| PhotoObj pairs from different runs (times) that probably are the same object. |
| SDSS primary and secondary objects of type STAR, GALAXY, and UNKNOWN within 1 arcsec of one another and from different runs (so two different observations) Table also holds type, mode and distance information. See also MatchHead Table. |
| Index Type | Key or Field List |
| primary key | objID, matchObjID |
| foreign key | PhotoObjAll(objID) |