[sqlite] WAL mode and backup API
Hello, if a running sqlite database is in WAL mode and a backup is performed on that db using the sqlite3_backup API, does that process is considered like a reader and can proceed concurrently with other readers and with the other writer? Thanks a lot for your answer. -- Marco Bambini http://www.sqlabs.com ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] WAL mode and backup API
On 11/30/2010 05:03 PM, Marco Bambini wrote: Hello, if a running sqlite database is in WAL mode and a backup is performed on that db using the sqlite3_backup API, does that process is considered like a reader and can proceed concurrently with other readers and with the other writer? Yes. The connection to the backup source acts like any other reader. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] WAL mode and backup API
On 30.11.2010 11:32, Dan Kennedy wrote: On 11/30/2010 05:03 PM, Marco Bambini wrote: Hello, if a running sqlite database is in WAL mode and a backup is performed on that db using the sqlite3_backup API, does that process is considered like a reader and can proceed concurrently with other readers and with the other writer? Yes. The connection to the backup source acts like any other reader. BTW: Is there any chance that in the future the wal mode will avoid that the backup API will restart on DB changes during the backup loop ? Currently, even in wal mode, it does restart when changes are detected while the backup is ongoing. Marcus ___ 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] Question
As said off topic - but I have never heard of a cell ID being recorded with an SMS message. You can find more info on the SMS message format by search for sms pdu (protocol description unit) you can see from this somewhat complex structure that the cell ID is not part of the transmitted message format. This information is available at the handset though and it is *possible* that it is recorded on specific handsets although I have never seen it. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] WAL mode and backup API
BTW: Is there any chance that in the future the wal mode will avoid that the backup API will restart on DB changes during the backup loop ? Currently, even in wal mode, it does restart when changes are detected while the backup is ongoing. What happens if you open a read transaction on the source database before starting the backup? i.e. sqlite3_exec(pSource, BEGIN; SELECT * FROM sqlite_master, 0, 0, 0); ... do backup ... sqlite3_exec(pSource, COMMIT, 0, 0, 0); Does that help things any? ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] WAL mode and backup API
On 30.11.2010 11:50, Dan Kennedy wrote: BTW: Is there any chance that in the future the wal mode will avoid that the backup API will restart on DB changes during the backup loop ? Currently, even in wal mode, it does restart when changes are detected while the backup is ongoing. What happens if you open a read transaction on the source database before starting the backup? i.e. sqlite3_exec(pSource, BEGIN; SELECT * FROM sqlite_master, 0, 0, 0); ... do backup ... sqlite3_exec(pSource, COMMIT, 0, 0, 0); Does that help things any? wow... what a trick! Using your hint I'm not able to reproduce any restarts! I can imagine what your hint does in wal mode, but without your input I would never came to that idea... :-) Thanks Dan! This makes the wal mode and backup API even more sexy. Marcus ___ 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] searching with like on FTS3
Hi recently I noticed that i can't search with the like '%searchword%' syntax on an FTS3 virtual table. And with match i can't search on example sentences (the indexed data is a japanese dictionary an therefore has no spaces in example sentences and there is no perfekt tokenizer atm i tried mecab but it makes misstakes). Is there no other way than to hold the same data in an virtual FTS3 and a normal table to do both search types? because i don't want to bloat the download and in memory caching. the normal table is 29MB indexed is 59MB (and loaded completely in memory ~80MB) both together would be over 100MB when loading completely into memory and with basically the same data twice. regards boscowitch ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
[sqlite] cost of sqlite3_open
Hi, I'm working on a multi-threaded image server and I have 2 questions: 1) How expensive is a call to sqlite3_open. Does a call to sqlite3_enable_shared_cache make it cheaper? 2) If sqlite3_open is an expensive operation then I would like to keep a list (cache) of open database connections (sqlite*'s). Here's how it *should* work: The main thread calls sqlite3_open a couple of times and pushes the resulting sqlite-handles into a concurrent queue. The worker thread then pops the handle from the queue, does what needs to be done and pushes the handle back. No sqlite-handle is used by more than one thread at the same time. Is that safe? Cheers, Christoph ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] cost of sqlite3_open
