SkyServer: Table Descriptions

name type text

Best2Sector Geometry This table places the Best photometric objects into sectors, which are used to divide the sky into geometric regions. Each object appears once, and only once, in this table because a given ra and dec belong to a unique sector.

Chunk Geometry This table contains some very basic information for each chunk loaded in the database.

Convex Geometry

CoordType Meta This view contains the CoordType enumerated values from DataConstants as integers.

DataConstants Meta The table DataConstants contains most of the bit-flags and enumerated quantities relevant to the SDSS. DO NOT confuse this with SDSSConstants, which contains actual constants used in data processing.

DBColumns Meta This table contains an extremely brief description of every column in every table in the database. Because some quantities appear in multiple tables with multiple meanings, a quantity is uniquely defined only within a single table.

DBObjectDescription Meta This table contains the long descriptions for every table and view in the database.

DBObjects Meta This table contains names and descriptions of all the tables and views in the database.

DBViewCols Meta This table stores the names and descriptions of all columns in all views in the database. This is used by the auto-documentation.

ELRedShift Spectro This table contains ALL of the measured emission lines, along with their redshifts and related information, for ALL spectroscopic objects.

Field Meta This table contains all the measured parameters of each imaging field, along with relevant summary statistics, and astrometric and photometric information.

FieldMask Meta This view contains the FieldMask flag values from DataConstants as binary(4).

FieldProfile Photo Need description.

FieldQuality Meta This view contains the FieldQuality enumerated values from DataConstants as integers.

First External This table stores measurements from the FIRST radio survey for those FIRST objects which are matched to SDSS photometric objects. ????

Frame Photo This table actually contains false color JPEG images of the fields, and their most relevant parameters, in particular the coefficients of the astrometric transformation, and position info. The images are stored at several zoom levels.

FramesStatus Meta This view contains the FramesStatus enumerated values from DataConstants as integers.

Galaxy Photo This view contains only those primary photometric objects classified as galaxies. As such, it is a view of PhotoPrimary, which is itself a view of PhotoObjAll.

HoleObj Spectro This table stores information for non-OBJECT holes on spectroscopic plates, and for OBJECT holes that were not mapped by the fiber mapper.

HoleType Meta This view contains the HoleType enumerated values from DataConstants as integers.

ImageMask Meta This view contains the ImageMask flag values from DataConstants as binary(2).

InsideMask Meta This view contains the InsideMask flag values from DataConstants as binary(1).

Mask Geometry This table contains information about each photometric mask.

MaskedObject Geometry This is a list of all masked photometric objects. These objects were detected but are within the boundaries of a masked area (see the Mask table) and thus unreliable. Each object may appear multiple times, if it is masked for multiple reasons.

MaskType Meta This view contains the MaskType enumerated values from DataConstants as integers.

Match Photo This table contains pairs of photometric objects from different runs (times) that probably are the same object. These must be SDSS primary or secondary objects, of type STAR, GALAXY, and UNKNOWN, within 1 arcsec of one another, and from different runs. The table also holds type, mode and distance information. Also see the MatchHead table .

MatchHead Photo When photometric objects from different runs are matched (see the Match table), they form a cluster named by the minimum objID in the cluster. MatchHead has summary information (mean position, number in cluster) about each of these clusters, keyed by the objID.

Neighbors Photo This table contains ALL pairs of photometric objects within 0.5 arcminutes, regardless of their status (primary, secondary, family, outside). This table is very useful for finding objects near each other but care must be taken to select only those objects with the appropriate status.

ObjMask Photo This table contains the outlines of each detected photometric object over a 4x4 pixel grid, and the bounding rectangle of the object within the frame.frame This table should not be confused with the similarly named Mask table, which describes regions excluded from the object catalogs.

ObjType Meta This view contains the ObjType enumerated values from DataConstants as integers.

PhotoFamily Photo This view contains objects which are in PhotoObjAll, but neither PhotoPrimary nor PhotoSecondary. These objects are generated if they are neither primary nor secondary survey objects but a composite object that has been deblended or the part of an object that has been deblended wrongfully (like the spiral arms of a galaxy). These objects are kept to track how the deblender is working.

