On Mon, Jul 30, 2018 at 3:02 PM, Andres Freund <andres@xxxxxxxxxxx> wrote:
Cheers,
Hi,
On 2018-07-30 13:31:33 -0400, Jeff Janes wrote:
> I don't know where the time is going with the as-committed JIT. None of
> the JIT-specific timings reported by EXPLAIN (ANALYZE) add up to anything
> close to the slow-down I'm seeing. Shouldn't compiling and optimization
> time show up there?
As my timings showed, I don't see the slowdown you're reporting. Could
you post a few EXPLAIN ANALYZEs?
I don't think you showed any timings where jit_above_cost < query cost < jit_optimize_above_cost, which is where I saw the slow down. (That is also where things naturally land for me using default settings)
I've repeated my test case on a default build (./configure --with-llvm --prefix=....) and default postgresql.conf, using the post-11BETA2 commit 5a71d3e.
I've attached the full test case, and the full output.
Here are the last two executions, with jit=on and jit=off, respectively. Doing it with TIMING OFF doesn't meaningfully change things, nor does increasing shared_buffers beyond the default.
QUERY PLAN
--------------------------------------------------------------------------------------------------------------------------
Seq Scan on i200c200 (cost=0.00..233332.28 rows=9999828 width=16) (actual time=29.317..11966.291 rows=10000000 loops=1)
Planning Time: 0.034 ms
JIT:
Functions: 2
Generation Time: 1.589 ms
Inlining: false
Inlining Time: 0.000 ms
Optimization: false
Optimization Time: 9.002 ms
Emission Time: 19.948 ms
Execution Time: 12375.493 ms
(11 rows)
Time: 12376.281 ms (00:12.376)
SET
Time: 1.955 ms
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------
Seq Scan on i200c200 (cost=0.00..233332.28 rows=9999828 width=16) (actual time=0.063..3897.302 rows=10000000 loops=1)
Planning Time: 0.037 ms
Execution Time: 4292.400 ms
(3 rows)
Time: 4293.196 ms (00:04.293)
Cheers,
Jeff
Attachment:
wide.sql
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