1) How expensive is a call to sqlite3_open. Does a call to sqlite3_enable_shared_cache make it cheaper? Its cost depends on the size of your schema as it gets parsed during open. Shared cache doesn't make it cheaper. It can make somewhat cheaper (in some cases) to use several connections to the same database with the cost of mutual exclusion of sqlite3_step calls working with any handle to the same database. But that's it. 2) If sqlite3_open is an expensive operation then I would like to keep a list (cache) of open database connections (sqlite*'s). Here's how it *should* work: The main thread calls sqlite3_open a couple of times and pushes the resulting sqlite-handles into a concurrent queue. The worker thread then pops the handle from the queue, does what needs to be done and pushes the handle back. No sqlite-handle is used by more than one thread at the same time. Is that safe? Yes, that's perfectly safe. Pavel On Tue, Nov 30, 2010 at 9:37 AM, Christoph Schreiber luky0...@yahoo.de wrote: Hi, I'm working on a multi-threaded image server and I have 2 questions: 1) How expensive is a call to sqlite3_open. Does a call to sqlite3_enable_shared_cache make it cheaper? 2) If sqlite3_open is an expensive operation then I would like to keep a list (cache) of open database connections (sqlite*'s). Here's how it *should* work: The main thread calls sqlite3_open a couple of times and pushes the resulting sqlite-handles into a concurrent queue. The worker thread then pops the handle from the queue, does what needs to be done and pushes the handle back. No sqlite-handle is used by more than one thread at the same time. Is that safe? Cheers, Christoph ___ 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] SQLITE transactions failing with multiple threads
Hello, I have 2 threads in my program, 1st thread is doing inserts into a table and 2nd thread is trying to update the already inserted columns. 1. I have bundled the 1000 inserts per transaction in 1st thread. 2. When I try to start a transaction in the 2nd thread for my updates (when the 1st thread is running simultaneously) I am getting an error(error code 1 - SQL error or missing database). If I start the begin transaction in 2nd thread after the 1st thread finishes it works normally. Is this normal behavior? Also not that both threads are using the same handle passed by main. -- View this message in context: http://old.nabble.com/SQLITE-transactions-failing-with-multiple-threads-tp30340806p30340806.html Sent from the SQLite mailing list archive at Nabble.com. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] SQLITE transactions failing with multiple threads
Quoth cricketfan srtedul...@yahoo.co.in, on 2010-11-30 07:49:36 -0800: Also not that both threads are using the same handle passed by main. No, don't do that. Using the same handle in two threads concurrently can break depending on the SQLite threading mode, and will gain you no parallelism in the modes where it works. Aside from that, transaction state is bound to a handle; you're starting a transaction and then trying to start another one inside it. Open two handles instead. --- Drake Wilson ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] SQLITE transactions failing with multiple threads
On 30 Nov 2010, at 3:49pm, cricketfan wrote: I have 2 threads in my program, 1st thread is doing inserts into a table and 2nd thread is trying to update the already inserted columns. 1. I have bundled the 1000 inserts per transaction in 1st thread. 2. When I try to start a transaction in the 2nd thread for my updates (when the 1st thread is running simultaneously) I am getting an error(error code 1 - SQL error or missing database). If I start the begin transaction in 2nd thread after the 1st thread finishes it works normally. Is this normal behavior? Also not that both threads are using the same handle passed by main. I think you identified the problem. Try having separate handles for each thread. Either have each thread open its own connection or have your main thread open two connections, one for the INSERTs, one for the UPDATEs. Simon. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Just compiled SQLite in Visual Studio
Thanks Igor. -Original Message- From: sqlite-users-boun...@sqlite.org [mailto:sqlite-users-boun...@sqlite.org] On Behalf Of Igor Tandetnik Sent: Monday, November 29, 2010 7:11 PM To: sqlite-users@sqlite.org Subject: Re: [sqlite] Just compiled SQLite in Visual Studio john darnell john.darn...@walsworth.com wrote: I just added it to a Visual Studio 8 project, turned off the use of precompiled headers (the project is a C++ project) and compiled the SQLite.c file without any errors. There is no such thing as a C++ project. A project in Visual Studio can happily contain both C and C++ files. By default, file extension determines whether the file is compiled with C or C++ compiler (.c would indicate C), and this could also be overridden in project settings on a per-file basis. -- Igor Tandetnik ___ 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] EXPLAIN QUERY PLAN
I've just discovered EXPLAIN QUERY PLAN; it looks quite useful, but one part of the output is somewhat opaque. The command returns three columns: order, from, and detail. order is evidently the order in which the indices are applied; the detail explains which table and index is involved. But what does the from column mean? Thanks! Will -- Will Duquette -- william.h.duque...@jpl.nasa.gov Athena Development Lead -- Jet Propulsion Laboratory It's amazing what you can do with the right tools. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
[sqlite] Creating a database.