PhotoFlags Meta This view contains the PhotoFlags flag values from DataConstants as binary(8).

PhotoMode Meta This view contains the PhotoMode enumerated values from DataConstants as integers.

PhotoObj Photo This view contains objects which are in PhotoObjAll, which are either PhotoPrimary nor PhotoSecondary. These objects are generated if they are either primary nor secondary survey objects.

PhotoObjAll Photo This table contains all measure parameters for all photometric objects. Because this table is huge, a variety of Views have been created:

PhotoPrimary: all photo objects that are primary (the best version of the object)

Star: Primary objects that are classified as stars.

Galaxy: Primary objects that are classified as galaxies.

Sky: Primary objects which are sky samples.

Unknown: Primary objects which are none of the above

PhotoSecondary: all photo objects that are secondary (secondary detections).
PhotoFamily:: all photo objects which are neither primary nor secondary. These are the parents of deblended objects.

PhotoPrimary Photo This view contains objects from PhotoObjAll which are primary. As such, this view is itself a view of PhotoObj.

PhotoProfile Photo This table contains the radial profiles for each photometric object, as the mean flux in each annulus. The radii of the annuli are given in the ProfileDefs table.

PhotoSecondary Photo This view contains objects from PhotoObjAll which are secondary. As such, this view is itself a view of PhotoObj.

PhotoStatus Meta This view contains the PhotoStatus flag values from DataConstants as binary(4).

PhotoTag Photo This table contains a subset of the parameters for all of the photometric objects. It has all of the objects that are in the PhotoObjAll table, but only the most popular parameters for each.

PhotoType Meta This view contains the PhotoMode enumerated values from DataConstants as integers.

PlateX Spectro This table contains overview data for each plate used for spectroscopic observations.

PrimTarget Meta This view contains the PrimTarget flag values from DataConstants as binary(4).

ProfileDefs Photo This table provides the definitions of the radii used in computing the radial profiles for photometric objects, which are stored in the PhotoProfile table.

ProgramType Meta This view contains the ProgramType enumerated values from DataConstants as integers.

PspStatus Meta This view contains the PspStatus enumerated values from DataConstants as integers.

RC3 RC3 This table contains objects from the RC3 catalog. The objid is just a unique number for the RC3 object in the table (not a match to SDSS photoobj objid).

Region Geometry This table stores the descriptions of regions which describe various boundaries in the survey. These are represented by equations of 3D planes, intersecting the unit sphere, describing great and small circles, respectively.

Rmatrix Geometry Contains various rotation matrices between spherical coordinate systems.

Rosat External This table contains objects from the publicly available ROSAT catalogs which match an SDSS object inside the data release boundary. The matching radius used is 60 arcseconds.

RunQA Photo The RunQA table provides information relevant to the average data quality for the objects in each field. This table may be joined to the rest of your query to sub-select only fields of the very highest quality, for instance, with seeing below a certain threshold, if that is desired. If you want just one number that describes the overall quality of a field, your best bet is the fieldQall number (0=bad, 1=acceptable, 2=good, 3=excellent). This overall quality determination is based on the (dereddened) principal colors of all the stars in the field vs. the Galactic value of this quantity, the PSF quality, the difference between Aperture and PSF magnitudes for the same stars in the field, and the seeing.

RunShift Geometry In early runs the telescope was sometimes not tracking correctly. The boundaries of some of the runs had thus to be shifted by a small amount, determined by hand. This table contains these manual corrections. These should be applied to the nu values derived for these runs. Only those runs for which such a correction needs to be applied are in this table.

SDSSConstants Meta This table contains most relevant survey constants and their physical units. DO NOT confuse this with the table DataConstants, which contains most of the bit-flags and enumerated quantities relevant to the SDSS.

SecTarget Meta This view contains the SecTarget flag values from DataConstants as binary(4).

