Re: [sqlite] Why would batched write operations NOT be faster than individual ones

>And as far as I know, even the most expensive hardware RAID controllers >and disks do not yet support multi-disk transactions, so your reference >to not-yet existing hardware is moot. They all do, unless the I/O was designed by a moron. Of course, morons are the most plentiful element in the

Re: [sqlite] Why would batched write operations NOT be faster than individual ones

Hi, Von: sqlite-users-boun...@sqlite.org [mailto:sqlite-users-boun...@sqlite.org] > At 21:35 03/03/2014, you wrote: > ´¯¯¯ > >RAID3-4-5 was great when disks were expensive, in 80's an 90's. Now > >not. A minimal RAID5 needs 3 disks. A minimal RAID10 4. An enterprise > >disk SAS 15Krpm 146 GB 6G

Re: [sqlite] Why would batched write operations NOT be faster than individual ones

>Another way to bust your data is to rely on RAID 5 or 6 or similar, at >least if the software does not take special care. > >When those mechanisms, updating a block always results in at least 2 disk >writes: The data block and the checksum block. There's a small time >window where only one of

Re: [sqlite] Why would batched write operations NOT be faster than individual ones

At 21:35 03/03/2014, you wrote: ´¯¯¯ RAID3-4-5 was great when disks were expensive, in 80's an 90's. Now not. A minimal RAID5 needs 3 disks. A minimal RAID10 4. An enterprise disk SAS 15Krpm 146 GB 6G is $350, and a not enterprise grade cheaper and bigger. Now RAID1E and RAID10E give more

Re: [sqlite] Why would batched write operations NOT be faster than individual ones

On Mon, 03 Mar 2014 17:36:10 +0100 Jean-Christophe Deschamps wrote: > > >It's how RAID5 works. Check this page docs http://baarf.com/ about > >it. > > This is utter BS. No. > Serious RAID controllers perform parallel I/O on as many drives that > are making up a given

Re: [sqlite] Why would batched write operations NOT be faster than individual ones

-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On 03/03/14 03:00, Simon Slavin wrote: > What the heck ? Is this a particular implementation of RAID ... The technical term is "write hole" and can occur at many RAID levels: http://www.raid-recovery-guide.com/raid5-write-hole.aspx You can

Re: [sqlite] Why would batched write operations NOT be faster than individual ones

It's how RAID5 works. Check this page docs http://baarf.com/ about it. This is utter BS. Serious RAID controllers perform parallel I/O on as many drives that are making up a given array. Of course I'm talking of SAS drives here with battery backed-up controller. Kid sister RAID5-6

Re: [sqlite] Why would batched write operations NOT be faster than individual ones

On Mon, 3 Mar 2014 11:00:47 + Simon Slavin wrote: > What the heck ? Is this a particular implementation of RAID or a > conceptual problem with how RAID is designed to work ? It sounds > like a bug in one particular model rather than a general problem with > how RAID

Re: [sqlite] Why would batched write operations NOT be faster than individual ones

Hi, Von: sqlite-users-boun...@sqlite.org [mailto:sqlite-users-boun...@sqlite.org] > On 3 Mar 2014, at 8:18am, Markus Schaber wrote: > > Another way to bust your data is to rely on RAID 5 or 6 or similar, at > > least if the software does not take special care. > > > > When

Re: [sqlite] Why would batched write operations NOT be faster than individual ones

On 3 Mar 2014, at 8:18am, Markus Schaber wrote: > Another way to bust your data is to rely on RAID 5 or 6 or similar, at least > if the software does not take special care. > > When those mechanisms, updating a block always results in at least 2 disk > writes: The data

Re: [sqlite] Why would batched write operations NOT be faster than individual ones

Hi, sqlite-users-boun...@sqlite.org [mailto:sqlite-users-boun...@sqlite.org] > On 3 Mar 2014, at 3:41am, romtek wrote: > [...] > > Here's a SQLite engineer writing about the same thing: section 3.1 of > > > > Your disk hardware,

Re: [sqlite] Why would batched write operations NOT be faster than individual ones

On 3 Mar 2014, at 3:41am, romtek wrote: > Thanks, Simon. Interestingly, for this server, disk operations aren't > particularly fast. One SQLite write op takes about 4 times longer than on a > HostGator server. That supports the idea that storage is simulated (or

Re: [sqlite] Why would batched write operations NOT be faster than individual ones

Thanks, Simon. Interestingly, for this server, disk operations aren't particularly fast. One SQLite write op takes about 4 times longer than on a HostGator server. I wonder if what I/you described also means that this file system isn't likely to support file locks needed for SQLite to control

Re: [sqlite] Why would batched write operations NOT be faster than individual ones

On 3 Mar 2014, at 2:14am, romtek wrote: > On one of my hosting servers (this one is a VPS), a bunch of write > operations take practically the same amount of time when they are performed > individually as when they are performed as one explicit transaction. I've > varied the

Re: [sqlite] Why would batched write operations NOT be faster than individual ones

In case this gives somebody a clue, the server in question is on http://vps.net/. On Sun, Mar 2, 2014 at 8:14 PM, romtek wrote: > Hi, > > On one of my hosting servers (this one is a VPS), a bunch of write > operations take practically the same amount of time when they are