Horton

Re: [HACKERS] Parallel Append implementation

Rafia Sabih <rafia.sabih@enterprisedb.com>

View thread View on postgr.es
From: Rafia Sabih <rafia.sabih@enterprisedb.com>
To: Amit Khandekar <amitdkhan.pg@gmail.com>
Cc: Robert Haas <robertmhaas@gmail.com>, Amit Kapila <amit.kapila16@gmail.com>, Andres Freund <andres@anarazel.de>, Ashutosh Bapat <ashutosh.bapat@enterprisedb.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2017-11-21T07:14:09Z
Lists: pgsql-hackers 
On Mon, Nov 13, 2017 at 12:54 PM, Amit Khandekar <amitdkhan.pg@gmail.com> wrote:
> Thanks a lot Robert for the patch. I will have a look. Quickly tried
> to test some aggregate queries with a partitioned pgbench_accounts
> table, and it is crashing. Will get back with the fix, and any other
> review comments.
>
> Thanks
> -Amit Khandekar

I was trying to get the performance of this patch at commit id -
11e264517dff7a911d9e6494de86049cab42cde3 and TPC-H scale factor 20
with the following parameter settings,
work_mem = 1 GB
shared_buffers = 10GB
effective_cache_size = 10GB
max_parallel_workers_per_gather = 4
enable_partitionwise_join = on

and the details of the partitioning scheme is as follows,
tables partitioned = lineitem on l_orderkey and orders on o_orderkey
number of partitions in each table = 10

As per the explain outputs PA was used in following queries- 1, 3, 4,
5, 6, 7, 8, 10, 12, 14, 15, 18, and 21.
Unfortunately, at the time of executing any of these query, it is
crashing with the following information in  core dump of each of the
workers,

Program terminated with signal 11, Segmentation fault.
#0  0x0000000010600984 in pg_atomic_read_u32_impl (ptr=0x3ffffec29294)
at ../../../../src/include/port/atomics/generic.h:48
48 return ptr->value;

In case this a different issue as you pointed upthread, you may want
to have a look at this as well.
Please let me know if you need any more information in this regard.



-- 
Regards,
Rafia Sabih
EnterpriseDB: http://www.enterprisedb.com/

Commits

  1. Update parallel.sgml for Parallel Append

  2. Support Parallel Append plan nodes.

  3. Remove BufFile's isTemp flag.

  4. Improve comments for parallel executor estimation functions.

  5. Separate reinitialization of shared parallel-scan state from ExecReScan.

  6. Eat XIDs more efficiently in recovery TAP test.

  7. Avoid syntax error on platforms that have neither LOCALE_T nor ICU.

  8. Preparatory refactoring for parallel merge join support.