No title

Started by Gregory S. Williamsonover 22 years ago30 messagesgeneral
Jump to latest
#1Gregory S. Williamson
gsw@globexplorer.com

One of our sysads sent this link ... wondering if there is any comment on it from the world of actual users of linux and a database.

<http://story.news.yahoo.com/news?tmpl=story&amp;cid=1738&amp;ncid=738&amp;e=9&amp;u=/zd/20030825/tc_zd/55311&gt;

Greg Williamson
DBA GlobeXplorer LLC

#2Ron Johnson
ron.l.johnson@cox.net
In reply to: Gregory S. Williamson (#1)
Linux ready for high-volume databases?

On Mon, 2003-08-25 at 16:28, Gregory S. Williamson wrote:

One of our sysads sent this link ... wondering if there is any comment on it from the world of actual users of linux and a database.

<http://story.news.yahoo.com/news?tmpl=story&amp;cid=1738&amp;ncid=738&amp;e=9&amp;u=/zd/20030825/tc_zd/55311&gt;

"Weak points include lack of available tools, ease of use and ease
of installation"

Sounds like he needs point-and-drool tools...

On the other hand, could even a beefy Linux 2.4 *today* system handle
a 24x7 500GB db that must process 6-8M OLTP-style transactions per
day, while also getting hit by report queries?

Don't think of this as a troll, because I really don't know, even
though I do know that MVS, OpenVMS & Solaris can. (I won't even
ask about toys like Windows and FreeBSD.)

--
-----------------------------------------------------------------
Ron Johnson, Jr. ron.l.johnson@cox.net
Jefferson, LA USA

"Knowledge should be free for all."
Harcourt Fenton Mudd, Star Trek:TOS, "I, Mudd"

#3Shridhar Daithankar
shridhar_daithankar@persistent.co.in
In reply to: Ron Johnson (#2)
Re: Linux ready for high-volume databases?

On 26 Aug 2003 at 2:55, Ron Johnson wrote:

On Mon, 2003-08-25 at 16:28, Gregory S. Williamson wrote:

One of our sysads sent this link ... wondering if there is any comment on it from the world of actual users of linux and a database.

<http://story.news.yahoo.com/news?tmpl=story&amp;cid=1738&amp;ncid=738&amp;e=9&amp;u=/zd/20030825/tc_zd/55311&gt;

"Weak points include lack of available tools, ease of use and ease
of installation"

Sounds like he needs point-and-drool tools...

On the other hand, could even a beefy Linux 2.4 *today* system handle
a 24x7 500GB db that must process 6-8M OLTP-style transactions per
day, while also getting hit by report queries?

If linux isn't limited to intel, probably yes. Of course, that does not carry
any weightage beyond an opinion. Probably on mainframe/postgresql it could
handle that..:-)

You have a monster database running. That is a proof. Well, I don't know of
any.

BTW, Tom mentioned couple of huge databases under postgresql, the 2u survey and
I forgot the other one. What they were running on?

Don't think of this as a troll, because I really don't know, even
though I do know that MVS, OpenVMS & Solaris can. (I won't even
ask about toys like Windows and FreeBSD.)

Well, given that Windows has more TPC-C spots at top than any single
combination, that remains a possibility if you have money...:-)

Bye
Shridhar

--
Peers's Law: The solution to a problem changes the nature of the problem.

#4Ron Johnson
ron.l.johnson@cox.net
In reply to: Shridhar Daithankar (#3)
Re: Linux ready for high-volume databases?

On Tue, 2003-08-26 at 03:06, Shridhar Daithankar wrote:

On 26 Aug 2003 at 2:55, Ron Johnson wrote:

On Mon, 2003-08-25 at 16:28, Gregory S. Williamson wrote:

One of our sysads sent this link ... wondering if there is any comment on it from the world of actual users of linux and a database.

