Thread: Counting Row
<div class="Section1"><p class="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt;
font-family:Arial">Hi postgre people. Can anybody help to fix performance of my query?</span></font><p
class="MsoNormal"><fontface="Arial" size="2"><span style="font-size:10.0pt;
font-family:Arial"> </span></font><p class="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt;
font-family:Arial">Let say, I have <b><span style="font-weight:bold">n</span></b> number of queue ticket. (Which I use
SELECT).</span></font><pclass="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt;
font-family:Arial">Is there faster method to know where is my ticket number in queue?</span></font><p
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font-family:Arial"> </span></font><p class="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt;
font-family:Arial">I use (while in PHP script ) and count one by one until my ticket number match with row field
.</span></font><pclass="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt;
font-family:Arial"> </span></font><p class="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt;
font-family:Arial">$sql="select * from [MYTABLE] where [CONDITION] order by [FIELDORDER];</span></font><p
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font-family:Arial">$rs=&$ctclink->Execute($sql);</span></font><p class="MsoNormal"><font face="Arial"
size="2"><spanstyle="font-size:10.0pt;
font-family:Arial">$ctr=1;</span></font><p class="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt;
font-family:Arial">$pos=0;</span></font><p class="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt;
font-family:Arial"> </span></font><p class="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt;
font-family:Arial"> while (!$rs->EOF) {</span></font><p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size:10.0pt;
font-family:Arial"> if ($rs->fields[0]==$recid) {</span></font><p class="MsoNormal"><font face="Arial"
size="2"><spanstyle="font-size:10.0pt;
font-family:Arial"> $pos=$ctr;</span></font><p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size:10.0pt;
font-family:Arial"> break;</span></font><p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size:10.0pt;
font-family:Arial"> } else {</span></font><p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size:10.0pt;
font-family:Arial"> $ctr++;</span></font><p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size:10.0pt;
font-family:Arial"> $rs->MoveNext(); }</span></font><p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size:10.0pt;
font-family:Arial"> }</span></font><p class="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt;
font-family:Arial"> </span></font><p class="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt;
font-family:Arial"> print $pos</span></font><p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size:10.0pt;
font-family:Arial"> </span></font><p class="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt;
font-family:Arial"> </span></font><p class="MsoNormal"><font face="Arial" size="2"><span style="font-size:10.0pt;
font-family:Arial">is there any method to do that with simple??</span></font><p class="MsoNormal"><font face="Arial"
size="2"><spanstyle="font-size:10.0pt;
font-family:Arial"> </span></font><p class="MsoNormal"><b><font face="Broadway BT" size="3"><span style="font-size:
12.0pt;font-family:"Broadway BT";font-weight:bold">Thanks,</span></font></b><p class="MsoNormal"><font face="Times New
Roman"size="3"><span style="font-size:
12.0pt"> </span></font></div>
I'd suggest : - first getting the 'order fields' value for the ticket you want : SELECT field_order FROM mytable WHERE condition AND identifier=the_one_you're_looking_for ORDER BY field_order DESC LIMIT 1 - then counting all the tickets up to this order : SELECT count(*) FROM mytable WHERE condition AND field_order <= (SELECT field_order FROM mytable WHERE condition AND identifier=the_one_you're_looking_for ORDER BY field_order DESC LIMIT 1) You could also use a plpgsql function to reimplement your PHP thing, which should be faster than doing it in PHP, but probably slower than the example above. # But there is a simpler solution. How do you model the position of a ticket in the queue ? What is the 'order field' you mention ? If your table has a SERIAL PRIMARY KEY, it's monotonous, so you can use this without further worries. table tickets_queues (id SERIAL PRIMARY KEY, queue_id, ticket_id, UNIQUE( queue_id, ticket_id) ) to get the position of a ticket (by its ticket_id) in a queue : SELECT count(*) FROM tickets_queue WHERE queue_id=# AND id <= (SELECT id FROM tickets_queue WHERE ticket_id=# AND queue_id=#)