I know this is a fundamental question, but in the book I'm using to learn SQLite, there is no reference that I can find for what one needs to do to create a database. I thought that simply using a CREATE statement with a database name included might do the trick, but alas it does not. I went to the SQLite website and under the SQLite in 5 minutes page it says to simply do this (after downloading the appropriate files, which I did) at the dos prompt: SQLite3 test.db When I tried it, I received this back: SQLite version 3.7.3 Enter .help for instructions Enter SQL statements terminated with a ; sqlite I quit out of the SQLite shell and looked for test.db and did not find it. So my question remains. How do I create a database? R, John A.M. Darnell Senior Programmer Walsworth Publishing Company Brookfield, MO John may also be reached at johnamdarn...@gmail.commailto:johnamdarn...@gmail.com Trivia SF question: In the movie, THE MATRIX, just before Neo and Trinity take a harrowing ride up an elevator shaft holding on to an elevator cable, Neo mutters a single phrase. What is that phrase? ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Creating a database.
On Tue, Nov 30, 2010 at 10:40:52AM -0600, john darnell scratched on the wall: I know this is a fundamental question, but in the book I'm using to learn SQLite, there is no reference that I can find for what one needs to do to create a database. I thought that simply using a CREATE statement with a database name included might do the trick, but alas it does not. From code, you use sqlite3_open_v2( ). See the docs for specifics: http://sqlite.org/c3ref/open.html From the shell, you just access a non-existent file. I went to the SQLite website and under the SQLite in 5 minutes page it says to simply do this (after downloading the appropriate files, which I did) at the dos prompt: SQLite3 test.db When I tried it, I received this back: SQLite version 3.7.3 Enter .help for instructions Enter SQL statements terminated with a ; sqlite I quit out of the SQLite shell and looked for test.db and did not find it. So my question remains. How do I create a database? The SQLite library uses lazy file creation. There are a number of configuration parameters that become fixed once the database header is written to disk. As such, the actual file creation is delayed until it *must* be written. This gives you a chance to issue PRAGMA commands and setup the proper configuration after the database is open, but before the header is written. To force SQLite to actually write the database file to disk just issue a CREATE TABLE statement: CREATE TABLE t ( i ); -j -- Jay A. Kreibich J A Y @ K R E I B I.C H Intelligence is like underwear: it is important that you have it, but showing it to the wrong people has the tendency to make them feel uncomfortable. -- Angela Johnson ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
[sqlite] creating a database
Okay, I seem to have figured it out. One needs to create the database and then add a table before the database will be created. Sorry for the baby steps. R, John A.M. Darnell Senior Programmer Walsworth Publishing Company Brookfield, MO John may also be reached at johnamdarn...@gmail.commailto:johnamdarn...@gmail.com Trivia SF question: In the movie, THE MATRIX, just before Neo and Trinity take a harrowing ride up an elevator shaft holding on to an elevator cable, Neo mutters a single phrase. What is that phrase? ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] EXPLAIN QUERY PLAN
On 11/30/2010 11:38 PM, Duquette, William H (316H) wrote: I've just discovered EXPLAIN QUERY PLAN; it looks quite useful, but one part of the output is somewhat opaque. The command returns three columns: order, from, and detail. order is evidently the order in which the indices are applied; the detail explains which table and index is involved. But what does the from column mean? Thanks! The output of EQP is changing for 3.7.4. But the interpretation of the from column remains the same. See here: http://www.sqlite.org/draft/eqp.html Buried about 2/3 of the way through section 1.1. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] EXPLAIN QUERY PLAN
