| From: | Robert Haas <robertmhaas(at)gmail(dot)com> |
|---|---|
| To: | Kouhei Kaigai <kaigai(at)ak(dot)jp(dot)nec(dot)com> |
| Cc: | "pgsql-hackers(at)postgreSQL(dot)org" <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: DBT-3 with SF=20 got failed |
| Date: | 2015-06-11 14:28:48 |
| Message-ID: | CA+TgmoaKP2g6oTiYvpqc64Bhxt_7ncbeYR3fNmg7h-4sVQwxMA@mail.gmail.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On Wed, Jun 10, 2015 at 10:57 PM, Kouhei Kaigai <kaigai(at)ak(dot)jp(dot)nec(dot)com> wrote:
> The attached patch replaces this palloc0() by MemoryContextAllocHuge() + memset().
> Indeed, this hash table is constructed towards the relation with nrows=119994544,
> so, it is not strange even if hash-slot itself is larger than 1GB.
You forgot to attach the patch, I think. It looks to me like the size
of a HashJoinTuple is going to be 16 bytes, so 1GB/16 = ~64 million.
That's a lot of buckets, but maybe not unreasonably many if you've got
enough memory.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Kohei KaiGai | 2015-06-11 14:28:52 | Re: DBT-3 with SF=20 got failed |
| Previous Message | Jan Wieck | 2015-06-11 14:20:10 | Re: DBT-3 with SF=20 got failed |