Sector Geometry This table stores the information about set of unique tile overlaps, produced as part of the tiling algorithm.

Sector2Tile Geometry This table matches tiles to sectors, and vice versa. It is table is designed to be queried in either direction - one can get all the tiles associated with a sector, or one can find all the sectors to which a tile belongs.

Segment Geometry This table contains the basic parameters associated with a Segment

Sky Photo This view contains only those primary photometric objects which are sky samples used for background measurement. As such, it is a view of PhotoPrimary, which is itself a view of PhotoObjAll.

SpecClass Meta This view contains the SpecClass enumerated values from DataConstants as integers.

SpecLine Spectro This view contains all actually measured spectroscopic lines from SpecLineAll. The view excludes those SpecLineAll objects which have category=1, and thus have not been measured. This is the view you should use to access the SpecLine data.

SpecLineAll Spectro This table contains the measured parameters for every detected spectral line in every spectroscopic object.

SpecLineIndex Spectro This table contains pre-computed spectral line indices. These are combinations of spectral line intensities used to determine various properties of galaxies, like age or metallicity.

SpecLineNames Meta This view contains the SpecLineNames enumerated values from DataConstants as integers.

SpecObj Spectro This view includes only those objects from SpecObjAll that have clean spectra. The view excludes QA and Sky and duplicates. Use this as the main way to access the spectroscopic objects.

SpecObjAll Spectro This table contains ALL the spectroscopic information for all spectroscopic objects, including a lot of duplicate and bad data. Most users will want to use the SpecObj view, which contains only objects we denote sciencePrimary.

SpecPhoto Spectro A view of joined Spectro and Photo objects that have clean spectra and photometry. The view includes only those pairs where the SpecObjSpecObj is a sciencePrimaryscienceprimary, and the BESTbest PhotoObjPhotoObj is a PRIMARYprimary. (mode=1).

SpecPhotoAll Spectro This is a pre-computed join between the PhotoObjAll and SpecObjAll tables. The photo attributes included are similar to those in PhotoTag. The table also includes certain attributes from Tiles. Many users will want to query the SpecPhoto view, which contains only those objects which are spectroscopically sciencePrimary and photometrically Primary.

SpecZStatus Meta This view contains the SpecZStatus enumerated values from DataConstants as integers.

SpecZWarning Meta This view contains the SpecZWarning flag values from DataConstants as binary(4).

Star Photo This view contains only those primary photometric objects classified as stars. As such, it is a view of PhotoPrimary, which is itself a view of PhotoObjAll.

Stetson Stetson This table contains objects from the Stetson dataset. The objid column contains matches to SDSS photoobj objids as applicable (the value is NULL if no SDSS match is found).

StripeDefs Geometry This table gives the definitions of the stripes in the survey layout as originally planned. The lower and upper limits of the actual observed stripes may differ from these values. The actual numbers are found in the Segment and Chunk tables.

Target Spectro This table keeps keeps track of objects chosen by target selection, and which therefore will be fed to the tiling algorithm. Objects are added whenever target selection is run on a new chunk. Objects are also added when southern target selection is run. In the case where an object (meaning run,rerun,camcol,field,id) is targeted more than once, there will be only one row in Target for that object, but there will be multiple entries for that Target in the TargetInfo table.

TargetInfo Spectro This table contains unique information for an object every time it is targeted. If an object is targeted more than once, there will be multiple entries for that Target in this table.

TargetParam Spectro This table contains the parameters used for a version of the target selection code.

Tile Geometry This view of TileAll excludes those Tiles that have been untiled. Thus, it contains those tiles useful for determining spectroscopic survey completeness and geometry.

TileAll Spectro This table contains information about an individual tile on the sky. Every tile ever created is in this table. The view Tile contains only the main science tiles for the northern survey.

TiledTarget Spectro This view of TiledTargetAll excludes those targets that are on tiles which have been untiled.

