<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>Hi bborie,</div><div><br></div><div>Thanks for the idea. I've set up the logging and checked and only one query is being sent by the client. I've also checked the code used by the client, which simply runs one query and gets the results.</div><div><br></div><div>Does anyone have any idea why this may be happening?</div><div><br></div><div><div>Cheers,</div><div><br></div><div>Robin</div></div><div><br></div><div>------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------</div><div><br></div><div>Robin,<br><br>I can't say for certain but it looks like your client (not psql) is<br>sending off multiple queries. The nulls would return if the point being<br>sampled isn't in any of the tiles.<br><br>You could enable statement logging (log_statement) in PostgreSQL to see<br>what statements are being run from your connector.<br><br><a href="http://www.postgresql.org/docs/9.0/interactive/runtime-config-logging.html#RUNTIME-CONFIG-LOGGING-WHAT">http://www.postgresql.org/docs/9.0/interactive/runtime-config-logging.html#RUNTIME-CONFIG-LOGGING-WHAT</a><br><br>-bborie</div></body></html>