Thanks, Dan! On 11/30/10 9:05 AM, Dan Kennedy danielk1...@gmail.com wrote: On 11/30/2010 11:38 PM, Duquette, William H (316H) wrote: I've just discovered EXPLAIN QUERY PLAN; it looks quite useful, but one part of the output is somewhat opaque. The command returns three columns: order, from, and detail. order is evidently the order in which the indices are applied; the detail explains which table and index is involved. But what does the from column mean? Thanks! The output of EQP is changing for 3.7.4. But the interpretation of the from column remains the same. See here: http://www.sqlite.org/draft/eqp.html Buried about 2/3 of the way through section 1.1. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users -- Will Duquette -- william.h.duque...@jpl.nasa.gov Athena Development Lead -- Jet Propulsion Laboratory It's amazing what you can do with the right tools. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] cost of sqlite3_open
Pavel, 1) How expensive is a call to sqlite3_open. Does a call to sqlite3_enable_shared_cache make it cheaper? Its cost depends on the size of your schema as it gets parsed during open. Isn't this contradictory with an answer by Igor made in a recent thread? Subject: Re: [sqlite] sqlite3_open on non-DB files / corrupt DBs Nick Shaw nick.s...@citysync.co.uk wrote: Is there a reason that sqlite3_open() will happily open a non-sqlite file, returning SQLITE_OK, instead of returning SQLITE_NOTADB, which would seem a more obvious return value? SQLite doesn't actually touch the file until the first substantive statement is executed on the connection. This allows one to set various PRAGMAs that can only be set before the database is created. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] cost of sqlite3_open
1) How expensive is a call to sqlite3_open. Does a call to sqlite3_enable_shared_cache make it cheaper? Its cost depends on the size of your schema as it gets parsed during open. Isn't this contradictory with an answer by Igor made in a recent thread? It's not contradictory. I say that real cost of sqlite3_open is parsing the schema. Igor says that this cost is actually deferred from inside sqlite3_open call to the first substantive sqlite3_step call. So you will have to pay this price anyway, just profiler output would be somewhat confusing. Pavel On Tue, Nov 30, 2010 at 1:50 PM, Jean-Christophe Deschamps j...@q-e-d.org wrote: Pavel, 1) How expensive is a call to sqlite3_open. Does a call to sqlite3_enable_shared_cache make it cheaper? Its cost depends on the size of your schema as it gets parsed during open. Isn't this contradictory with an answer by Igor made in a recent thread? Subject: Re: [sqlite] sqlite3_open on non-DB files / corrupt DBs Nick Shaw nick.s...@citysync.co.uk wrote: Is there a reason that sqlite3_open() will happily open a non-sqlite file, returning SQLITE_OK, instead of returning SQLITE_NOTADB, which would seem a more obvious return value? SQLite doesn't actually touch the file until the first substantive statement is executed on the connection. This allows one to set various PRAGMAs that can only be set before the database is created. ___ 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] searching with like on FTS3
On Mon, Nov 29, 2010 at 9:08 AM, Pascal Schnurr pasc...@boscowitch.de wrote: Hi recently I noticed that i can't search with the like '%searchword%' syntax on an FTS3 virtual table. I'm no expert, but are you sure? This exact example, using LIKE, appears in the FTS3 docs: http://www.sqlite.org/fts3.html#section_1 ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] searching with like on FTS3
It does but as you can see the like is only performed on a normal table and the match you find only entrys like sql or maby selserver but not blablalbasqlstatic Am Dienstag, den 30.11.2010, 11:50 -0800 schrieb Sam Roberts: On Mon, Nov 29, 2010 at 9:08 AM, Pascal Schnurr pasc...@boscowitch.de wrote: Hi recently I noticed that i can't search with the like '%searchword%' syntax on an FTS3 virtual table. I'm no expert, but are you sure? This exact example, using LIKE, appears in the FTS3 docs: http://www.sqlite.org/fts3.html#section_1 ___ 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] SQLITE transactions failing with multiple threads
Drake, I am using SQLITE in threadsafe mode. Transaction inside another transaction isnt that equivalent of nested transactions? Should that be allowed? I have no problem opening another handle but just trying to understand the intricacies, thanks. Drake Wilson-3 wrote: Quoth cricketfan srtedul...@yahoo.co.in, on 2010-11-30 07:49:36 -0800: Also not that both threads are using the same handle passed by main. No, don't do that. Using the same handle in two threads concurrently can break depending on the SQLite threading mode, and will gain you no parallelism in the modes where it works. Aside from that, transaction state is bound to a handle; you're starting a transaction and then trying to start another one inside it. Open two handles instead. -- View this message in context: http://old.nabble.com/SQLITE-transactions-failing-with-multiple-threads-tp30340806p30343167.html Sent from the SQLite mailing list archive at Nabble.com. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] SQLITE transactions failing with multiple threads
