Обсуждение: Ultra-cheap NVRAM device
I thought this might be interesting, not the least due to the extremely low price ($150 + the price of regular DIMMs): http://www.tomshardware.com/storage/20050907/index.html Anybody know a good reason why you can't put a WAL on this, and enjoy a hefty speed boost for a fraction of the price of a traditional SSD? (Yes, it's SATA, not PCI, so the throughput is not all that impressive -- but still, it's got close to zero seek time.) /* Steinar */ -- Homepage: http://www.sesse.net/
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi, on a 7.2 System (Suse-Linux) I got an error "duplicate key in unique index pg_statistic_relid_att_index" (think it was while vacuuming) I REINDEXd the database. Now the table pg_statistic_relid_att_index is completely gone. Has anybody an advise? tia, Harald -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (MingW32) Comment: GnuPT 2.7.2 iQEVAwUBQ0Ejx3fX3+fgcdKcAQIVoQf+MFnt+U65FPNxQjHwZ15eT13NwBoCsOE9 d3nFaKTG58SmI9QziMt1Tpo+pD89LMQZacnCRDv/M3Tz6ruSQaPIsxS6m1evKjq7 7ixSRCwD+41C2x27qSRZDOEUt6AvG5xfSv43NxJQNS/zB+/TnQ3wGXzwdRrRQiQE Mv6DXv5s+3Wrbg9qG78Xn3mHOGGySFSG1x9ItUoST+jC6a7rOl5YL3wDCacdgve/ pzq3fe6+JYjEQyKFxEzZYJidsWvr9C7EKfc321PYBscuPNyGMU1Vohe8kDYFbyeG L23jXPV8c7WO2w4aQMdQr6V9YXtnBeMgGdAFjo4My29xbdepkwOUvw== =I8Ax -----END PGP SIGNATURE-----
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 > on a 7.2 System (Suse-Linux) I got an error "duplicate key in unique > index pg_statistic_relid_att_index" (think it was while vacuuming) > > I REINDEXd the database. > Now the table pg_statistic_relid_att_index is completely gone. go searching the internet first, man ... Surprisingly I'm not the first one having such a breakdown Found a solution provided by Tom Lane: http://www.xy1.org/pgsql-general@postgresql.org/msg04568.html Seems to work, many thanks Sorry for the overhasty question Harald -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (MingW32) Comment: GnuPT 2.7.2 iQEVAwUBQ0E5nXfX3+fgcdKcAQJWsgf+JvgWRjgl/RLBzGd8wNt7x6/VngGOzdpT 4E3OgbrGuAPEC3INkMLTLRU2hVvjRqgkNaWS2YlXpFmlAff6czGeSbwXv4vDiiH7 AYHpONACLgr8jcHohS0kmylqu/3QYSsmRBDOTOCNms1iMEmJZvpru9YJpSEjwWUL /n5pu5lurcpU+VGLTCikin5UnsNWmQzsegz+f2co3UuTDHIUER+W2538Fb9iiZBD P9TCI972U+oC2YTg+Puh22jPfS1gG7EHUxKt/XbE9klca1AnCdJX6LdsIh7vdMhw 6u8JzaaAz9nHtqYFpClkEpnkp9KEohw/uQyDUCB7FK//MRtSWx+MPw== =52pe -----END PGP SIGNATURE-----
Harald Lau <harald@sector-x.de> writes:
> on a 7.2 System (Suse-Linux) I got an error "duplicate key in unique
> index pg_statistic_relid_att_index" (think it was while vacuuming)
> I REINDEXd the database.
> Now the table pg_statistic_relid_att_index is completely gone.
> Has anybody an advise?
Dump, initdb, reload. You've probably got more problems than just
that. This might be a good time to update to something newer than
PG 7.2, too.
