https://community.cloudera.com/t5/Support-Questions/Urgent-Presto-Query-Error-Query-exceeded-max-memory-size-of/m-p/167419#M129751 <P>You can take a look at this post:</P><P><A href="https://community.hortonworks.com/articles/10485/introduction-to-presto.html" target="_blank">https://community.hortonworks.com/articles/10485/introduction-to-presto.html</A></P><P>Then let me answer you question:</P><P>Q1)How we can come to know what is optimum size of memory/ram allocation.</P><P style="margin-left: 20px;">A) You can get the value from presto UI.</P><P><A href="http://&lt;host-name&gt;:8080/" target="_blank">http://&lt;host-name&gt;:8080/</A></P><P>All the queries are listed here. If you click one of them, you can see details , such as peak memory usage.</P><P>Q3) Is there any way to restrict user from launching such a huge query or any other preventive approach</P><P style="margin-left: 20px;">A) Yes. <A href="https://community.hortonworks.com/articles/10485/introduction-to-presto.html">ref url<BR /></A></P><P style="margin-left: 20px;"><A href="https://community.hortonworks.com/articles/10485/introduction-to-presto.html"></A></P><P style="margin-left: 20px;">config.properties example:</P><PRE>query.max-memory=30GB query.max-memory-per-node=5GB</PRE> Tue, 16 Jan 2018 16:22:48 GMT zzeng 2018-01-16T16:22:48Z