Quoth cricketfan srtedul...@yahoo.co.in, on 2010-11-30 12:11:52 -0800: Drake, I am using SQLITE in threadsafe mode. Transaction inside another transaction isnt that equivalent of nested transactions? Should that be allowed? SQLite has named savepoints, but not nested BEGIN transactions. It's hard to tell what exactly you're doing from the description, such as why you're doing these updates with two threads to start with, so it's hard to give good advice. Perhaps you could show some example code? Which threading mode do you mean? Serialized or multithreaded? --- Drake Wilson ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Some floats of 15 digits or less do not round-trip
On Tue, Nov 30, 2010 at 12:29 AM, Shane Harrelson sh...@sqlite.org wrote: It turns out the same problem exists on Linux (I used sqlite3-3.7.3.bin); for example: sqlite create table t1(d float); sqlite insert into t1 values(9.87e+31); sqlite select * from t1; 9.870001e+31 So it seems that extended precision is not enough, and to fix the problem, higher precision is needed. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] cost of sqlite3_open
It's not contradictory. I say that real cost of sqlite3_open is parsing the schema. Igor says that this cost is actually deferred from inside sqlite3_open call to the first substantive sqlite3_step call. So you will have to pay this price anyway, just profiler output would be somewhat confusing. I agree that the price has to be paid somewhere in time. The issue I raised was about the precise moment in was occuringin time, nothing else. Nothing really important anyway. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] SQLITE transactions failing with multiple threads
Drake, It is in serialized mode. Opening another handle did resolve the issue. I am doing inserts in one thread and then if necessary update the same using another thread. Drake Wilson-3 wrote: Quoth cricketfan srtedul...@yahoo.co.in, on 2010-11-30 12:11:52 -0800: Drake, I am using SQLITE in threadsafe mode. Transaction inside another transaction isnt that equivalent of nested transactions? Should that be allowed? SQLite has named savepoints, but not nested BEGIN transactions. It's hard to tell what exactly you're doing from the description, such as why you're doing these updates with two threads to start with, so it's hard to give good advice. Perhaps you could show some example code? Which threading mode do you mean? Serialized or multithreaded? --- Drake Wilson ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users -- View this message in context: http://old.nabble.com/SQLITE-transactions-failing-with-multiple-threads-tp30340806p30343885.html Sent from the SQLite mailing list archive at Nabble.com. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] SQLITE transactions failing with multiple threads
On 30 Nov 2010, at 8:11pm, cricketfan wrote: Drake, I am using SQLITE in threadsafe mode. Transaction inside another transaction isnt that equivalent of nested transactions? Should that be allowed? I have no problem opening another handle but just trying to understand the intricacies, thanks. The database handle is not just a pointer to the file on disk, it's used to store some details and state of the current operation. The way you're using a single handle tries to cram the state of two different operations in it at once. It's not going to work. If you have two different threads that might access the database at the same time, you need two different handles. You could get rid of the problem by implementing some sort of semaphore system between your threads to prevent them using the database at the same time. But that would defeat the point of using two threads in the first place. So it's probably best to let SQLite handle the semaphoring for you, by using two different handles. Simon. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Just compiled SQLite in Visual Studio
