Bug 4023

Summary: TOP N queries in merge tables
Product: SQL Reporter: Stefan de Konink <stefan>
Component: allAssignee: SQL devs <bugs-sql>
Status: NEW ---    
Severity: enhancement    
Priority: Normal    
Version: 11.21.19 (Jul2015-SP4)   
Hardware: x86_64 (amd64/em64t)   
OS: Linux   

Description Stefan de Konink 2016-06-13 13:44:12 CEST
User-Agent:       Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/49.0.2623.108 Chrome/49.0.2623.108 Safari/537.36
Build Identifier: 

Currently a top N query by select * from mergetable limit 1; materializes the entire tableset. Would be nice if it would select breadth-first.

Reproducible: Always

MonetDB 5 server v11.24.0 (64-bit, 64-bit oids, 128-bit integers)
This is an unreleased version
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Found 62.8GiB available memory, 8 available cpu cores
  libpcre: 8.38 2015-11-23 (compiled with 8.38)
  openssl: OpenSSL 1.0.2h  3 May 2016 (compiled with OpenSSL 1.0.2h  3 May 2016)
  libxml2: 2.9.4 (compiled with 2.9.4)
Compiled by: skinkie@chamechaude (x86_64-pc-linux-gnu)
Compilation: gcc -O3  -pipe    -Werror -Wall -Wextra -W -Werror-implicit-function-declaration -Wpointer-arith -Wdeclaration-after-statement -Wundef -Wformat=2 -Wno-format-nonliteral -Winit-self -Winvalid-pch -Wmissing-declarations -Wmissing-format-attribute -Wmissing-prototypes -Wold-style-definition -Wpacked -Wunknown-pragmas -Wvariadic-macros -fstack-protector-all -Wstack-protector -Wpacked-bitfield-compat -Wsync-nand -Wjump-misses-init -Wmissing-include-dirs -Wlogical-op -Wunreachable-code
Linking    : /usr/x86_64-pc-linux-gnu/bin/ld -m elf_x86_64