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<font face="Helvetica, Arial, sans-serif">In a word, no. Unless the
query returns a constant value, the run time will depend on the
values of the data and on what machine it's being run on and the
easiest way to determine those things are to actually run the
query.<br>
<br>
If what you want is guidance about which queries are going to need
optimization, the cost output from the EXPLAIN command will
probably tell you where to spend your time. The cost output will
also tell you whether you have succeeded in improving the relative
performance of a query without actually having to run it.<br>
<br>
Ruven Brooks</font>
<div class="moz-cite-prefix">On 8/3/2020 9:56 AM, Shaozhong SHI
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CA+i5JwZW0+3ESH_O9=5M1Bg8aZD06uqkAQ+Peg-nSqYP8WxLLQ@mail.gmail.com">
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<div dir="ltr">Hi,
<div><br>
</div>
<div>I tried to use "explain" to look into the query plan. It
only gives me the cost and rows, and does not give an estimate
of time to run the query.</div>
<div><br>
</div>
<div>"Explain analyze" gives an estimate of time needed, but for
a Big Data query, one has to wait to get an answer,</div>
<div><br>
</div>
<div>Is there a way to get an estimate of time for running a
query, without actually running it.</div>
<div><br>
</div>
<div>Looking forward to hearing from you.</div>
<div><br>
</div>
<div>Regards,</div>
<div><br>
</div>
<div>Shao</div>
</div>
<br>
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