OK then I have a newbee question that is actually out of the scope of SQLite. If the only difference between C and C++ is the file extension, then what is the difference between C and C++? I'm thinking of adding a language other than the Visual Basic that I kind of know and would like to know the difference. I've been thinking about Java, but am not sure yet. Bob Keeland --- On Tue, 11/30/10, john darnell john.darn...@walsworth.com wrote: From: john darnell john.darn...@walsworth.com Subject: Re: [sqlite] Just compiled SQLite in Visual Studio To: General Discussion of SQLite Database sqlite-users@sqlite.org Date: Tuesday, November 30, 2010, 10:25 AM Thanks Igor. -Original Message- From: sqlite-users-boun...@sqlite.org [mailto:sqlite-users-boun...@sqlite.org] On Behalf Of Igor Tandetnik Sent: Monday, November 29, 2010 7:11 PM To: sqlite-users@sqlite.org Subject: Re: [sqlite] Just compiled SQLite in Visual Studio john darnell john.darn...@walsworth.com wrote: I just added it to a Visual Studio 8 project, turned off the use of precompiled headers (the project is a C++ project) and compiled the SQLite.c file without any errors. There is no such thing as a C++ project. A project in Visual Studio can happily contain both C and C++ files. By default, file extension determines whether the file is compiled with C or C++ compiler (.c would indicate C), and this could also be overridden in project settings on a per-file basis. -- Igor Tandetnik ___ 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] Just compiled SQLite in Visual Studio
On 1 Dec 2010, at 1:01am, Bob Keeland wrote: OK then I have a newbee question that is actually out of the scope of SQLite. If the only difference between C and C++ is the file extension, No. then what is the difference between C and C++? I'm thinking of adding a language other than the Visual Basic that I kind of know and would like to know the difference. I've been thinking about Java, but am not sure yet. Argh. C++ is C, with some additional features added to all object-oriented programming and some other stuff. So every C program is a C++ program, with the programmer never having chosen to use those extra facilities. And every C++ compiler can compile a C program. Simon. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Just compiled SQLite in Visual Studio
Igore didn't mean there is no difference between C and C++. He was just saying a 'project' isn't C or C++. In other words, C and C++ have different (though similar) compiler rules, syntax, etc. By default, the compiler will compile a '.c' file using the C rules, and a '.cpp' file with the C++ rules. And you can mix .c and .cpp files in the same project. As for what the difference is? That's a big question. Objects exist in C++, and they don't in C. That's the tip of the iceberg. Doug -Original Message- From: sqlite-users-boun...@sqlite.org [mailto:sqlite-users-boun...@sqlite.org] On Behalf Of Bob Keeland Sent: Tuesday, November 30, 2010 5:02 PM To: General Discussion of SQLite Database Subject: Re: [sqlite] Just compiled SQLite in Visual Studio OK then I have a newbee question that is actually out of the scope of SQLite. If the only difference between C and C++ is the file extension, then what is the difference between C and C++? I'm thinking of adding a language other than the Visual Basic that I kind of know and would like to know the difference. I've been thinking about Java, but am not sure yet. Bob Keeland --- On Tue, 11/30/10, john darnell john.darn...@walsworth.com wrote: From: john darnell john.darn...@walsworth.com Subject: Re: [sqlite] Just compiled SQLite in Visual Studio To: General Discussion of SQLite Database sqlite-users@sqlite.org Date: Tuesday, November 30, 2010, 10:25 AM Thanks Igor. -Original Message- From: sqlite-users-boun...@sqlite.org [mailto:sqlite-users-boun...@sqlite.org] On Behalf Of Igor Tandetnik Sent: Monday, November 29, 2010 7:11 PM To: sqlite-users@sqlite.org Subject: Re: [sqlite] Just compiled SQLite in Visual Studio john darnell john.darn...@walsworth.com wrote: I just added it to a Visual Studio 8 project, turned off the use of precompiled headers (the project is a C++ project) and compiled the SQLite.c file without any errors. There is no such thing as a C++ project. A project in Visual Studio can happily contain both C and C++ files. By default, file extension determines whether the file is compiled with C or C++ compiler (.c would indicate C), and this could also be overridden in project settings on a per-file basis. -- Igor Tandetnik ___ 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 __ Information from ESET NOD32 Antivirus, version of virus signature database 5662 (20101130) __ The message was checked by ESET NOD32 Antivirus. http://www.eset.com ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Just compiled SQLite in Visual Studio
