov>)
// if {AR_DFLAG_BINNED1 || AR_DFLAG_BINNED2 || AR_DFLAG_BINNED4} {
// if {! ( AR_DFLAG_BLENDED && !( AR_DFLAG_NODEBLEND || AR_DFLAG_CHILD)} {
// if {!AR_DFLAG_EDGE & !AR_DFLAG_SATUR} {
// if { galaxy} { ;# not star, asteroid, or bright
// if { primary_object} {
// if {! (petrocounts<2> < 15.5 && petror50<2> < 2) } {
// if {petrocounts<r> > 0 && counts_model<g> > 0 &&
// counts_model<r> > 0 && counts_model<i> > 0 } {
// petSB = deRed_r + 2.5*log10(2*3.1415*petror50<r>^2)
// deRed_g = petrocounts<g> - reddening<g>
// deRed_r = petrocounts<r> - reddening<r>
// deRed_i = petrocounts<i> - reddening<i>
// deRed_gr = deRed_g - deRed_r
// deRed_ri = deRed_r - deRed_i
// cperp = deRed_ri - deRed_gr/4.0 - 0.18
// cpar = 0.7*deRed_gr + 1.2*(deRed_ri -0.18)
// if {(deRed_r < 19.2 && deRed_r < 13.1 + cpar/0.3 &&
// abs(cperp) < 0.2 && petSB < 24.2 ) ||
// (deRed_r < 19.5 && cperp > 0.45 - deRed_gr/0.25 &&
// deRed_gr > 1.35 + deRed_ri*0.25 && petSB < 23.3) {
// accept ;# whew!!!
// }
// }
// }
// }
// }
// }
// }
// }
//
SELECT
field.segment.run,
field.segment.camCol,
field.segment.rerun,
field.field,
obj.objID,
obj.ra,
obj.dec
FROM galaxy WHERE (
flag1 & (AR_DFLAG1_BINNED1 | AR_DFLAG1_BINNED2 | AR_DFLAG1_BINNED4) > 0 &&
flag1 & (AR_DFLAG1_BLENDED | AR_DFLAG1_NODEBLEND | AR_DFLAG1_CHILD) !=
AR_DFLAG1_BLENDED &&
flag1 & (AR_DFLAG1_EDGE | AR_DFLAG1_SATUR) == 0 &&
obj.petroCounts[3] > 17.65 &&
(obj.petroCounts[2] > 15.5 || obj.petroR50[2] > 2 ) &&
(obj.petroCounts[2] > 0 && g > 0 && r > 0 && i > 0 ) &&
(
(obj.petroCounts[2] - obj.reddening[2] < 19.2) &&
(obj.petroCounts[2] - obj.reddening[2] < 13.1 + // deRed_r < 13.1 +
(7/3)*( g - obj.reddening[1] - // 0.7 / 0.3 * deRed_gr
r + obj.reddening[2] ) +
4 *( r - obj.reddening[2] - // 1.2 / 0.3 * deRed_ri
i + obj.reddening[3] )
-4 * 0.18 ) &&
( ( r - obj.reddening[2] -
i + obj.reddening[3] -
(g - obj.reddening[1] -
r + obj.reddening[2])/4 - 0.18 ) < 0.2 ) &&
( ( r - obj.reddening[2] -
i + obj.reddening[3] -
(g - obj.reddening[1] -
r + obj.reddening[2])/4 - 0.18 ) > -0.2 ) &&
// petSB - deRed_r + 2.5 log10(2Pi*petroR50^2)
( (obj.petroCounts[2] - obj.reddening[2]) +
2.5 * LOG( 2 * 3.1415 * obj.petroR50[2] * obj.petroR50[2] ) < 24.2 )
) ||
(
(obj.petroCounts[2] - obj.reddening[2] < 19.5) &&
( ( r - obj.reddening[2] - // cperp = deRed_ri
i + obj.reddening[3] - // - deRed_gr/4 - 0.18
(g - obj.reddening[1] -
r + obj.reddening[2])/4 - 0.18 ) >
0.45 - 4*( g - obj.reddening[1] - // 0.45 - deRed_gr/0.25
r + obj.reddening[2] ) ) &&
( g - obj.reddening[1] -
r + obj.reddening[2] >
1.35 + 0.25 *( r - obj.reddening[2] -
i + obj.reddening[3] ) ) &&
// petSB - deRed_r + 2.5 log10(2Pi*petroR50^2)
( (obj.petroCounts[2] - obj.reddening[2]) +
2.5 * LOG( 2 * 3.1415 * obj.petroR50[2] * obj.petroR50[2] ) < 23.3 )
)
)
// query runs in 2035 seconds, returning 19942 objects.
// after having added the obj.petrocounts[3] > 17.65, there are
// still 16944 objects.