<http://story.news.yahoo.com/news?tmpl=story&amp;cid=1738&amp;ncid=738&amp;e=9&amp;u=/zd/20030825/tc_zd/55311&gt;

"Weak points include lack of available tools, ease of use and ease
of installation"

Sounds like he needs point-and-drool tools...

On the other hand, could even a beefy Linux 2.4 *today* system handle
a 24x7 500GB db that must process 6-8M OLTP-style transactions per
day, while also getting hit by report queries?

If linux isn't limited to intel, probably yes. Of course, that does not carry

I think the worry is more about the kernel than anything else.
After all, an 8-way 2.8GHz Xeon w/ 16GB RAM and a bunch of 64-bit
66MHz PCI Ultra320 SCSI controllers or SAN HBAs can handle that much
database, I think.

--
-----------------------------------------------------------------
Ron Johnson, Jr. ron.l.johnson@cox.net
Jefferson, LA USA

"Experience hath shewn, that even under the best forms [of
government] those entrusted with power have, in time, and by
slow operations, perverted it into tyranny."
Thomas Jefferson

#5Dennis Gearon
gearond@fireserve.net
In reply to: Ron Johnson (#2)
Re: Linux ready for high-volume databases?

Free BSD may be a toy, maybe not, but it runs more of the webhosting
domains than any other OS.

Ron Johnson wrote:

Show quoted text

On Mon, 2003-08-25 at 16:28, Gregory S. Williamson wrote:

One of our sysads sent this link ... wondering if there is any comment on it from the world of actual users of linux and a database.

<http://story.news.yahoo.com/news?tmpl=story&amp;cid=1738&amp;ncid=738&amp;e=9&amp;u=/zd/20030825/tc_zd/55311&gt;

"Weak points include lack of available tools, ease of use and ease
of installation"

Sounds like he needs point-and-drool tools...

On the other hand, could even a beefy Linux 2.4 *today* system handle
a 24x7 500GB db that must process 6-8M OLTP-style transactions per
day, while also getting hit by report queries?

Don't think of this as a troll, because I really don't know, even
though I do know that MVS, OpenVMS & Solaris can. (I won't even
ask about toys like Windows and FreeBSD.)

#6Ron Johnson
ron.l.johnson@cox.net
In reply to: Dennis Gearon (#5)
Re: Linux ready for high-volume databases?

On Tue, 2003-08-26 at 10:00, Dennis Gearon wrote:

Free BSD may be a toy, maybe not, but it runs more of the webhosting
domains than any other OS.

That was supposed to be a joke. Putting FreeBSD in the same class
with Winblows is a prima facia absurdity, no matter how you cut it...

Ron Johnson wrote:

On Mon, 2003-08-25 at 16:28, Gregory S. Williamson wrote:

[snip]

though I do know that MVS, OpenVMS & Solaris can. (I won't even
ask about toys like Windows and FreeBSD.)

--
-----------------------------------------------------------------
Ron Johnson, Jr. ron.l.johnson@cox.net
Jefferson, LA USA

"Millions of Chinese speak Chinese, and it's not hereditary..."
Dr. Dean Edell

#7Vivek Khera
khera@kcilink.com
In reply to: Gregory S. Williamson (#1)
Re: Linux ready for high-volume databases?

"RJ" == Ron Johnson <ron.l.johnson@cox.net> writes:

RJ> Don't think of this as a troll, because I really don't know, even
RJ> though I do know that MVS, OpenVMS & Solaris can. (I won't even
RJ> ask about toys like Windows and FreeBSD.)

Well, you must be smoking something funny if you think FreeBSD is a
'toy' to be lumped in with windows....

I run a 24x7x365 db on FreeBSD which has *never* crashed in the 3
years it has been in production. Only downtime was the upgrade from
PG 7.1 to 7.2 and once for a switchover from RAID5 to RAID10. I *may*
have a few minutes of down time shortly when updating from PG 7.2 to
7.4 on a new box since I'm saturating the disk I/O bandwidth on the
old box. The eRServer software will be doing the data migration on
the live db so I don't have significant down time.

