Re: [sqlite] multiple writers for in-memory datastore
for those who may be interested: I ran a test with SQLite version: 3.5.8 I tried the scheme described earlier with each thread sharing a connection but writing into its own attached in-memory db on that connection. Didn't work. all but the first writer thread failed with a SQLITE_ERROR oh well. I think I will go with CoreData on MacOSX and figure out something else to do on Windows later. my thanks to all who attempted to provide a solution. -James ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] cidr data type
What stops you from building in the 128 bit address logic? Christof Meerwald wrote: > On Fri, 18 Apr 2008 15:59:14 -0600, Dennis Cote wrote: > >>Christof Meerwald wrote: >> >>>Currently, I am thinking of storing start and end IP addresses as a blob in >>>the database - that way I would be able to use the "between" operator in >>>selects, e.g. >>> select X'c0a81234' between X'c0a8' and X'c0a8'; > > [...] > >>I would store the IP addresses, network addresses, and subnet width as >>integers. Then create a few custom function to manipulate them. > > > Ok, that would work for IPv4 addresses, but if I ever wanted to use IPv6 > addresses, then I would have to go back to using blobs - as integers are > limited to 64 bits in SQLite. > > > Christof > ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] a suggestion to write tutorial for sqlite
I think one of the most lacking aspects of the documentation are examples. Perhaps this is better addressed in the proposed tutorial, but not all the "SQL Syntax" pages make it clear how to use the statement, especially the more complex ones like SELECT, and expressions. The datetime use is also not always easy to grasp (as witnessed by questions on this list). So, I think a tutorial is a great idea! ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] a suggestion to write tutorial for sqlite
D. Richard Hipp wrote: > On Apr 19, 2008, at 5:44 PM, Jay A. Kreibich wrote: > >> This is a bit off-topic for the mailing list, so please feel free >> to send stuff directly to the address below. >> >> > > It would be good, I think, to have a public record of this > conversation. We can create an [EMAIL PROTECTED] > mailing list if you think it would help. > > D. Richard Hipp > [EMAIL PROTECTED] > > I agree with DRH. I too would like to see a public record so that everyone can contribute and discuss. I see great value in a tutorial not just for myself (I'm no great database expert...yet!), but also for other members of my project team at my place of employment, and the students I try to introduce databases to. Also...I just recieved an Amazon Kindle reader. I am still learning how to use it but I'd like the page design of any tutorial to take in mind someone like me might pop it on an e-book reader like the Kindle. So far, Amazon seems to be having trouble converting pdf documents to Kindle format. The conversion process "mixes up" text on a short sample PDF document I'm testing with. It could be due to the way the PDF is designed (the author may have made mistakes during the conversion to PDF which got amplified by my subsequent conversion to Amazon Kindle format). Any errors that can be traced to Amazon's conversion software will probably get fixed fast, especially if the company open sources it. But anyhow folks, let's keep in mind that a tutorial should have a page design that is e-book friendly. Thanks Bob Cochran Greenbelt, Maryland, USA > > ___ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > > ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] a suggestion to write tutorial for sqlite
Why not include a section "User Contributed Notes" (in the style of the php doc) besides each page of the SQLite man pages? specially those devoted to: 1. List Of Objects 2. List Of Constants 3. List Of Functions HTH Adolfo. -Original Message- From: D. Richard Hipp [mailto:[EMAIL PROTECTED] Sent: Saturday, April 19, 2008 05:47 PM To: [EMAIL PROTECTED], 'General Discussion of SQLite Database' Subject: Re: [sqlite] a suggestion to write tutorial for sqlite On Apr 19, 2008, at 5:44 PM, Jay A. Kreibich wrote: >> This is a bit off-topic for the mailing list, so please feel free > to send stuff directly to the address below. >It would be good, I think, to have a public record of thisconversation. We can create an [EMAIL PROTECTED] list if you think it would help. D. Richard [EMAIL PROTECTED] ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] multiple writers for in-memory datastore
