Can you try running your server with valgrind? In other contexts, I’ve found that if the error makes no sense, memory corruption is a likely cause. Not sure how applicable that is here. From: users-list [mailto:users-list-bounces+david.b.anderson=citi.com@monetdb.org] On Behalf Of Anthony Damico Sent: Tuesday, January 31, 2017 9:34 AM To: Communication channel for MonetDB users Subject: Re: MALException:opt.remap:Function 'calc.isnil' not defined hi, i continued narrowing down my example for this issue. i attempted to reproduce it on an empty dataset and also on a different dataset, but neither triggered the error. the query is just two left joins stacked 33 times with UNION ALLs. if i remove even one of the 33 stacks (many are duplicated), the error disappears. this error did not occur on Jun2016_SP2, it appears to have been introduced with Dec2016 here is the condensed (easier to read) code that displays the core commands: https://drive.google.com/file/d/0B3LuuP081KDYMXU1SWtjbGp6Q1k/viewhttps://urldefense.proofpoint.com/v2/url?u=https-3A__drive.google.com_file_d_0B3LuuP081KDYMXU1SWtjbGp6Q1k_view&d=DQMFaQ&c=j-EkbjBYwkAB4f8ZbVn1Fw&r=8_GYjk1edsyLJlNaxMxYxBJsviF3JXYvwDK42uy5KWU&m=6uGLRZnoW0D_3SjYVX2KwcovvddKh7crcAQU178XsXk&s=ueiJFBb8fP9NAALn46K87-lnM1--xO2jShlsM2EWYsg&e= here's the PLAN: https://drive.google.com/file/d/0B3LuuP081KDYMnJ5bFh2Zi1yTUk/viewhttps://urldefense.proofpoint.com/v2/url?u=https-3A__drive.google.com_file_d_0B3LuuP081KDYMnJ5bFh2Zi1yTUk_view&d=DQMFaQ&c=j-EkbjBYwkAB4f8ZbVn1Fw&r=8_GYjk1edsyLJlNaxMxYxBJsviF3JXYvwDK42uy5KWU&m=6uGLRZnoW0D_3SjYVX2KwcovvddKh7crcAQU178XsXk&s=7EDRW8q56-pk3zaBVI4kkkhLTUsuOsUC8M6SKh1sApg&e= here's the full query: https://drive.google.com/file/d/0B3LuuP081KDYWV9kQkxzbllUTE0/viewhttps://urldefense.proofpoint.com/v2/url?u=https-3A__drive.google.com_file_d_0B3LuuP081KDYWV9kQkxzbllUTE0_view&d=DQMFaQ&c=j-EkbjBYwkAB4f8ZbVn1Fw&r=8_GYjk1edsyLJlNaxMxYxBJsviF3JXYvwDK42uy5KWU&m=6uGLRZnoW0D_3SjYVX2KwcovvddKh7crcAQU178XsXk&s=ztDIvXbVB_ZEcglyOWFGH8jom2XwUvZKmJIGDXXm1l8&e= i am confused how calc.isnil or calc.> could not be defined? they are both defined for "any" type here: https://github.com/MonetDB/MonetDB/blob/b40c1c1a33feece365fa6655802b6577df04...https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_MonetDB_MonetDB_blob_b40c1c1a33feece365fa6655802b6577df04af62_sql_common_sql-5Ftypes.c-23L1408-2DL1409&d=DQMFaQ&c=j-EkbjBYwkAB4f8ZbVn1Fw&r=8_GYjk1edsyLJlNaxMxYxBJsviF3JXYvwDK42uy5KWU&m=6uGLRZnoW0D_3SjYVX2KwcovvddKh7crcAQU178XsXk&s=r4HgMzQSTK_dP_Mi03a9SJTzDG7Bob-3rwkZGZQDkZg&e= please help? thanks all