[table partitioning] How many partitions are possibel?
Hello *,
Long time ago I used VIEWs on my history database and when PostgreSQL
introduced table partitioning I was switching to it.
Currently I use Debian GNU/Linux 7.11 with PostgreSQL 9.1 (table space
and table partitioning) using an Adaptec 16-Channel Raid-1 Controller
with 16x 6 TByte SAS UltraStar (HGST) drives.
I created partitions of 100 years range and have currently 132 of them.
There are 8 base columns (1 data colum in english) and then for each
language used an additional colum. Some of the data where translated
into 27 languages but I have 56 non-english columns.
So in total I have currently 64 columns and arround 156mio rows.
Th etables are organised into
history_earth
history_earth_021_a
history_earth_020_a
history_earth_019_a
...
history_earth_124_b
...
"a" mean A.C. and "b" B.C.
While checking my Root-Servers I discovered, that my PostgreSQL Box has
a huge performance problem, because some table partitions became VERY
large (3 table partitions exceed already 1 TByte and 14 are 500-1000GB).
I like to make the partitions smaller, but the documentation say, you
should not dare to make several 1000 partitions..
Question:
What is with is today possibel with table partitioning?
And there is another thing:
The 16 "new" SAS Drives where sponsored, hence free for me including the
new Raid-1 Controller, but I do not like the idea, to have a singel
physical database of arround 40 TByte diskspace...
I can get much less expensive (not cheaper) SAS drives of 1 or 2 TByte
and since the Raid-1 Controller cost only 400�, I can use several LOW
POWER machines (Mini-ITX) to accomplish the task because the webinterface
is anyway stored on a seperated server.
Any suggestions?
--
Michelle Konzack
00372-54541400
On Tue, Dec 26, 2017 at 11:04:55AM +0100, Michelle Konzack wrote:
I like to make the partitions smaller, but the documentation say, you
should not dare to make several 1000 partitions..
Even more than a hundred may be already risky in my opinion here. The
issue with a large number of partitioning using the pre-9.6 grammar
comes from the planning time which sky-rockets because the optimizer
uses a O(N^2) algorithm to consider all the partitions. The v10 grammar
does not take care of this planning problem as far as I recall, but v11
gets that better for partition-wise joins if my memory does not fail me.
--
Michael
Hi,
Am 2017-12-26 hackte Michael Paquier in die Tasten:
------------------------------------------------------------------------
On Tue, Dec 26, 2017 at 11:04:55AM +0100, Michelle Konzack wrote:
I like to make the partitions smaller, but the documentation say, you
should not dare to make several 1000 partitions..Even more than a hundred may be already risky in my opinion here. The
issue with a large number of partitioning using the pre-9.6 grammar
comes from the planning time which sky-rockets because the optimizer
uses a O(N^2) algorithm to consider all the partitions. The v10 grammar
does not take care of this planning problem as far as I recall, but v11
gets that better for partition-wise joins if my memory does not fail me.
--
Michael
I think on migrating to v10, but I have to backport the PostgreSQL.
Currently I am thinking about hot to backup 28 TByte of data...
Have to dump and compress table by table and thios take endless time,
especially, if I am in Estonia and the database is in Germany.
Is there already a rease date for v11?
Thanks in avance
--
Michelle Konzack
00372-54541400
On Wed, Dec 27, 2017 at 08:53:11AM +0100, Michelle Konzack wrote:
Is there already a release date for v11?
Based on the pace of the most recent major releases, this could happen
around September. This depends on any issues encountered
post-development though.
--
Michael
Thanks for the info.
I think, it is not worth to do the migration to v10 now
and then some month later to v11.
I hope, my v9.1 will survive the version jump.
What do you think?
My database has no complex things in it. I keept it realy
on basic level to avoid problems if I have to upgrade.
Thanks in avance
Am 2017-12-27 hackte Michael Paquier in die Tasten:
On Wed, Dec 27, 2017 at 08:53:11AM +0100, Michelle Konzack wrote:
Is there already a release date for v11?
Based on the pace of the most recent major releases, this could happen
around September. This depends on any issues encountered
post-development though.
--
Michael
--
Michelle Konzack
00372-54541400