ok. I think I see what you are suggesting. You want to provide a mechanism to create memory files that SQLite thinks are disk filesthat way you could create multiple connections to them. an interesting idea. However, that may be more effort that I can justify at this point. I'll think about it. yes. I am fluent in STL. On Apr 19, 2008, at 1:19 PM, Virgilio Alexandre Fornazin wrote: > Imagine the following cenario (I assume you know c++ stdlib) > > A map of strings (filenames) to in-memory file handlers (the objects > that > will handle the shared memory or heap files). > > These files handlers will exists until the process exists and do not > receive > a delelefile() vfs call. > > File handlers can synchronize RW-Locks using internal mutex/criticat > sections/semaphores/spin locks, etc. > > When you create a new file in vfs, a new handler is created and > assigned to > that filename and registered in this map. > > > > > > > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of James Gregurich > Sent: sábado, 19 de abril de 2008 17:02 > To: General Discussion of SQLite Database > Subject: Re: [sqlite] multiple writers for in-memory datastore > > > I don't immediately see how that would solve the problem. > > The limitation of interest here (based on my perhaps limited > understanding) is that locking has file-level granularity. I don't > immediately see how a VST implementation would allow for changing the > locking granularity of the overall system. > > -James > > On Apr 19, 2008, at 12:03 PM, Virgilio Fornazin wrote: > >> what about creating a VFS for such task ? Can be accomplished in >> many ways, >> using heap memory, shared memory... not so easy to do, but not much >> complicated too... locking can be provided by multiple-readers >> single-writers locks strategies, etc... >> >> On Sat, Apr 19, 2008 at 2:29 PM, James Gregurich >> <[EMAIL PROTECTED]> >> wrote: >> >>> >>> oh good! That isn't the version that ships with Leopard, but I can >>> live with deploying my own version as part of my app. >>> >>> Will l get the writer parallelism I'm after as long as each thread >>> writes exclusively into its own attached db? >>> >>> >>> in other wordstwo bulk insert operations going on simultaneously >>> on the same connection but each insert operation going into a >>> different attached in-memory db. >>> >>> >>> On Apr 19, 2008, at 9:20 AM, Dan wrote: >>> On Apr 19, 2008, at 6:06 AM, James Gregurich wrote: > > I'll ask this question. The answer is probably "no," but I'll ask > it > for the sake of completeness. > > > Suppose I created an in-memory db. I use the attach command to > associate an additional in-memory db. Suppose I assign the main > db to > thread 1 and the associated db to thread 2. Can I share the > connection > across the 2 threads if each thread works exclusively in its own > db? > > I am aware that the connection is generally not threadsafe, but > will > it work if the two threads don't operate on the same db at the > same > time? As of 3.5, sqlite connections are threadsafe by default. With earlier versions, this trick will not work. Dan. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >>> >>> ___ >>> sqlite-users mailing list >>> sqlite-users@sqlite.org >>> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >>> >> ___ >> sqlite-users mailing list >> sqlite-users@sqlite.org >> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > ___ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > ___ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] a suggestion to write tutorial for sqlite
A few things that confused me in my (still ongoing) learning. 1. Bindings, in that the bind needed to be perfomed each and every time. 2. Transactions, the begin vs begin immediate. Coming from a database background I assumed the begin started the transaction but did not... 3. Locking, SQLITE_BUSY waiting. 4. Page size pragma having to use this prior to creating a table for it to be effective. 5. Prepare/bind/step/finalize/reset and when to use in success/error conditions. 6. Thread safety and threaded access. But this has been vastly improved in 3.5.x series! 7. Shared cache, appropriate uses? Just a start and my .02 Thanks, Ken "Jay A. Kreibich" <[EMAIL PROTECTED]> wrote: On Sat, Apr 19, 2008 at 05:40:45PM +0100, Toby Roworth scratched on the wall: > mikeobe wrote: > > i found it boring to learn how to use sqlite, maybe we can write a > > tutorial for it, with examples, it will be much easier for the > > beginner to start with sqlite. > > Agreed - I had to learn from the 5 minute introduction (which I was > later told was a poor way of doing it), and then by using the reference, > which leaves a lot to be desired when it comes to having little > knowledge of SQLite - and it's still giving me trouble now! What are we looking for? A 60 minute introduction? Any thoughts on specific topics, or is the main thing just covering the basics of the API in vanilla situations? I have a great deal of interest in this area, and would love to hear from anyone that has thoughts, ideas, or