Hi, Right now I am evaluating MonetDB and try to analyze a dataset that consists of 10 million rows. The data set has 2 tables, table a stores 10 million rows, table b stores 1 million rows. Both tables are being joined and some statistical values are being calculated (QUARTILE, AVG, SUM and GROUP BY). MonetDB is promising fast here. When starting up the database and executing the query the result is being returned within 4 seconds. I tried to execute the same SQL query 1000 times sequentially and to my surprise after the 60th iteration monetDB crashed because of insuffcient disk space. As far as I read intermediate results are being materialized within the bat folder. The .tail files are not being removed after a query was executed successfully and the files are not even removed after the database conenction is being closed. When I restart the server (dbfarm) the files are cleaned up perfectly. I am just wondering if this default behaviour can be changed? Are there any ways to enforce cleaning up the files? How to avoid a server crash because of insufficient memory? For the system I am planning to use monetDB for I am not able to restart the server before I execute the SQL queries. Thank you very much, Alex