The DB is currently about 27Mb on disk (including indexes) and
processes several million inserts and updates daily, and a few million
deletes once every two weeks.

--
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Vivek Khera, Ph.D. Khera Communications, Inc.
Internet: khera@kciLink.com Rockville, MD +1-240-453-8497
AIM: vivekkhera Y!: vivek_khera http://www.khera.org/~vivek/

#8Al Hulaton
ahulaton@commandprompt.com
In reply to: Ron Johnson (#2)
Re: Linux ready for high-volume databases?

After seeing this article yesterday, I did a bit of research. One _big_ reason
why Sourceforge/VA/OSDN is moving over to IBM/Webshere/DB2 from PostgreSQL is
the resulting product will be jointly marketed by Sourceforge and IBM's
zillions of sales people. So not only will they get a shiny, new db, but
backend revenue.

"The companies will jointly market and sell the software as part of the
commercial agreement. "-- 4th paragraph, last sentence.
http://www.eweek.com/print_article/0,3668,a=30025,00.asp

"In a separate announcement today, VA Software announced a significant
commercial agreement with IBM focused on the joint marketing and sales of the
next generation of SourceForge™ Enterprise Edition." -- 7th paragram from
their press release at
http://www.vasoftware.com/news/press.php/2002/1070.html

Perhaps the PostgreSQL team bidding for the job, if any were even consulted,
didn't frame the project as IBM did -- a product joint venture. It's a good
tactic and I don't blame Sourceforge one bit for the opportunity.

The decision wasn't entirely technical so I don't see this as a loss for
PostgreSQL. DB2 isn't a slouch db by any means but not many companies will be
able to bargain with IBM as Sourceforge did. If you're a retailer in Topeka
with 3 locations, I doubt IBM would give you the same attention or joint
marketing deal they gave Sourceforge. DB2 ain't cheap.

--
Best,
Al Hulaton | Sr. Account Engineer | Command Prompt, Inc.
503.222.2783 | ahulaton@commandprompt.com
Home of Mammoth PostgreSQL and 'Practical PostgreSQL'
Managed PostgreSQL, Linux services and consulting
Read and Search O'Reilly's 'Practical PostgreSQL' at
http://www.commandprompt.com

#9Chris Browne
cbbrowne@acm.org
In reply to: Gregory S. Williamson (#1)
Re: Linux ready for high-volume databases?

After a long battle with technology,khera@kcilink.com (Vivek Khera), an earthling, wrote:

"RJ" == Ron Johnson <ron.l.johnson@cox.net> writes:

RJ> Don't think of this as a troll, because I really don't know, even
RJ> though I do know that MVS, OpenVMS & Solaris can. (I won't even
RJ> ask about toys like Windows and FreeBSD.)

Well, you must be smoking something funny if you think FreeBSD is a
'toy' to be lumped in with windows....

I suspect your irony-meter didn't get activated when it was supposed
to.

Please keep in mind that to the sorts of people that read and believe
and act on the source article, any system that doesn't have a vendor
to "certify" its fitness for database use is manifestly a "toy" that
only fools and Englishmen would use for any purpose that was the
slightest bit important.

Your injection of technical fact into the matter just confuses the
matter for people that prefer to get their "technical expertise" from
some white-paper-writer at the Gartner Group.

And there is a very slight bit of genuine technical reality to this,
too. People _assert_ that there are technical reasons to prefer
FreeBSD over other systems, but it is difficult to get forcibly past
the anecdotal evidence. The fact that you have had a system running,
apparently quite successfully, for a while, is not a _proof_ that
FreeBSD is more or less satisfactory than other OSes for the purpose.
It is merely an anecdote.

Unfortunately, we seldom see _anything_ better than anecdotes. People
report anecdotes that they heard that someone lost data to ext2.
Others report anecdotes that they have had good results with one
filesystem or another or one OS or another.