comments. I would especially like to hear if there is a specific area or concept that confused folks when they were learning SQLite. SQLite tends to get used by a lot of people that have a stronger background in software development than in databases, so I would expect there to be some confusion about "database things" like table design and complex query commands. Solid introductory materials need to take that into account, but we need to gather some more information on precisely what that difference means. This is a bit off-topic for the mailing list, so please feel free to send stuff directly to the address below. -j -- Jay A. Kreibich < J A Y @ K R E I B I.C H > "'People who live in bamboo houses should not throw pandas.' Jesus said that." - "The Ninja", www.AskANinja.com, "Special Delivery 10: Pop!Tech 2006" ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] a suggestion to write tutorial for sqlite
On Apr 19, 2008, at 5:44 PM, Jay A. Kreibich wrote: > > This is a bit off-topic for the mailing list, so please feel free > to send stuff directly to the address below. > It would be good, I think, to have a public record of this conversation. We can create an [EMAIL PROTECTED] mailing list if you think it would help. D. Richard Hipp [EMAIL PROTECTED] ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] a suggestion to write tutorial for sqlite
On Sat, Apr 19, 2008 at 05:40:45PM +0100, Toby Roworth scratched on the wall: > mikeobe wrote: > > i found it boring to learn how to use sqlite, maybe we can write a > > tutorial for it, with examples, it will be much easier for the > > beginner to start with sqlite. > > Agreed - I had to learn from the 5 minute introduction (which I was > later told was a poor way of doing it), and then by using the reference, > which leaves a lot to be desired when it comes to having little > knowledge of SQLite - and it's still giving me trouble now! What are we looking for? A 60 minute introduction? Any thoughts on specific topics, or is the main thing just covering the basics of the API in vanilla situations? I have a great deal of interest in this area, and would love to hear from anyone that has thoughts, ideas, or comments. I would especially like to hear if there is a specific area or concept that confused folks when they were learning SQLite. SQLite tends to get used by a lot of people that have a stronger background in software development than in databases, so I would expect there to be some confusion about "database things" like table design and complex query commands. Solid introductory materials need to take that into account, but we need to gather some more information on precisely what that difference means. This is a bit off-topic for the mailing list, so please feel free to send stuff directly to the address below. -j -- Jay A. Kreibich < J A Y @ K R E I B I.C H > "'People who live in bamboo houses should not throw pandas.' Jesus said that." - "The Ninja", www.AskANinja.com, "Special Delivery 10: Pop!Tech 2006" ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] multiple writers for in-memory datastore
Imagine the following cenario (I assume you know c++ stdlib) A map of strings (filenames) to in-memory file handlers (the objects that will handle the shared memory or heap files). These files handlers will exists until the process exists and do not receive a delelefile() vfs call. File handlers can synchronize RW-Locks using internal mutex/criticat sections/semaphores/spin locks, etc. When you create a new file in vfs, a new handler is created and assigned to that filename and registered in this map. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of James Gregurich Sent: sábado, 19 de abril de 2008 17:02 To: General Discussion of SQLite Database Subject: Re: [sqlite] multiple writers for in-memory datastore I don't immediately see how that would solve the problem. The limitation of interest here (based on my perhaps limited understanding) is that locking has file-level granularity. I don't immediately see how a VST implementation would allow for changing the locking granularity of the overall system. -James On Apr 19, 2008, at 12:03 PM, Virgilio Fornazin wrote: > what about creating a VFS for such task ? Can be accomplished in > many ways, > using heap memory, shared memory... not so easy to do, but not much > complicated too... locking can be provided by multiple-readers > single-writers locks strategies, etc... > > On Sat, Apr 19, 2008 at 2:29 PM, James Gregurich <[EMAIL PROTECTED]> > wrote: > >> >> oh good! That isn't the version that ships with Leopard, but I can >> live with deploying my own version as part of my app. >> >> Will l get the writer parallelism I'm after as long as each thread >> writes exclusively into its own attached db? >> >> >> in