TiledTargetAll Spectro This table Keeps track of why a Target was assigned to a Tile. This table is designed to be searched both ways - one can find the Targets assigned to a Tile or one can find all the Tiles a Target has been assigned to (objects can be assigned to more than one tile if they are QA objects). Information comes from plPlugMapP files, but only OBJECT hole info is stored. HoleObj can be used to find other holetypes that made it to a Plate.

TilingBoundary Geometry A view of TilingGeometry objects that have isMask = 0 The view excludes those TilingGeometry objects that have isMask = 1. See also TilingMask.

TilingGeometry Spectro This table contains geometric information about TilingRegions, including both tiling boundary and generic information.

TilingInfo Spectro Contain info on what happened to a TargetObj in a run of tilingtiling software.

TilingMask Geometry A view of TilingGeometry objects that have isMask = 1 The view excludes those TilingGeometry objects that have isMask = 0. See also TilingBoundary.

TilingNote Spectro Contains human readable notes for a run of tiling. This includes information on why specific tiles may be empty or problems with a given tile.

TilingRun Spectro Contains basic information for a run of tiling.

TiMask Meta This view contains the TiMask flag values from DataConstants as binary(4).

Unknown Photo This view contains only those primary photometric objects classified as unknown (not a star,galaxy,or sky). As such, it is a view of PhotoPrimary, which is itself a view of PhotoObjAll.

USNO External This table contains all of the objects in the USNO-B catalog which match an SDSS object inside the data release boundary. However, because this matching was originally done with USNO-A, many new fields from the newer USNO-N are NOT in this table (such as the POSS-II matches).

XCRedshift Spectro This table contains the cross-correlation redshifts for all spectroscopic objects.

Zone Geometry This table is mostly for internal database mechanics. In order to speed up all-sky cross-correlations, this table organizes the PhotoObjs into 0.5 arcmin declination zones, indexed by the zone number and ra.

