Tried PostgreSQL with GCC-Profile guided optimization(PGO) and it is working with the HammerDB benchmark environment. Similarly, we tried PostgreSQL with Clang(12.0V) -Profile guided optimization(PGO) and it is not working and observed an error "warning: default.profraw: Failed to uncompress data (zlib) error: No profiles could be merged"
Reference bug #: 17200
Are there any plans to fix this issue in upcoming releases? Otherwise, could you please provide us a workaround/patch for this issue?
I followed the below steps on Profile Guide Optimization with Clang Environment. And benchmark environment used HammedDB.
1.Build command: ------------ $ CC=clang CXX=clang++ ../configure --prefix=<path-to-install> CFLAGS='-O3 -fprofile-instr-generate' CXXFLAGS='-O3 -std=c++14 -stdlib=libc++ -fprofile-instr-generate' 2.Run HammerDB client(tpcc-schmea + test run(vu's). 3. default.profraw created in PostgreSQL(<path-to-install>) 4. convert the “raw” profile format by clang.(the merge command:llvm-profdata tool) 5. llvm-profdata merge -output=code.profdata code- default.profraw warning: default.profraw: Failed to uncompress data (zlib) error: No profiles could be merged.(step5)