// Gordon Richards <richards@oddjob.uchicago.edu>
// Low-z QSO candidates using the following cuts:
//
// -0.27 <= u-g < 0.71
// -0.24 <= g-r < 0.35
// -0.27 <= r-i < 0.57
// -0.35 <= i-z < 0.70
// g <= 22
// objc_type == 3
SELECT g,obj.objID // or whatever you want returned
FROM sxGalaxy // takes care of objc_type == 3
WHERE (
(g <= 22) &&
(u-g >= -0.27) && (u-g < 0.71) &&
(g-r >= -0.24) && (g-r < 0.35) &&
(r-i >= -0.27) && (r-i < 0.57) &&
(i-z >= -0.35) && (i-z < 0.70)
)
//
// Runs in 323s (est. 643) and finds 12054 objs.
// OR, do it using the BETWEEN operator:
SELECT field.segment.run,
field.segment.camCol,
field.segment.rerun,
field.field,
obj.objID,
obj.ra,
obj.dec
FROM sxGalaxy
WHERE
g <= 22 &&
(u-g) BETWEEN -0.27 AND 0.71 &&
(g-r) BETWEEN -0.24 AND 0.35 &&
(r-i) BETWEEN -0.27 AND 0.57 &&
(i-z) BETWEEN -0.35 AND 0.70
// This runs in 11:41 minutes and returns 12054 objects. The longer
// time is due to the additional association links it has to follow up
// in the SELECT statement. The more member fields you want to extract
// and the more indirection is involved (i.e. association of
// association of ...), the longer it will take to get the results
// back. As for the second part of this query: Then I look to see if
// any of the output objects are within 10" of each other to see if
// they might be gravitational lens candidates. For output, I spit out
// run, rerun, camcol, field, id, g', the 4 colors, and the FIRST peak
// flux.
Comment: This would have to be done with an analysis engine. There is no way to do this with the SX currently (although you can do a proximity query on a single object at a time).
// Gordon Richards <richards@oddjob.uchicago.edu>
// Another useful query is to see if the errors on moving (or apparently
// moving objects) are correct. For example it used to be that some
// known QSOs were being flagged as moving objects. One way to look for
// such objects is to compare the velocity to the error in velocity and
// see if the "OBJECT1_MOVED" or "OBJECT2_BAD_MOVING_FIT" is set. So
// return objects with
//
// objc_type == 3
// sqrt(rowv*rowv + colv*colv) >= sqrt(rowvErr*rowvErr + colvErr*colvErr)
//
// then output, the velocity, velocity errors, i' magnitude, and the
// relevant "MOVING" object flags.
SELECT obj.rowv,
obj.colv,
obj.rowvErr,
obj.colvErr,
i,
flag1 & OBJECT1_OBJECT_MOVED,
flag2 & OBJECT2_BAD_MOVING_FIT
FROM sxGalaxy
WHERE (
(flag1 & OBJECT1_OBJECT_MOVED) > 0 || (flag2 & OBJECT2_BAD_MOVING_FIT) > 0 &&
(obj.rowv * obj.rowv + obj.colv * obj.colv) >= (obj.rowvErr * obj.rowvErr
+ obj.colvErr * obj.colvErr)
)
// Runs in 1615s (est. 643) and finds 72987 objs with flags.
// Karl Glazebrook <kgb@pha.jhu.edu>
// So as a newcomer I might want to do somethink like 'give me the colours
// of 100,000 random objects from all fields which are survey quality' so
// then I could plot up colour-colour diagrams and play around with
// more sophisticated cuts. How would I do that?
//
// COMMENT:
// Unfortunately, it is not possible to get a random sample using the SX (yet).
// One thing you might do is get all the objects in a given database file
// in the federation. There are currently ~ 200 DBs in the SX, and getting
// all the objects in one DB wd give you several thousand objects, though
// all in a given region of the sky. To have a sample you might also just
// select a certain run and camcol and investigate only the galaxies from
// there:
SELECT * FROM (
SELECT obj FROM field WHERE segment.run = 752 && segment.camcol = 2
) WHERE objType = 3
// (Dan VandenBerk <danvb@fnal.gov>) // We have a list of objects -- RA and DEC -- for which we would like // matches and all of the tsObj data. Can I send you the list?
This can be run using the ProxList server to process the datafile one by one. See section on proxlist for details.
// (Xiaohui Fan et.al. <fan@astro.princeton.edu>)
// quasar finding query
SELECT obj.field.segment.run,
obj.field.segment.camCol,
obj.field.segment.rerun,
obj.field.field,
obj.objID,
u,g,r,i,z,
obj.ra,
obj.dec
FROM sxStar // or sxGalaxy
WHERE (
( u - g > 2.0 || u > 22.3 ) &&
( i < 19 ) && ( i > 0 ) &&
( g - r > 1.0 ) &&
( r - i < 0.08 + 0.42 * (g - r - 0.96) || g - r > 2.26 ) &&
( i - z < 0.25 )
)