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name	type	text
Best2Sector	Geometry	This table places the Best photometric objects into sectors, which are used to divide the sky into geometric regions. Each object appears once, and only once, in this table because a given ra and dec belong to a unique sector.
Chunk	Geometry	This table contains some very basic information for each chunk loaded in the database.
Convex	Geometry
CoordType	Meta	This view contains the CoordType enumerated values from DataConstants as integers.
DataConstants	Meta	The table DataConstants contains most of the bit-flags and enumerated quantities relevant to the SDSS. DO NOT confuse this with SDSSConstants, which contains actual constants used in data processing.
DBColumns	Meta	This table contains an extremely brief description of every column in every table in the database. Because some quantities appear in multiple tables with multiple meanings, a quantity is uniquely defined only within a single table.
DBObjectDescription	Meta	This table contains the long descriptions for every table and view in the database.
DBObjects	Meta	This table contains names and descriptions of all the tables and views in the database.
DBViewCols	Meta	This table stores the names and descriptions of all columns in all views in the database. This is used by the auto-documentation.
ELRedShift	Spectro	This table contains ALL of the measured emission lines, along with their redshifts and related information, for ALL spectroscopic objects.
Field	Meta	This table contains all the measured parameters of each imaging field, along with relevant summary statistics, and astrometric and photometric information.
FieldMask	Meta	This view contains the FieldMask flag values from DataConstants as binary(4).
FieldProfile	Photo	Need description.
FieldQuality	Meta	This view contains the FieldQuality enumerated values from DataConstants as integers.
First	External	This table stores measurements from the FIRST radio survey for those FIRST objects which are matched to SDSS photometric objects. ????
Frame	Photo	This table actually contains false color JPEG images of the fields, and their most relevant parameters, in particular the coefficients of the astrometric transformation, and position info. The images are stored at several zoom levels.
FramesStatus	Meta	This view contains the FramesStatus enumerated values from DataConstants as integers.
Galaxy	Photo	This view contains only those primary photometric objects classified as galaxies. As such, it is a view of PhotoPrimary, which is itself a view of PhotoObjAll.
HoleObj	Spectro	This table stores information for non-OBJECT holes on spectroscopic plates, and for OBJECT holes that were not mapped by the fiber mapper.
HoleType	Meta	This view contains the HoleType enumerated values from DataConstants as integers.
ImageMask	Meta	This view contains the ImageMask flag values from DataConstants as binary(2).
InsideMask	Meta	This view contains the InsideMask flag values from DataConstants as binary(1).
Mask	Geometry	This table contains information about each photometric mask.
MaskedObject	Geometry	This is a list of all masked photometric objects. These objects were detected but are within the boundaries of a masked area (see the Mask table) and thus unreliable. Each object may appear multiple times, if it is masked for multiple reasons.
MaskType	Meta	This view contains the MaskType enumerated values from DataConstants as integers.
Match	Photo	This table contains pairs of photometric objects from different runs (times) that probably are the same object. These must be SDSS primary or secondary objects, of type STAR, GALAXY, and UNKNOWN, within 1 arcsec of one another, and from different runs. The table also holds type, mode and distance information. Also see the MatchHead table .
MatchHead	Photo	When photometric objects from different runs are matched (see the Match table), they form a cluster named by the minimum objID in the cluster. MatchHead has summary information (mean position, number in cluster) about each of these clusters, keyed by the objID.
Neighbors	Photo	This table contains ALL pairs of photometric objects within 0.5 arcminutes, regardless of their status (primary, secondary, family, outside). This table is very useful for finding objects near each other but care must be taken to select only those objects with the appropriate status.
ObjMask	Photo	This table contains the outlines of each detected photometric object over a 4x4 pixel grid, and the bounding rectangle of the object within the frame.frame This table should not be confused with the similarly named Mask table, which describes regions excluded from the object catalogs.
ObjType	Meta	This view contains the ObjType enumerated values from DataConstants as integers.
PhotoFamily	Photo	This view contains objects which are in PhotoObjAll, but neither PhotoPrimary nor PhotoSecondary. These objects are generated if they are neither primary nor secondary survey objects but a composite object that has been deblended or the part of an object that has been deblended wrongfully (like the spiral arms of a galaxy). These objects are kept to track how the deblender is working.
PhotoFlags	Meta	This view contains the PhotoFlags flag values from DataConstants as binary(8).
PhotoMode	Meta	This view contains the PhotoMode enumerated values from DataConstants as integers.
PhotoObj	Photo	This view contains objects which are in PhotoObjAll, which are either PhotoPrimary nor PhotoSecondary. These objects are generated if they are either primary nor secondary survey objects.