regards, tom lane
On Oct 3, 2005, at 5:02 AM, Steinar H. Gunderson wrote: > I thought this might be interesting, not the least due to the > extremely low > price ($150 + the price of regular DIMMs): > > > This has been posted before, and the main reason nobody got very excited is that: a) it only uses the PCI bus to provide power to the device, not for I/O b) It is limited to SATA bandwidth c) The benchmarks did not prove it to be noticeably faster than a good single SATA drive A few of us were really excited at first too, until seeing the benchmarks.. -Dan
On Oct 3, 2005, at 5:02 AM, Steinar H. Gunderson wrote: > I thought this might be interesting, not the least due to the > extremely low > price ($150 + the price of regular DIMMs): > > Replying before my other post came through.. It looks like their benchmarks are markedly improved since the last article I read on this. There may be more interest now.. -Dan
On Mon, 2005-10-03 at 11:15 -0600, Dan Harris wrote: > On Oct 3, 2005, at 5:02 AM, Steinar H. Gunderson wrote: > > > I thought this might be interesting, not the least due to the > > extremely low > > price ($150 + the price of regular DIMMs): > > > > > > > > This has been posted before, and the main reason nobody got very > excited is that: > > a) it only uses the PCI bus to provide power to the device, not for I/O > b) It is limited to SATA bandwidth > c) The benchmarks did not prove it to be noticeably faster than a > good single SATA drive > > A few of us were really excited at first too, until seeing the > benchmarks.. Also, no ECC support. You'd be crazy to use it for anything. -jwb
Nah. It's still not right. It needs: 1= full PCI, preferably at least 64b 133MHz PCI-X, bandwidth. A RAM card should blow the doors off the fastest commodity RAID setup you can build. 2= 8-16 DIMM slots 3= a standard battery type that I can pick up spares for easily 4= ECC support If it had all those features, I'd buy it at even 2x or possibly even 3x it's current price. 8, 16, or 32GB (using 1, 2, or 4GB DIMMs respectively in an 8 slot form factor) of very fast temporary work memory (sorting anyone ;-) ). Yum. Ron -----Original Message----- From: Dan Harris <fbsd@drivefaster.net> Sent: Oct 3, 2005 1:21 PM To: pgsql-performance@postgresql.org Subject: Re: [PERFORM] Ultra-cheap NVRAM device On Oct 3, 2005, at 5:02 AM, Steinar H. Gunderson wrote: > I thought this might be interesting, not the least due to the > extremely low > price ($150 + the price of regular DIMMs): > > Replying before my other post came through.. It looks like their benchmarks are markedly improved since the last article I read on this. There may be more interest now.. -Dan ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend
On Oct 3, 2005, at 7:02 AM, Steinar H. Gunderson wrote: > Anybody know a good reason why you can't put a WAL on this, and > enjoy a hefty > speed boost for a fraction of the price of a traditional SSD? (Yes, > it's > SATA, not PCI, so the throughput is not all that impressive -- but > still, > it's got close to zero seek time.) > old news. discussed here a while back. the board you see has no ECC. Would you trust > 1GB RAM to not have ECC for more than 1 month? You're almost guaranteed at least 1 bit error.
There was a discussion about this about 2 months ago. See the archives. On Mon, Oct 03, 2005 at 01:02:26PM +0200, Steinar H. Gunderson wrote: > I thought this might be interesting, not the least due to the extremely low > price ($150 + the price of regular DIMMs): > > http://www.tomshardware.com/storage/20050907/index.html > > Anybody know a good reason why you can't put a WAL on this, and enjoy a hefty > speed boost for a fraction of the price of a traditional SSD? (Yes, it's > SATA, not PCI, so the throughput is not all that impressive -- but still, > it's got close to zero seek time.) > > /* Steinar */ > -- > Homepage: http://www.sesse.net/ > > ---------------------------(end of broadcast)--------------------------- > TIP 3: Have you checked our extensive FAQ? > > http://www.postgresql.org/docs/faq > -- Jim C. Nasby, Sr. Engineering Consultant jnasby@pervasive.com Pervasive Software http://pervasive.com work: 512-231-6117 vcard: http://jim.nasby.net/pervasive.vcf cell: 512-569-9461
fbsd@drivefaster.net (Dan Harris) writes:
> On Oct 3, 2005, at 5:02 AM, Steinar H. Gunderson wrote:
>
>> I thought this might be interesting, not the least due to the
>> extremely low
>> price ($150 + the price of regular DIMMs):
>
> Replying before my other post came through.. It looks like their
> benchmarks are markedly improved since the last article I read on
> this. There may be more interest now..
It still needs a few more generations worth of improvement.
1. It's still limited to SATA speed
2. It's not ECC smart
What I'd love to see would be something that much smarter, or, at
least, that pushes the limits of SATA speed, and which has both a
battery on board and enough CF storage to cope with outages.
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Chris wrote: > fbsd@drivefaster.net (Dan Harris) writes: > > On Oct 3, 2005, at 5:02 AM, Steinar H. Gunderson wrote: > > > >> I thought this might be interesting, not the least due to the > >> extremely low > >> price ($150 + the price of regular DIMMs): > > > > Replying before my other post came through.. It looks like their > > benchmarks are markedly improved since the last article I read on > > this. There may be more interest now.. > > It still needs a few more generations worth of improvement. > > 1. It's still limited to SATA speed > 2. It's not ECC smart 3. Another zero (or two) on the price tag :). While it looks like a fun toy to play with, for it to replace hard drives in server environments they need to provide more emphasis and effort in assuring people their drive is reliable. If they really wanted it to be adopted in server environments, it would have been packaged in a 3.5" drive, not a pci card, since that's what we all hot swap (especially since it already uses SATA interface). They would also have allowed use of 2 and 4gb DIMS, and put in a small hard drive that the memory paged to when powered off, and completely isolated the power supply...hard to pack all that in 60$. That said, we are in the last days of the hard disk. I think it is only a matter of months before we see a sub 1000$ part which have zero latency in the 20-40 GB range. Once that happens economies of scale will kick in and hard drives will become basically a backup device. Merlin