用 GCC 讓你的 PostgreSQL 噴噴噴～

GCC PostgreSQL
Applying Compiler Optimizations in PostgreSQL

PostgreSQL
•
• Open source ( source code)
• PostgreSQL License (BSD-like License)
•

GCC (GNU Compiler Collection)
• Compiler system
• C
•

Compiler
Compiler
machine
code
source
code

Compiler
• Google Google
•
•
•
source code
.
.
.
Compiler.c
.c
.c
.o
.o
.o
Compiler
Compiler
Linker
object file
executable

Function Call Inline ( )
•
Paul SayHello
SayHello

inline
• inline Alice Mary Paul
)
cache cache miss
• v.s.
NO!!!

• CPU bound v.s. IO bound
• PostgreSQL

PostgreSQL Compiler
• PostgreSQL
• -O0
• -O3
• -O3 -O0 1.5
• PostgreSQL
• PostgreSQL
0
0.5
1
1.5
2
CentOS Ubuntu
Compiler Sensitive
O0 O3

baseline (default)
• function
function
• function call overhead

Benchmark
• pgbench, select-only mode
• P C
• 13MB
• IO
CPU Intel® Core™ i7-6700
Memory 16GB
OS CentOS 7.3
Compiler GCC 5.4.0
PostgreSQL 9.6.2

(12% improvement)
0.9
0.95
1
1.05
1.1
1.15
baseline O2 O3 O2 flto O2 finline-functions O2 flto finline-
functions
CentOS
CentOS
1.12
1.03 1.04

• -finline-functions
• functions inline
• function
• -flto (linking time optimization)
• object file
• object file
• object file function inline

-O2 –finline-functions –flto
• function
function inline
• function call overhead

Conclusion
•
•
•
• PostgreSQL 12%

Thank you
Contact: tclin914@gmail.com

Q & A
• inline function
• inline function inline
inline improment

Problem
• 資料庫管理系統遇到執行效能上的瓶頸
• 希望能從編譯器方面來優化PostgreSQL

Method
• 使用 GCC 許多的不同優化組合，並藉由 benchmark 的執行測量，
去找出最佳的優化組合

Solution
• 使用 GCC 特定的優化組合來優化 PostgreSQL
• 藉由分析得知其效果是來自哪些因素

Outline
• Compiler optimizations
• How to find optimization options to speed up PostgreSQL
• Experimental and profiling result
• Conclusion

inline
• inline function inline
• inline Alice Mary Paul
)
cache cache miss
•
NO!!!
Paul do_something
do_something
do_something …

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