other wordstwo bulk insert operations going on simultaneously >> on the same connection but each insert operation going into a >> different attached in-memory db. >> >> >> On Apr 19, 2008, at 9:20 AM, Dan wrote: >> >>> >>> On Apr 19, 2008, at 6:06 AM, James Gregurich wrote: >>> I'll ask this question. The answer is probably "no," but I'll ask it for the sake of completeness. Suppose I created an in-memory db. I use the attach command to associate an additional in-memory db. Suppose I assign the main db to thread 1 and the associated db to thread 2. Can I share the connection across the 2 threads if each thread works exclusively in its own db? I am aware that the connection is generally not threadsafe, but will it work if the two threads don't operate on the same db at the same time? >>> >>> As of 3.5, sqlite connections are threadsafe by default. With >>> earlier versions, this trick will not work. >>> >>> Dan. >>> >>> >>> ___ >>> sqlite-users mailing list >>> sqlite-users@sqlite.org >>> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >> >> ___ >> sqlite-users mailing list >> sqlite-users@sqlite.org >> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >> > ___ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] multiple writers for in-memory datastore
I don't immediately see how that would solve the problem. The limitation of interest here (based on my perhaps limited understanding) is that locking has file-level granularity. I don't immediately see how a VST implementation would allow for changing the locking granularity of the overall system. -James On Apr 19, 2008, at 12:03 PM, Virgilio Fornazin wrote: > what about creating a VFS for such task ? Can be accomplished in > many ways, > using heap memory, shared memory... not so easy to do, but not much > complicated too... locking can be provided by multiple-readers > single-writers locks strategies, etc... > > On Sat, Apr 19, 2008 at 2:29 PM, James Gregurich <[EMAIL PROTECTED]> > wrote: > >> >> oh good! That isn't the version that ships with Leopard, but I can >> live with deploying my own version as part of my app. >> >> Will l get the writer parallelism I'm after as long as each thread >> writes exclusively into its own attached db? >> >> >> in other wordstwo bulk insert operations going on simultaneously >> on the same connection but each insert operation going into a >> different attached in-memory db. >> >> >> On Apr 19, 2008, at 9:20 AM, Dan wrote: >> >>> >>> On Apr 19, 2008, at 6:06 AM, James Gregurich wrote: >>> I'll ask this question. The answer is probably "no," but I'll ask it for the sake of completeness. Suppose I created an in-memory db. I use the attach command to associate an additional in-memory db. Suppose I assign the main db to thread 1 and the associated db to thread 2. Can I share the connection across the 2 threads if each thread works exclusively in its own db? I am aware that the connection is generally not threadsafe, but will it work if the two threads don't operate on the same db at the same time? >>> >>> As of 3.5, sqlite connections are threadsafe by default. With >>> earlier versions, this trick will not work. >>> >>> Dan. >>> >>> >>> ___ >>> sqlite-users mailing list >>> sqlite-users@sqlite.org >>> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >> >> ___ >> sqlite-users mailing list >> sqlite-users@sqlite.org >> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >> > ___ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] multiple writers for in-memory datastore
what about creating a VFS for such task ? Can be accomplished in many ways, using heap memory, shared memory... not so easy to do, but not much complicated too... locking can be provided by multiple-readers single-writers locks strategies, etc... On Sat, Apr 19, 2008 at 2:29 PM, James Gregurich <[EMAIL PROTECTED]> wrote: > > oh good! That isn't the version that ships with Leopard, but I can > live with deploying my own version as part of my app. > > Will l get the writer parallelism I'm after as long as each thread > writes exclusively into its own attached db? > > > in other wordstwo bulk insert operations going on simultaneously > on the same connection but each insert operation going into a > different attached in-memory db. > > > On Apr 19, 2008, at 9:20 AM, Dan wrote: > > > > > On Apr 19, 2008, at 6:06 AM, James Gregurich wrote: > > > >> > >> I'll ask this question. The answer is probably "no," but I'll ask it > >> for the sake of completeness. > >> > >> > >> Suppose I created an in-memory db. I use the attach command to > >> associate an additional in-memory db. Suppose I assign the main db to > >> thread 1 and the associated db to thread 2. Can I share the > >> connection > >> across the 2 threads if each thread works exclusively in its own db? > >> > >> I am aware that the connection is generally not threadsafe, but will > >> it work if the two threads don't operate on the same db at the same > >> time? > > > > As of 3.5, sqlite connections are threadsafe by default. With > > earlier versions, this trick will not work. > > > > Dan. > > > > > > ___ > > sqlite-users mailing list > > sqlite-users@sqlite.org > > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > ___ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] multiple writers for in-memory datastore
