| From: | Thomas Munro <thomas(dot)munro(at)enterprisedb(dot)com> |
|---|---|
| To: | Pg Hackers <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Registering LWTRANCHE_PARALLEL_HASH_JOIN |
| Date: | 2018-02-10 23:07:20 |
| Message-ID: | CAEepm=1WM=02cKT7hinnx8xRhN2QdF+WfE6gk5oMPorwLi+XiA@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
Hi,
I forgot to register a display name for LWTRANCHE_PARALLEL_HASH_JOIN,
the tranche ID used by the LWLock that Parallel Hash uses when handing
out chunks of memory. Please see attached.
It's rare for this LWLock to show up in pg_stat_activity, but if you
stick pg_usleep(10000) into ExecParallelHashTupleAlloc() after the
lock is acquired (the slow path where a new 32KB chunk is needed) and
run some parallel hash joins, then you'll see that pg_stat_activity
reports that as "extension" in unpatched master.
--
Thomas Munro
http://www.enterprisedb.com
| Attachment | Content-Type | Size |
|---|---|---|
| 0001-Register-and-document-LWTRANCHE_PARALLEL_HASH_JOIN.patch | application/octet-stream | 2.3 KB |
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Peter Geoghegan | 2018-02-10 23:11:43 | Re: JIT compiling with LLVM v9.0 |
| Previous Message | Tom Lane | 2018-02-10 21:24:31 | Re: postgres_fdw: perform UPDATE/DELETE .. RETURNING on a join directly |