When there are problems, there isn't a good "certifiable" (or
'statistically significant') way of evaluating whether the faults
resulted from:
a) A PG bug
b) An OS filesystem bug
c) An OS device driver bug
d) Bad disk controller
e) Bad disk drive

It's quite easy for these to feed into one another so that a severe
problem combines together a tragedy of errors. (Been there :-(.) Is
there a way to "certify" that the composition of your particular
hardware with FreeBSD with PostgreSQL can't lead to tragedy? I'd
think not.

There's some pathos in with that irony...
--
http://cbbrowne.com/info/wp.html
Rules of the Evil Overlord #41. "Once my power is secure, I will
destroy all those pesky time-travel devices."
<http://www.eviloverlord.com/&gt;

#10Andrew Sullivan
andrew@libertyrms.info
In reply to: Al Hulaton (#8)
Re: Linux ready for high-volume databases?

On Tue, Aug 26, 2003 at 09:15:14AM -0700, Al Hulaton wrote:

Perhaps the PostgreSQL team bidding for the job, if any were even consulted,
didn't frame the project as IBM did -- a product joint venture. It's a good
tactic and I don't blame Sourceforge one bit for the opportunity.

Well, since the main point was to get some $$ into the company, bucks
which IBM has and PostgreSQL doesn't, it's not too surprising that
the PostgreSQL team didn't win. The move to DB2 was apparently a
quid pro quo for the cash.

A

-- 
----
Andrew Sullivan                         204-4141 Yonge Street
Liberty RMS                           Toronto, Ontario Canada
<andrew@libertyrms.info>                              M2P 2A8
                                         +1 416 646 3304 x110
#11scott.marlowe
scott.marlowe@ihs.com
In reply to: Al Hulaton (#8)
Re: Linux ready for high-volume databases?

On Tue, 26 Aug 2003, Al Hulaton wrote:

After seeing this article yesterday, I did a bit of research. One _big_ reason
why Sourceforge/VA/OSDN is moving over to IBM/Webshere/DB2 from PostgreSQL is
the resulting product will be jointly marketed by Sourceforge and IBM's
zillions of sales people. So not only will they get a shiny, new db, but
backend revenue.

"The companies will jointly market and sell the software as part of the
commercial agreement. "-- 4th paragraph, last sentence.
http://www.eweek.com/print_article/0,3668,a=30025,00.asp

"In a separate announcement today, VA Software announced a significant
commercial agreement with IBM focused on the joint marketing and sales of the
next generation of SourceForge™ Enterprise Edition." -- 7th paragram from
their press release at
http://www.vasoftware.com/news/press.php/2002/1070.html

Perhaps the PostgreSQL team bidding for the job, if any were even consulted,
didn't frame the project as IBM did -- a product joint venture. It's a good
tactic and I don't blame Sourceforge one bit for the opportunity.

The decision wasn't entirely technical so I don't see this as a loss for
PostgreSQL. DB2 isn't a slouch db by any means but not many companies will be
able to bargain with IBM as Sourceforge did. If you're a retailer in Topeka
with 3 locations, I doubt IBM would give you the same attention or joint
marketing deal they gave Sourceforge. DB2 ain't cheap.

Actually, I remember quite clearly the incredibly bad performance of
sourceforge's search engine for the better part of a year after switching
out postgresql for db2. It had been quite snappy, and I could enter
database or some other keyword and have a page display in ~2 seconds or
less. For the first three months or so after the switch, most searchs
simply timed out to PHP's default 30 seconds. Even when they got it
working better, it only had maybe 1/10th or less of the keywords indexed
that they had had in postgresql (i.e. words like index or email weren't
being indexed. :-)

It was probably at least 9 months later that the search engine was finally
back to being usable, and another 3 or 4 before it was about as good as
postgresql. And we're talking an older version (I believe it was 7.1) of
postgresql as well.