oh good! That isn't the version that ships with Leopard, but I can live with deploying my own version as part of my app. Will l get the writer parallelism I'm after as long as each thread writes exclusively into its own attached db? in other wordstwo bulk insert operations going on simultaneously on the same connection but each insert operation going into a different attached in-memory db. On Apr 19, 2008, at 9:20 AM, Dan wrote: > > On Apr 19, 2008, at 6:06 AM, James Gregurich wrote: > >> >> I'll ask this question. The answer is probably "no," but I'll ask it >> for the sake of completeness. >> >> >> Suppose I created an in-memory db. I use the attach command to >> associate an additional in-memory db. Suppose I assign the main db to >> thread 1 and the associated db to thread 2. Can I share the >> connection >> across the 2 threads if each thread works exclusively in its own db? >> >> I am aware that the connection is generally not threadsafe, but will >> it work if the two threads don't operate on the same db at the same >> time? > > As of 3.5, sqlite connections are threadsafe by default. With > earlier versions, this trick will not work. > > Dan. > > > ___ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] a suggestion to write tutorial for sqlite
Agreed - I had to learn from the 5 minute introduction (which I was later told was a poor way of doing it), and then by using the reference, which leaves a lot to be desired when it comes to having little knowledge of SQLite - and it's still giving me trouble now! Toby mikeobe wrote: > i found it boring to learn how to use sqlite, maybe we can write a tutorial > for it, with examples, > it will be much easier for the beginner to start with sqlite. > > 2008-04-19 > mikeobe > > > ___ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > > > -- Sent by Toby Roworth ([EMAIL PROTECTED]) This message is intended for the named reciepients only, and should not be forwarded without permission The conents of this message may be ©Toby Roworth ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
[sqlite] a suggestion to write tutorial for sqlite
i found it boring to learn how to use sqlite, maybe we can write a tutorial for it, with examples, it will be much easier for the beginner to start with sqlite. 2008-04-19 mikeobe ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] multiple writers for in-memory datastore
On Apr 19, 2008, at 6:06 AM, James Gregurich wrote: > > I'll ask this question. The answer is probably "no," but I'll ask it > for the sake of completeness. > > > Suppose I created an in-memory db. I use the attach command to > associate an additional in-memory db. Suppose I assign the main db to > thread 1 and the associated db to thread 2. Can I share the connection > across the 2 threads if each thread works exclusively in its own db? > > I am aware that the connection is generally not threadsafe, but will > it work if the two threads don't operate on the same db at the same > time? As of 3.5, sqlite connections are threadsafe by default. With earlier versions, this trick will not work. Dan. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] cidr data type
On Fri, Apr 18, 2008 at 08:59:17PM -0500, John Stanton wrote: > Use a function and convert the IP address from dotted format to a 32 bit > unsigned integer. You can AND and OR these to establish inclusion and > exclusion. That doesn't get you the prefix length. If you represent the mask/prefix length as a separate value then you have to be careful when sorting. If you represent prefixes as bit strings then you lose that problem, but without a way to cast them to integers you have to add user-defined functions to do bit-wise operations on them -- or at least functions to convert to/from integert (but that only works well for IPv4). BTW, this can be very useful when one stores data on networks and aggregations, such as when building a model of routing, or a database of network and aggregate allocations. It then becomes important to be able to determine whether one prefix is inside the other -- that's almost the most important operation -- and to be able to query for prefixes that fit inside another, ... Nico -- ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
[sqlite] how to build sqlite under winxp?