On Wed, Dec 01, 2010 at 01:10:51AM +, Simon Slavin scratched on the wall: So every C program is a C++ program, Not true. Try to compile sqlite3.c with a C++ compiler and see how far you get. -j -- Jay A. Kreibich J A Y @ K R E I B I.C H Intelligence is like underwear: it is important that you have it, but showing it to the wrong people has the tendency to make them feel uncomfortable. -- Angela Johnson ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Just compiled SQLite in Visual Studio
Oh, from the various replies I see that C++ is a more capable extension of C. Igor was only using a figure of speech, kind of. Sorry about the newbee question, but thanks for the replies. Bob Keeland --- On Tue, 11/30/10, Simon Slavin slav...@bigfraud.org wrote: From: Simon Slavin slav...@bigfraud.org Subject: Re: [sqlite] Just compiled SQLite in Visual Studio To: General Discussion of SQLite Database sqlite-users@sqlite.org Date: Tuesday, November 30, 2010, 7:10 PM On 1 Dec 2010, at 1:01am, Bob Keeland wrote: OK then I have a newbee question that is actually out of the scope of SQLite. If the only difference between C and C++ is the file extension, No. then what is the difference between C and C++? I'm thinking of adding a language other than the Visual Basic that I kind of know and would like to know the difference. I've been thinking about Java, but am not sure yet. Argh. C++ is C, with some additional features added to all object-oriented programming and some other stuff. So every C program is a C++ program, with the programmer never having chosen to use those extra facilities. And every C++ compiler can compile a C program. Simon. ___ 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] Just compiled SQLite in Visual Studio
On 11/30/2010 10:18 PM, Doug wrote: Objects exist in C++, and they don't in C actually objects can and do exist in C, it's just a matter of writing them. C++ added the extensions to make writing/managing them easier. http://www.google.com/search?q=object+oriented+programming+in+Cie=utf-8oe=utf-8aq=trls=org.mozilla:en-US:officialclient=firefox-a ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Just compiled SQLite in Visual Studio
On 1 Dec 2010, at 1:33am, Jay A. Kreibich wrote: On Wed, Dec 01, 2010 at 01:10:51AM +, Simon Slavin scratched on the wall: So every C program is a C++ program, Not true. Try to compile sqlite3.c with a C++ compiler and see how far you get. Can you explain the problem to me ? The only C++ compiler I have here handles Obj-C as well and has no problem with it. Simon. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Just compiled SQLite in Visual Studio
On 11/30/2010 8:42 PM, Simon Slavin wrote: On 1 Dec 2010, at 1:33am, Jay A. Kreibich wrote: On Wed, Dec 01, 2010 at 01:10:51AM +, Simon Slavin scratched on the wall: So every C program is a C++ program, Not true. Try to compile sqlite3.c with a C++ compiler and see how far you get. Can you explain the problem to me ? The only C++ compiler I have here handles Obj-C as well and has no problem with it. which compiler are you using? ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Just compiled SQLite in Visual Studio
Bob Keeland keela...@yahoo.com wrote: OK then I have a newbee question that is actually out of the scope of SQLite. If the only difference between C and C++ is the file extension, then what is the difference between C and C++? Since the premise of the question is false, any conclusion whatsoever may logically follow. C and C++ are two separate languages, somewhat related but nevertheless distinct. Just as it is customary to give Java sources a .java extension, it is customary to give C sources a .c extension and C++ sources a .cpp or .cc or sometimes .c++ extension. Just as the choice of file extension is not the only difference between Java and C++ (or Python, or Perl, or whatever), it's not the only difference between C and C++. Igor Tandetnik ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Just compiled SQLite in Visual Studio
Simon Slavin slav...@bigfraud.org wrote:
So every C program is a C++ program
Not quite true. Here are a few examples that are valid C but invalid C++:
/* implicit 'int' return type */
f();
/* implicit conversion from void* to any pointer type */
char* p = malloc(100);
// calling a function without first declaring it.
undeclared(42);
// KR style function definitions.
void f(x)
int x;
{
}
It is true, however, that it's fairly easy to transform any C program into a
program that's both valid C and C++, by applying straightforward modifications
- tightening type safety and such.