The switch to db2 was driven by partnering business needs, not by poor
performance of postgresql.

#12Bruce Momjian
bruce@momjian.us
In reply to: Vivek Khera (#7)
Re: Linux ready for high-volume databases?

Vivek Khera <khera@kcilink.com> writes:

I run a 24x7x365 db on FreeBSD which has *never* crashed in the 3
years it has been in production. Only downtime was the upgrade from
PG 7.1 to 7.2 and once for a switchover from RAID5 to RAID10.

I would be interested to know what backup strategy you use for this. Without
online backups this means that if you had crashed you would have lost data up
to the last pg_dump you took? Had you done tests to see how long it would have
taken to restore from the pg_dump?

Online backups with archived transaction logs are the next big killer feature
(the last one remaining?) for 24x7 operation I think.

The DB is currently about 27Mb on disk (including indexes) and
processes several million inserts and updates daily, and a few million
deletes once every two weeks.

Oh, it's a really small database. That helps a lot with the backup problems of
24x7 operation. Still I would be interested.

--
greg

#13Jonathan Bartlett
johnnyb@eskimo.com
In reply to: Bruce Momjian (#12)
Re: Linux ready for high-volume databases?

Online backups with archived transaction logs are the next big killer feature
(the last one remaining?) for 24x7 operation I think.

I believe this is at least theoretically possible using Linux device layer
tricks. Using network block devices, you can have a network RAID1, with
the transaction logs living over NFS. Never tried this, but it seems all
the tools are there.

#14Maksim Likharev
mlikharev@aurigin.com
In reply to: Jonathan Bartlett (#13)
Re: Linux ready for high-volume databases?

Don't think of this as a troll, because I really don't know, even
though I do know that MVS, OpenVMS & Solaris can. (I won't even
ask about toys like Windows and FreeBSD.)

What so toy in Windows?
With some experience on huge DBs,
one on Windows ( MS SQL 2K ) works x1.5/2 faster, than one on Linux/Sun
( pg 7.3.3 ).
Read-only transactions tho.

Is Linux ready for big dbs, I would say yes, with new kernel I say
definitely yes.

#15Oleg Bartunov
oleg@sai.msu.su
In reply to: scott.marlowe (#11)
Re: Linux ready for high-volume databases?

On Tue, 26 Aug 2003, scott.marlowe wrote:

On Tue, 26 Aug 2003, Al Hulaton wrote:

After seeing this article yesterday, I did a bit of research. One _big_ reason
why Sourceforge/VA/OSDN is moving over to IBM/Webshere/DB2 from PostgreSQL is
the resulting product will be jointly marketed by Sourceforge and IBM's
zillions of sales people. So not only will they get a shiny, new db, but
backend revenue.

"The companies will jointly market and sell the software as part of the
commercial agreement. "-- 4th paragraph, last sentence.
http://www.eweek.com/print_article/0,3668,a=30025,00.asp

"In a separate announcement today, VA Software announced a significant
commercial agreement with IBM focused on the joint marketing and sales of the
next generation of SourceForgeО©╫О©╫О©╫ Enterprise Edition." -- 7th paragram from
their press release at
http://www.vasoftware.com/news/press.php/2002/1070.html

Perhaps the PostgreSQL team bidding for the job, if any were even consulted,
didn't frame the project as IBM did -- a product joint venture. It's a good
tactic and I don't blame Sourceforge one bit for the opportunity.

The decision wasn't entirely technical so I don't see this as a loss for
PostgreSQL. DB2 isn't a slouch db by any means but not many companies will be
able to bargain with IBM as Sourceforge did. If you're a retailer in Topeka
with 3 locations, I doubt IBM would give you the same attention or joint
marketing deal they gave Sourceforge. DB2 ain't cheap.

