Hi, Martin Yes, before performance analysis, load is zero, the server is Linix console only. My RAM memory is low for this database size. what do you think ? Att, Hi, about slow query Yes, there is, but still left over resources. While the query (which takes 90 minutes) are running, to perform another in another table (9M rows), this latter returns usually in seconds. Hi Its all about concurrent processes while working with MonetDB. All those processes compete for RAM and disk bandwidth. Even running a browser already takes off a few GB from your RAM. At some point, you end up swapping intermediates to disk, which is a slow process (depending on your HDD). For performance analysis, you better shut down all the processes you don't need. Ideally, the CPU load = 0 before doing a performance analysis.

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A simple "select count(*) from table", run on 90 minutes.

that is not normal. most likely there are a lot of other processes competing for resources.

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Luciano Sasso Vieira Data Scientist & Solutions Architect luciano@gsgroup.com.br http://www.gsgroup.com.br | tel: 17 3353-0833 | cel: 17 99706-9335 www.gsgroup.com.br http://www.gsgroup.com.br --- Este email foi escaneado pelo Avast antivírus. https://www.avast.com/antivirus