Horton

Re: JIT compiling with LLVM v11

Tom Lane <tgl@sss.pgh.pa.us>

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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andres Freund <andres@anarazel.de>
Cc: Peter Eisentraut <peter.eisentraut@2ndquadrant.com>, Pg Hackers <pgsql-hackers@postgresql.org>
Date: 2018-03-06T21:20:25Z
Lists: pgsql-hackers 
Andres Freund <andres@anarazel.de> writes:
> I'm not too worried about that scenario. If, for a cheap plan, the
> planner ends up with a seqscan despite it being disabled, you're pretty
> close to randomly choosing plans already, as the pruning doesn't work
> well anymore (as the %1 percent fuzz factor in
> compare_path_costs_fuzzily() swamps the actual plan costs).

Something I've wanted to do for awhile is to get rid of disable_cost
in favor of pruning disabled plans through logic rather than costing.
I've looked at this once or twice, and it seems doable but not entirely
trivial --- the sticky bits are places where you do need to allow a
disabled plan type because there's no other alternative.  But if we
could get that done, it'd help with this sort of problem.

			regards, tom lane

Commits

  1. Improve JIT docs.

  2. Add documentation for the JIT feature.

  3. Add EXPLAIN support for JIT.

  4. Add inlining support to LLVM JIT provider.

  5. JIT tuple deforming in LLVM JIT provider.

  6. Add FIELDNO_* macro designating offset into structs required for JIT.

  7. Add expression compilation support to LLVM JIT provider.

  8. Expand list of synchronized types and functions in LLVM JIT provider.

  9. Add helpers for emitting LLVM IR.

  10. Basic planner and executor integration for JIT.

  11. Debugging and profiling support for LLVM JIT provider.

  12. Support for optimizing and emitting code in LLVM JIT provider.

  13. Add file containing extensions of the LLVM C API.

  14. Basic JIT provider and error handling infrastructure.

  15. Add configure infrastructure (--with-llvm) to enable LLVM support.

  16. Add C++ support to configure.

  17. Add PGAC_PROG_VARCC_VARFLAGS_OPT autoconf macro.

  18. Fix VM buffer pin management in heap_lock_updated_tuple_rec().

  19. Allow tupleslots to have a fixed tupledesc, use in executor nodes.

  20. Expression evaluation based aggregate transition invocation.

  21. Perform slot validity checks in a separate pass over expression.

  22. Rely on executor utils to build targetlist for DML RETURNING.

  23. Refer to OS X as "macOS", except for the port name which is still "darwin".