Actually, I remember quite clearly the incredibly bad performance of
sourceforge's search engine for the better part of a year after switching
out postgresql for db2. It had been quite snappy, and I could enter
database or some other keyword and have a page display in ~2 seconds or
less. For the first three months or so after the switch, most searchs
simply timed out to PHP's default 30 seconds. Even when they got it
working better, it only had maybe 1/10th or less of the keywords indexed
that they had had in postgresql (i.e. words like index or email weren't
being indexed. :-)

It was probably at least 9 months later that the search engine was finally
back to being usable, and another 3 or 4 before it was about as good as
postgresql. And we're talking an older version (I believe it was 7.1) of
postgresql as well.

The switch to db2 was driven by partnering business needs, not by poor
performance of postgresql.

It's interesting to get projects metadata so I could setup simple
tsearch2 based full text search and see how it could be fast now.

---------------------------(end of broadcast)---------------------------
TIP 8: explain analyze is your friend

Regards,
Oleg
_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83

#16Dennis Gearon
gearond@fireserve.net
In reply to: Bruce Momjian (#12)
Re: Linux ready for high-volume databases?

With the low cost of disks, it might be a good idea to just copy to
disks, that one can put back in.

Greg Stark wrote:

Show quoted text

Vivek Khera <khera@kcilink.com> writes:

I run a 24x7x365 db on FreeBSD which has *never* crashed in the 3
years it has been in production. Only downtime was the upgrade from
PG 7.1 to 7.2 and once for a switchover from RAID5 to RAID10.

I would be interested to know what backup strategy you use for this. Without
online backups this means that if you had crashed you would have lost data up
to the last pg_dump you took? Had you done tests to see how long it would have
taken to restore from the pg_dump?

Online backups with archived transaction logs are the next big killer feature
(the last one remaining?) for 24x7 operation I think.

The DB is currently about 27Mb on disk (including indexes) and
processes several million inserts and updates daily, and a few million
deletes once every two weeks.

Oh, it's a really small database. That helps a lot with the backup problems of
24x7 operation. Still I would be interested.

#17Bruce Momjian
bruce@momjian.us
In reply to: Dennis Gearon (#16)
Re: Linux ready for high-volume databases?

Dennis Gearon <gearond@fireserve.net> writes:

With the low cost of disks, it might be a good idea to just copy to disks, that
one can put back in.

Uh, sure, using hardware raid 1 and breaking one set of drives out of the
mirror to perform the backup is an old trick. And for small databases backups
are easy that way. Just store a few dozen copies of the pg_dump output on your
live disks for local backups and burn CD-Rs for offsite backups.

But when you have hundreds of gigabytes of data and you want to be able to
keep multiple snapshots of your database both on-site and off-site... No, you
can't just buy another hard drive and call it a business continuity plan.

As it turns out my current project will be quite small. I may well be adopting
the first approach. I'm thinking taking a pg_dump regularly (nightly if I can
get away with doing it that infrequently) keeping the past n dumps, and
burning a CD with those dumps.

This doesn't provide what online backups do, of recovery to the minute of the
crash. And I get nervous having only logical pg_dump output, no backups of the
actual blocks on disk. But is that what everybody does?

--
greg

#18Shridhar Daithankar
shridhar_daithankar@persistent.co.in
In reply to: Ron Johnson (#4)
Re: Linux ready for high-volume databases?

On 26 Aug 2003 at 8:12, Ron Johnson wrote:

On Tue, 2003-08-26 at 03:06, Shridhar Daithankar wrote:

If linux isn't limited to intel, probably yes. Of course, that does not carry

I think the worry is more about the kernel than anything else.
After all, an 8-way 2.8GHz Xeon w/ 16GB RAM and a bunch of 64-bit
66MHz PCI Ultra320 SCSI controllers or SAN HBAs can handle that much
database, I think.

Hmm.. I would say a 64 bit CPU will make a difference as well.

I am impressed by 2.6. Yesterday I installed 2.6.0-test4. Full postgresql CVS
head compile took 9 min 18 sec on 2.4.20 and 7 min 14 sec on 2.6.0-test4.
Impressive.