PhotoObjAll	Photo	This table contains all measure parameters for all photometric objects. Because this table is huge, a variety of Views have been created: PhotoPrimary: all photo objects that are primary (the best version of the object) Star: Primary objects that are classified as stars. Galaxy: Primary objects that are classified as galaxies. Sky: Primary objects which are sky samples. Unknown: Primary objects which are none of the above PhotoSecondary: all photo objects that are secondary (secondary detections). PhotoFamily:: all photo objects which are neither primary nor secondary. These are the parents of deblended objects.
PhotoPrimary	Photo	This view contains objects from PhotoObjAll which are primary. As such, this view is itself a view of PhotoObj.
PhotoProfile	Photo	This table contains the radial profiles for each photometric object, as the mean flux in each annulus. The radii of the annuli are given in the ProfileDefs table.
PhotoSecondary	Photo	This view contains objects from PhotoObjAll which are secondary. As such, this view is itself a view of PhotoObj.
PhotoStatus	Meta	This view contains the PhotoStatus flag values from DataConstants as binary(4).
PhotoTag	Photo	This table contains a subset of the parameters for all of the photometric objects. It has all of the objects that are in the PhotoObjAll table, but only the most popular parameters for each.
PhotoType	Meta	This view contains the PhotoMode enumerated values from DataConstants as integers.
PlateX	Spectro	This table contains overview data for each plate used for spectroscopic observations.
PrimTarget	Meta	This view contains the PrimTarget flag values from DataConstants as binary(4).
ProfileDefs	Photo	This table provides the definitions of the radii used in computing the radial profiles for photometric objects, which are stored in the PhotoProfile table.
ProgramType	Meta	This view contains the ProgramType enumerated values from DataConstants as integers.
PspStatus	Meta	This view contains the PspStatus enumerated values from DataConstants as integers.
RC3	RC3	This table contains objects from the RC3 catalog. The objid is just a unique number for the RC3 object in the table (not a match to SDSS photoobj objid).
Region	Geometry	This table stores the descriptions of regions which describe various boundaries in the survey. These are represented by equations of 3D planes, intersecting the unit sphere, describing great and small circles, respectively.
Rmatrix	Geometry	Contains various rotation matrices between spherical coordinate systems.
Rosat	External	This table contains objects from the publicly available ROSAT catalogs which match an SDSS object inside the data release boundary. The matching radius used is 60 arcseconds.
RunQA	Photo	The RunQA table provides information relevant to the average data quality for the objects in each field. This table may be joined to the rest of your query to sub-select only fields of the very highest quality, for instance, with seeing below a certain threshold, if that is desired. If you want just one number that describes the overall quality of a field, your best bet is the fieldQall number (0=bad, 1=acceptable, 2=good, 3=excellent). This overall quality determination is based on the (dereddened) principal colors of all the stars in the field vs. the Galactic value of this quantity, the PSF quality, the difference between Aperture and PSF magnitudes for the same stars in the field, and the seeing.
RunShift	Geometry	In early runs the telescope was sometimes not tracking correctly. The boundaries of some of the runs had thus to be shifted by a small amount, determined by hand. This table contains these manual corrections. These should be applied to the nu values derived for these runs. Only those runs for which such a correction needs to be applied are in this table.
SDSSConstants	Meta	This table contains most relevant survey constants and their physical units. DO NOT confuse this with the table DataConstants, which contains most of the bit-flags and enumerated quantities relevant to the SDSS.
SecTarget	Meta	This view contains the SecTarget flag values from DataConstants as binary(4).
Sector	Geometry	This table stores the information about set of unique tile overlaps, produced as part of the tiling algorithm.
Sector2Tile	Geometry	This table matches tiles to sectors, and vice versa. It is table is designed to be queried in either direction - one can get all the tiles associated with a sector, or one can find all the sectors to which a tile belongs.
Segment	Geometry	This table contains the basic parameters associated with a Segment
Sky	Photo	This view contains only those primary photometric objects which are sky samples used for background measurement. As such, it is a view of PhotoPrimary, which is itself a view of PhotoObjAll.
SpecClass	Meta	This view contains the SpecClass enumerated values from DataConstants as integers.
SpecLine	Spectro	This view contains all actually measured spectroscopic lines from SpecLineAll. The view excludes those SpecLineAll objects which have category=1, and thus have not been measured. This is the view you should use to access the SpecLine data.
SpecLineAll	Spectro	This table contains the measured parameters for every detected spectral line in every spectroscopic object.
SpecLineIndex	Spectro	This table contains pre-computed spectral line indices. These are combinations of spectral line intensities used to determine various properties of galaxies, like age or metallicity.
