Inspect the LLVM bitcode PostgreSQL generates with `jit_dump_bitcode`, or wire JIT-compiled functions into GDB and perf with `jit_debugging_support` and…

Every query locks every index on a table, even ones it doesn't use.

PostgreSQL's JIT compiler fires based on estimated query cost, but that estimate measures data volume, not expression complexity.

PostgreSQL's JIT compiler has two jobs: compiling expressions and deforming tuples. Here's how to isolate JIT bugs with two simple boolean toggles.

PostgreSQL's JIT compiler trades upfront compilation time for faster query execution—but it silently does nothing if the LLVM library isn't installed.

Choose your I/O execution engine with `io_method` and size the worker pool with `io_workers`—and yes, you can resize workers without restarting.

PostgreSQL 18's new io_max_concurrency caps per-process I/O operations in flight.

PostgreSQL 17 introduced read streams that combine adjacent disk blocks into larger I/O requests.

IntervalStyle changes how PostgreSQL parses interval input, not just formats output—and in one case, it silently flips the sign of your data.

Every PostgreSQL connection since 8.0 has heard the server announce `integer_datetimes`—a parameter that's had only one possible value since PostgreSQL 10.