Re: [sqlite] Concurrency, MVCC

2004-04-16 Thread Christian Smith
On Thu, 15 Apr 2004, Doug Currie wrote: > >Thursday, April 15, 2004, 9:16:01 AM, Christian Smith wrote: > >> On Wed, 14 Apr 2004, Doug Currie wrote: > >>>One way to get table level locking without a great deal of pain is to >>>integrate the shadow paging ideas with BTree management. Rather than

Re: [sqlite] Concurrency, MVCC

2004-04-15 Thread Mark D. Anderson
On Thu, 15 Apr 2004 20:16:32 -0400, "Doug Currie" <[EMAIL PROTECTED]> said: > I used this design in a proprietary database in the late 1980s. The > only reason I didn't consider modifying SQLite this way up until now > is that I was anticipating BTree changes for 3.0, so I confined my > efforts

Re: [sqlite] Concurrency, MVCC

2004-04-15 Thread Doug Currie
Thursday, April 15, 2004, 9:16:01 AM, Christian Smith wrote: > On Wed, 14 Apr 2004, Doug Currie wrote: >>One way to get table level locking without a great deal of pain is to >>integrate the shadow paging ideas with BTree management. Rather than >>using page tables for the shadow pages, use the

Re: [sqlite] Concurrency, MVCC

2004-04-15 Thread Christian Smith
On Thu, 15 Apr 2004, Andrew Piskorski wrote: >On Thu, Apr 15, 2004 at 02:16:01PM +0100, Christian Smith wrote: >> Right tool for the job. Multiple writers has client/server database >> written all over it. KISS. > >No, not true, at least not when the multiple writers are all threads >within one

Re: [sqlite] Concurrency, MVCC

2004-04-15 Thread Andrew Piskorski
On Thu, Apr 15, 2004 at 02:16:01PM +0100, Christian Smith wrote: > Right tool for the job. Multiple writers has client/server database > written all over it. KISS. No, not true, at least not when the multiple writers are all threads within one single process, which appears to be the common case

Re: [sqlite] Concurrency, MVCC

2004-04-15 Thread Christian Smith
On Wed, 14 Apr 2004, Doug Currie wrote: >Wednesday, April 14, 2004, 1:16:54 AM, Andrew Piskorski wrote: > >> How could this be extended to support table locking and PostgreSQL's >> default "read committed" isolation level? Would the smallest locking >> granularity possible in Currie's design be

Re: [sqlite] Concurrency, MVCC

2004-04-15 Thread Mark D. Anderson
On Wed, 14 Apr 2004 08:13:39 -0400, "D. Richard Hipp" <[EMAIL PROTECTED]> said: >* Support for atomic commits of multi-database transactions, > which gives you a limited kind of table-level locking, > assuming you are willing to put each table in a separate > database. and

Re: [sqlite] Concurrency, MVCC

2004-04-14 Thread Mark D. Anderson
Wednesday, April 14, 2004, 1:16:54 AM, Andrew Piskorski wrote: > as far as I can tell, it seems to be describing a system with > the usual Oracle/PostgreSQL MVCC semantics, EXCEPT of course that > Currie proposes that each Write transaction must take a lock on the > database as a whole. Well, i

Re: [sqlite] Concurrency, MVCC

2004-04-14 Thread Doug Currie
> D. Richard Hipp wrote: >> >> My thoughts on BlueSky have been added to the wiki page: >>http://www.sqlite.org/cvstrac/wiki?p=BlueSky I added some responses; I do not agree with Richard's concerns about Shadow Paging, and I corrected some mistaken conclusions. I apologize if my paper was

Re: [sqlite] Concurrency, MVCC

2004-04-14 Thread D. Richard Hipp
D. Richard Hipp wrote: My thoughts on BlueSky have been added to the wiki page: http://www.sqlite.org/wiki?p=BlueSky That URL should have been: http://www.sqlite.org/cvstrac/wiki?p=BlueSky Left out the "cvstrac". Sorry for the confusion. -- D. Richard Hipp -- [EMAIL PROTECTED] --

Re: [sqlite] Concurrency, MVCC

2004-04-14 Thread D. Richard Hipp
Andrew Piskorski wrote: How feasible would it be to add support for higher concurrency to SQLite, especially via MVCC? My thoughts on BlueSky have been added to the wiki page: http://www.sqlite.org/wiki?p=BlueSky The current plan for version 3.0 is as follows: * Support for a modification