--
Igor Tandetnik
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Re: [sqlite] Just compiled SQLite in Visual Studio
On 1 Dec 2010, at 1:46am, Reid Thompson wrote: On 11/30/2010 8:42 PM, Simon Slavin wrote: On 1 Dec 2010, at 1:33am, Jay A. Kreibich wrote: On Wed, Dec 01, 2010 at 01:10:51AM +, Simon Slavin scratched on the wall: So every C program is a C++ program, Not true. Try to compile sqlite3.c with a C++ compiler and see how far you get. Can you explain the problem to me ? The only C++ compiler I have here handles Obj-C as well and has no problem with it. which compiler are you using? Oh. No matter. It's the one Apple's Xcode calls and it's being very clever about what language it's compiling. It defeated my test. Simon. ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Just compiled SQLite in Visual Studio
Bob Keeland keela...@yahoo.com wrote: Oh, from the various replies I see that C++ is a more capable extension of C. Igor was only using a figure of speech, kind of. Everything I said in this thread so far, I meant quite literally. Which expression of mine do you take as a figure of speech? -- Igor Tandetnik ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Just compiled SQLite in Visual Studio
On 11/30/2010 9:04 PM, Simon Slavin wrote: Oh. No matter. It's the one Apple's Xcode calls and it's being very clever about what language it's compiling. It defeated my test. Simon. a quick google query seems to imply that Xcode uses the Gnu Compiler Collection (gcc, g++, gcj, gfortan, etc) see http://en.wikipedia.org/wiki/GNU_Compiler_Collection the STRUCTURE section about midway down and http://gcc.gnu.org/ for the complete details ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
Re: [sqlite] Just compiled SQLite in Visual Studio
On Nov 30, 2010, at 18:04, Igor Tandetnik wrote:
It is true, however, that it's fairly easy to transform any C program into a
program that's both valid C and C++, by applying straightforward
modifications - tightening type safety and such.
Except there are a lot of areas where C advanced in C99 that C++ can't
deal with in current versions:
item_info info = { .nvalue = 1 };
struct {
char blah[];
}
char blah[somevariable];
The ability to sprintf a size_t or any general 64-bit number.
(and a few other things that are really convenient, but have got in my
way in attempts to port c code to c++).
--
dustin sallings
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Re: [sqlite] Just compiled SQLite in Visual Studio
Dustin Sallings dus...@spy.net wrote: On Nov 30, 2010, at 18:04, Igor Tandetnik wrote: It is true, however, that it's fairly easy to transform any C program into a program that's both valid C and C++, by applying straightforward modifications - tightening type safety and such. Except there are a lot of areas where C advanced in C99 that C++ can't deal with in current versions True. I should have clarified that I meant a C90 program. In my defense, I work primarily with Visual Studio compilers, which don't support C99 (except for the most trivial features, e.g. // comments). -- Igor Tandetnik ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
[sqlite] Fwd: [sqlite-dev] SQLIte 64bit precompiled libraries for Windows
Is there anyone publishing stable version of precompiled binaries of sqlite for Windows 64-bit ? I understand from the below sqlite.org doesn't, but there maybe another site? Thanks -- Forwarded message -- From: Dan Kennedy danielk1...@gmail.com Date: Tue, Nov 30, 2010 at 6:58 PM Subject: Re: [sqlite-dev] SQLIte 64bit precompiled libraries for Windows To: sqlite-...@sqlite.org On 11/30/2010 11:17 PM, Saar Carmi wrote: Hi Are there precompiled libraries for Windows 64bit available? Or should I compile it myself ? Not available from sqlite.org. For this kind of question, use the sqlite-users mailing list. This mailing list is really for discussion of SQLite core development and has only a small number of readers. ___ sqlite-dev mailing list sqlite-...@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-dev ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
