Error Messages

<div class="WordSection1"><p class="MsoNormal">When I run commands other than SELECT, I get error messages like this
fromExplain<p class="MsoNormal"> <p class="MsoNormal">ALTER TABLE sites ALTER COLUMN meters_wgs84 SET NOT NULL;<p
class="MsoNormal">Queryresult with 0 rows will be returned.<p class="MsoNormal"> <p class="MsoNormal">ERROR:  syntax
errorat or near "ALTER"<p class="MsoNormal">LINE 1: ... (ANALYZE off, VERBOSE off, COSTS on, BUFFERS off)ALTER
TABL...<pclass="MsoNormal">                                                        ^<p class="MsoNormal"> <p
class="MsoNormal">**********Error **********<p class="MsoNormal"> <p class="MsoNormal">ERROR: syntax error at or near
"ALTER"<pclass="MsoNormal">SQL state: 42601<p class="MsoNormal">Character: 58<p class="MsoNormal"> <p
class="MsoNormal">Thecommand will execute just fine. Is this normal?</div>