Due to the sheer size of the SDSS databases, queries that search the entire TB database (BEST or TARG), or queries that are not formulated in the most efficient way, can take a very long time to execute (hours). To be fair to other users and prevent the CAS from bogging down, the SkyServer search tools have built-in timeouts and row limits (max. number of rows in query results). These are listed below for eachtool.

If your query is timing out, please see the Optimizing Queries section of the SQL Intro Page.

If none of these options work, we may be able to make special arrangements for you to obtain the data that you need. Please contact the helpdesk in that case.

Tool/Page	Timeout (sec)	Row Limit	Remarks
SQL Search	3600	100000	Browsers cannot render large outputs
Object Crossid	600	100000	Applies to both Upload and Speclist
Form Query	600	100000	Imaging (IQS) and Spectro (SQS)
Visual Tools	600	NA	Finding, Navigate, Image Lists
sdssQA	3600	No limit	Downloadable Java client
Default	90	100000	Defaults when none of the above limits apply