I am going to run pgbench on it. That will add another dimention to 7.3.4 v/s
7.4beta1 performance bouts.

Bye
Shridhar

--
Bizoos, n.: The millions of tiny individual bumps that make up a basketball. --
Rich Hall, "Sniglets"

#19Shridhar Daithankar
shridhar_daithankar@persistent.co.in
In reply to: Al Hulaton (#8)
Re: Linux ready for high-volume databases?

On 26 Aug 2003 at 9:15, Al Hulaton wrote:

After seeing this article yesterday, I did a bit of research. One _big_ reason
why Sourceforge/VA/OSDN is moving over to IBM/Webshere/DB2 from PostgreSQL is
the resulting product will be jointly marketed by Sourceforge and IBM's
zillions of sales people. So not only will they get a shiny, new db, but
backend revenue.

"The companies will jointly market and sell the software as part of the
commercial agreement. "-- 4th paragraph, last sentence.
http://www.eweek.com/print_article/0,3668,a=30025,00.asp

<From vague memory somewhere from some article>

One of the technical reasons sourceforge went to DB2 was that DB2 had
clustering. Postgresql could not scale beyond single machine and on single
machine it had limitations on scaling as well.

Note that this was done quite a while back. Today postgresql might be as
scalable as required by sourceforge but they needed it then and had to move.

</From vague memory somewhere from some article>

<rant>
However if DB clustering was the problem, personally I would have split the
data on two machines on two different databases and had an app consolidate that
data. The efforts in rewriting app. could have been well compensated for
performance hit sourceforge took immediately after the move.

But that's me..
<rant>

Bye
Shridhar

--
There are always alternatives. -- Spock, "The Galileo Seven", stardate 2822.3

#20Ron Johnson
ron.l.johnson@cox.net
In reply to: Bruce Momjian (#17)
Re: Linux ready for high-volume databases?

On Tue, 2003-08-26 at 23:35, Greg Stark wrote:

Dennis Gearon <gearond@fireserve.net> writes:

[snip]

This doesn't provide what online backups do, of recovery to the minute of the
crash. And I get nervous having only logical pg_dump output, no backups of the
actual blocks on disk. But is that what everybody does?

Gak!! It can never be guaranteed that the "actual blocks on disk"
are transactionally consistent. Thus, the pg_dump output is suff-
icient.

However, there is still the large problem of PITR. Unless you
double your h/w and run Postgresql-R, you can not guarantee recov-
ery to an exact point in time if there is a hardware failure that
destroys the database.

Therefore, you can only restore databases to the time that the
last pg_dump was taken.

--
-----------------------------------------------------------------
Ron Johnson, Jr. ron.l.johnson@cox.net
Jefferson, LA USA

The difference between Rock&Roll and Country Music?
Old Rockers still on tour are pathetic, but old Country singers
are still great.

#21Andrew Sullivan
andrew@libertyrms.info
In reply to: Bruce Momjian (#17)
#22Vivek Khera
khera@kcilink.com
In reply to: Gregory S. Williamson (#1)
#23Vivek Khera
khera@kcilink.com
In reply to: Gregory S. Williamson (#1)
#24Vivek Khera
khera@kcilink.com
In reply to: Gregory S. Williamson (#1)
#25Vivek Khera
khera@kcilink.com
In reply to: Gregory S. Williamson (#1)
#26Alvaro Herrera
alvherre@dcc.uchile.cl
In reply to: Vivek Khera (#22)
#27Vivek Khera
khera@kcilink.com
In reply to: Alvaro Herrera (#26)
#28Dennis Gearon
gearond@fireserve.net
In reply to: Vivek Khera (#23)
#29Steve Lane
slane@moyergroup.com
In reply to: Ron Johnson (#20)
#30Bruce Momjian
bruce@momjian.us
In reply to: Steve Lane (#29)