Re: BUG #17200: PostgreSQL-Support Profile Guide Optimization(Clang/GCC)?

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?

On Wed, 22 Sept 2021 at 18:48, PG Bug reporting form <noreply(at)postgresql(dot)org>
wrote:

> The following bug has been logged on the website:
>
> Bug reference: 17200
> Logged by: hpc researcher
> Email address: hpcresearch(dot)mspk(at)gmail(dot)com
> PostgreSQL version: 13.3
> Operating system: RHEL8.4
> Description:
>
> 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)
>
> Ref:
> https://clang.llvm.org/docs/UsersManual.html#profiling-with-instrumentation
>
>