Hi, We have an application (http://tmt.gtri.gatech.edu/lytic.html) based on a relatively modest, single (~1-10M row, ~20 column) MonetDB table (Win7, 64 bit, Jan14-SP1 server release, quad-core, 8GB RAM) and have been encountering sporadic SELECT query failures with the error: "Insufficient space for HEAP of 1017856 bytes". Since I've been trying in earnest to diagnose this, that byte value has been consistent, FWIW. The failures are frustratingly intermittent; if I rerun a failing query (by hand, using mclient) it sometimes fails again, and sometimes works correctly. I've been unable to figure out any sort of pattern. Unfortunately, I can't post the exact table and query, but the general form of the queries (which have ~5-10 case clauses) are: SELECT CASE WHEN Foo = 'ValueA' and Bar LIKE 'ValueB%' THEN 100*(Baz-1234)/1234 WHEN Foo = 'ValueC' and Bar LIKE 'ValueD%' THEN 100*(Baz-3456)/3456 ... END FROM table WHERE <same case statement as above> IS NOT NULL LIMIT 1 Any ideas what I might do to narrow this down or other information I might provide? I captured an explain of a failing query--it's many hundreds (1000s?) of lines, so I didn't want to include it here in full. All suggestions appreciated. Thanks, Ed P.S. MonetDB has been a fantastic complement to our application, thanks to everyone involved!