NO make file found in that zip, downloaded from the official website... 2008-04-19 mikeobe ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Question about using sqlite database located on shared folder
> server machine actually per request from cient. Now if, for some reason, > connection with machine taht started writing table goes awol. That > client finished his job or is just dead but server still thinks > connection is needed and keeps file locked hence preventing any other > client to do reading/writing. Though I haven't tested it, I would hope that the O/S would detect that the client disconnected, and would release any file lock(s) held. Seems like it would be easy enough to test: On a couple of machines, start a couple of SQLite command shells to the shared Db. On the first, start a BEGIN IMMEDIATE;, then yank the ethernet plug. See if the OS eventually releases the lock, such that the second client can get access. I'm sure others have more experience with this. But it seems like it would be easy enough to test. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] fetching and updating
"Mike Johnston" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] > I'm in a loop processing the result set using sqlite3_step. I need to > insert/update the same sqlite database but a different table. I > can't get the write lock while I have this active statement I'm using > sqlite3_step to move through. With a recent enough SQLite version, you can run modification statements while a select statement is in progress. You have to do it on the same connection. Igor Tandetnik ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
[sqlite] Question about using sqlite database located on shared folder
I received a task to investigate feasibility of using sqlite database located on a server in an internal windows network. I know this is not most recommended scenario but I still have to do investigation. Let us assume this case: 2 machines are accessing sqlite database located on a third machine in shared folder with full read/write permissions. At some point in time both machines want to access database for writing some data in teh same table. One machine request comes first and table is locked. Therefore the other machine receives error, or goes to wait timeout period before trying again. Locking and releasing is done by server machine actually per request from cient. Now if, for some reason, connection with machine taht started writing table goes awol. That client finished his job or is just dead but server still thinks connection is needed and keeps file locked hence preventing any other client to do reading/writing. Is there a way to detect this situation and what would be the remedy? Please do not respond me with use client/server database. This investigation is only related to sqlite usage. Thanks in advance, Darko Miletic ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] no VFS error
Thanks - that seems to have fixed it
D. Richard Hipp wrote:
> On Apr 19, 2008, at 9:19 AM, Toby Roworth wrote:
>
>>> What value are you passing as the 4th argument to
>>> sqlite3_open_v2()? (I assume you are using sqlite3_open_v2()
>>> since that seems the mostly likely way to get this error.)
>>>
>>>
>> I'm passing a blank string - this would appear to be the problem!
>> errorCode = sqlite3_open_v2("data/texts.db", &dataBase,
>> SQLITE_OPEN_READONLY, "");
>>
>>
>
> A null pointer (aka zero). 0. Very different from an
> empty string.
>
> D. Richard Hipp
> [EMAIL PROTECTED]
>
>
>
> ___
> sqlite-users mailing list
> sqlite-users@sqlite.org
> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
>
>
>
--
Sent by Toby Roworth ([EMAIL PROTECTED])
This message is intended for the named reciepients only, and should not
be forwarded without permission
The conents of this message may be ©Toby Roworth
___
sqlite-users mailing list
sqlite-users@sqlite.org
http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] no VFS error
On Apr 19, 2008, at 9:19 AM, Toby Roworth wrote:
>>
>> What value are you passing as the 4th argument to
>> sqlite3_open_v2()? (I assume you are using sqlite3_open_v2()
>> since that seems the mostly likely way to get this error.)
>>
> I'm passing a blank string - this would appear to be the problem!
> errorCode = sqlite3_open_v2("data/texts.db", &dataBase,
> SQLITE_OPEN_READONLY, "");
>
A null pointer (aka zero). 0. Very different from an
empty string.
D. Richard Hipp
[EMAIL PROTECTED]
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Re: [sqlite] no VFS error
D. Richard Hipp wrote:
> On Apr 19, 2008, at 7:41 AM, Toby Roworth wrote:
>
>
>> When attempting to open a database, I am getting a "no such vfs"
>> error.
>>
>> What is likely to be causing this - a quick search suggested that vfs
>> may stand for virtual file system - is this right?
>>
>> Any help would be appreciated
>>
>>
>
>
> What value are you passing as the 4th argument to
> sqlite3_open_v2()? (I assume you are using sqlite3_open_v2()
> since that seems the mostly likely way to get this error.)
>
I'm passing a blank string - this would appear to be the problem!