SpecLineNames	Meta	This view contains the SpecLineNames enumerated values from DataConstants as integers.
SpecObj	Spectro	This view includes only those objects from SpecObjAll that have clean spectra. The view excludes QA and Sky and duplicates. Use this as the main way to access the spectroscopic objects.
SpecObjAll	Spectro	This table contains ALL the spectroscopic information for all spectroscopic objects, including a lot of duplicate and bad data. Most users will want to use the SpecObj view, which contains only objects we denote sciencePrimary.
SpecPhoto	Spectro	A view of joined Spectro and Photo objects that have clean spectra and photometry. The view includes only those pairs where the SpecObjSpecObj is a sciencePrimaryscienceprimary, and the BESTbest PhotoObjPhotoObj is a PRIMARYprimary. (mode=1).
SpecPhotoAll	Spectro	This is a pre-computed join between the PhotoObjAll and SpecObjAll tables. The photo attributes included are similar to those in PhotoTag. The table also includes certain attributes from Tiles. Many users will want to query the SpecPhoto view, which contains only those objects which are spectroscopically sciencePrimary and photometrically Primary.
SpecZStatus	Meta	This view contains the SpecZStatus enumerated values from DataConstants as integers.
SpecZWarning	Meta	This view contains the SpecZWarning flag values from DataConstants as binary(4).
Star	Photo	This view contains only those primary photometric objects classified as stars. As such, it is a view of PhotoPrimary, which is itself a view of PhotoObjAll.
Stetson	Stetson	This table contains objects from the Stetson dataset. The objid column contains matches to SDSS photoobj objids as applicable (the value is NULL if no SDSS match is found).
StripeDefs	Geometry	This table gives the definitions of the stripes in the survey layout as originally planned. The lower and upper limits of the actual observed stripes may differ from these values. The actual numbers are found in the Segment and Chunk tables.
Target	Spectro	This table keeps keeps track of objects chosen by target selection, and which therefore will be fed to the tiling algorithm. Objects are added whenever target selection is run on a new chunk. Objects are also added when southern target selection is run. In the case where an object (meaning run,rerun,camcol,field,id) is targeted more than once, there will be only one row in Target for that object, but there will be multiple entries for that Target in the TargetInfo table.
TargetInfo	Spectro	This table contains unique information for an object every time it is targeted. If an object is targeted more than once, there will be multiple entries for that Target in this table.
TargetParam	Spectro	This table contains the parameters used for a version of the target selection code.
Tile	Geometry	This view of TileAll excludes those Tiles that have been untiled. Thus, it contains those tiles useful for determining spectroscopic survey completeness and geometry.
TileAll	Spectro	This table contains information about an individual tile on the sky. Every tile ever created is in this table. The view Tile contains only the main science tiles for the northern survey.
TiledTarget	Spectro	This view of TiledTargetAll excludes those targets that are on tiles which have been untiled.
TiledTargetAll	Spectro	This table Keeps track of why a Target was assigned to a Tile. This table is designed to be searched both ways - one can find the Targets assigned to a Tile or one can find all the Tiles a Target has been assigned to (objects can be assigned to more than one tile if they are QA objects). Information comes from plPlugMapP files, but only OBJECT hole info is stored. HoleObj can be used to find other holetypes that made it to a Plate.
TilingBoundary	Geometry	A view of TilingGeometry objects that have isMask = 0 The view excludes those TilingGeometry objects that have isMask = 1. See also TilingMask.
TilingGeometry	Spectro	This table contains geometric information about TilingRegions, including both tiling boundary and generic information.
TilingInfo	Spectro	Contain info on what happened to a TargetObj in a run of tilingtiling software.
TilingMask	Geometry	A view of TilingGeometry objects that have isMask = 1 The view excludes those TilingGeometry objects that have isMask = 0. See also TilingBoundary.
TilingNote	Spectro	Contains human readable notes for a run of tiling. This includes information on why specific tiles may be empty or problems with a given tile.
TilingRun	Spectro	Contains basic information for a run of tiling.
TiMask	Meta	This view contains the TiMask flag values from DataConstants as binary(4).
Unknown	Photo	This view contains only those primary photometric objects classified as unknown (not a star,galaxy,or sky). As such, it is a view of PhotoPrimary, which is itself a view of PhotoObjAll.
USNO	External	This table contains all of the objects in the USNO-B catalog which match an SDSS object inside the data release boundary. However, because this matching was originally done with USNO-A, many new fields from the newer USNO-N are NOT in this table (such as the POSS-II matches).
XCRedshift	Spectro	This table contains the cross-correlation redshifts for all spectroscopic objects.
Zone	Geometry	This table is mostly for internal database mechanics. In order to speed up all-sky cross-correlations, this table organizes the PhotoObjs into 0.5 arcmin declination zones, indexed by the zone number and ra.