errorCode = sqlite3_open_v2("data/texts.db", &dataBase,
SQLITE_OPEN_READONLY, "");
What shoudl I be passing (on a windows system)
Thanks
> D. Richard Hipp
> [EMAIL PROTECTED]
>
>
>
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>
--
Sent by Toby Roworth ([EMAIL PROTECTED])
This message is intended for the named reciepients only, and should not
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Re: [sqlite] EXISTS operator doesn't seem to work
On Apr 19, 2008, at 7:06 AM, pinco palletto wrote: > update register > set note = (select ORT.note from old_register ORT > where ORT.person_id = person_id and ORT.document_id = document_id) > where exists ( > select ORT.* from old_register ORT > where ORT.person_id = person_id and ORT.document_id = document_id); update register set note = (select ORT.note from old_register ORT where ORT.person_id = register.person_id and ORT.document_id = register.document_id) where exists (select ORT.* from old_register ORT where ORT.person_id = register.person_id and ORT.document_id = register. document_id); D. Richard Hipp [EMAIL PROTECTED] ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] no VFS error
On Apr 19, 2008, at 7:41 AM, Toby Roworth wrote: > When attempting to open a database, I am getting a "no such vfs" > error. > > What is likely to be causing this - a quick search suggested that vfs > may stand for virtual file system - is this right? > > Any help would be appreciated > What value are you passing as the 4th argument to sqlite3_open_v2()? (I assume you are using sqlite3_open_v2() since that seems the mostly likely way to get this error.) D. Richard Hipp [EMAIL PROTECTED] ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
[sqlite] no VFS error
When attempting to open a database, I am getting a "no such vfs" error. What is likely to be causing this - a quick search suggested that vfs may stand for virtual file system - is this right? Any help would be appreciated Toby Roworth -- Sent by Toby Roworth ([EMAIL PROTECTED]) This message is intended for the named reciepients only, and should not be forwarded without permission The conents of this message may be ©Toby Roworth ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
[sqlite] EXISTS operator doesn't seem to work
Hi everybody, I have to update a 'note' field of a 'register' table with the values from the correspective entries of an 'old_register' table. The 'old_register' table is shorter than 'register', I mean it has less records, but every primary key's value in 'old_register' is also the value of one record of 'register'. In other words, if I just could succeed in the update, the resulting 'register' table's record set would be a superset of the 'old_register' 's one. BTW in both tables the tuple (person_id, document_id) is the primary key. Here's the query: update register set note = (select ORT.note from old_register ORT where ORT.person_id = person_id and ORT.document_id = document_id) where exists ( select ORT.* from old_register ORT where ORT.person_id = person_id and ORT.document_id = document_id); Well, it just keeps updating the 'note' field of ALL the records of 'register' with the 'note' field's value of the first record of 'old_register'. Weird, isn't it? And most of all, the following query works, I mean it correctly returns the only records of 'register' which have a correspondant record in 'old_register' whith the same values for the (primary) key (person_id, document_id)! select RT.person_id, RT.document_id, RT.note from register RT where exists ( select ORT.* from old_register ORT where ORT.person_id = RT.person_id and ORT.document_id = RT.document_id) One might think that it is a problem of full qualification of the field names, but if you try to fully qualify the person_id and document_id in the 'update' query, sqlite raises an error. It drives me mad, please help! Thanks, C. _ Racconta le tue emozioni sul blog! http://home.services.spaces.live.com/ ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] logging statements executed by the db
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 P Kishor wrote: > I have a rather opaque application that is calling my db. Is there > something I can turn on in SQLite that will log all the statements > executed against it? If you are using Linux then you can use the ltrace program to trace calls and their parameters. You would want to track execution of sqlite3_prepare. http://linux.die.net/man/1/ltrace Roger -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.6 (GNU/Linux) iD8DBQFICc9vmOOfHg372QQRAiX6AKCxaMN8kzLVGmSYagQIcdrjeV544gCgtUhR M51O8+VbS4RR43Ussb8a1UM= =jiLg -END PGP SIGNATURE- ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] cidr data type
On Fri, 18 Apr 2008 15:59:14 -0600, Dennis Cote wrote: > Christof Meerwald wrote: >> Currently, I am thinking of storing start and end IP addresses as a blob in >> the database - that way I would be able to use the "between" operator in >> selects, e.g. >> select X'c0a81234' between X'c0a8' and X'c0a8'; [...] > I would store the IP addresses, network addresses, and subnet width as > integers. Then create a few custom function to manipulate them. Ok, that would work for IPv4 addresses, but if I ever wanted to use IPv6 addresses, then I would have to go back to using blobs - as integers are limited to 64 bits in SQLite. Christof -- http://cmeerw.org sip:cmeerw at cmeerw.org mailto:cmeerw at cmeerw.org xmpp:cmeerw at cmeerw.org ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
