Re: [sqlite] Constraint failed infos

2011-08-11 Thread Pavel Ivanov
This is a known issue and it has an open ticket: http://www.sqlite.org/src/tktview?name=23b2128201. Pavel On Wed, Aug 10, 2011 at 1:05 PM, Julien Laffaye wrote: > Hello, > > Is it possible to get more info when I get a constraint failed error > from the C API? > I am interested in the column na

Re: [sqlite] SQLite + unicode

2011-08-11 Thread Pavel Ivanov
> Don't use sqlite3_exec. Use sqlite3_prepare16 (which accepts wchar_t*), > sqlite3_step, sqlite3_finalize. Read text from columns with > sqlite3_column_text16 (which returns wchar_t*). I'd say it's not exactly this way. AFAIK, wchar_t on Linux is 32-bit, but sqlite3_column_text16 will return 16

Re: [sqlite] In memory v/s tmpfs

2011-08-10 Thread Pavel Ivanov
t; On Wed, Aug 10, 2011 at 11:35 PM, Pavel Ivanov wrote: > >> > If you have one reader and many writers, consider PRAGMA >> journal_mode=WAL; >> >> Richard meant "one writer and many readers" of course. >> >> >> If the other process opens t

Re: [sqlite] In memory v/s tmpfs

2011-08-10 Thread Pavel Ivanov
> If you have one reader and many writers, consider PRAGMA journal_mode=WAL; Richard meant "one writer and many readers" of course. >> If the other process opens the db connection as read_only, will the hot >> journal check be still done (during queries operations of the second >> process)? >> >

Re: [sqlite] In memory v/s tmpfs

2011-08-09 Thread Pavel Ivanov
> Journal mode is WAL I believe in-memory database can't have journal mode WAL. So you compare completely different settings. Pavel On Tue, Aug 9, 2011 at 5:15 AM, wrote: > > Journal mode is WAL > > > --Original Message-- > From: Roger Binns > Sender: sqlite-users-boun...@sqlite.org

Re: [sqlite] In memory v/s tmpfs

2011-08-08 Thread Pavel Ivanov
> What could be a possible explanation for this behaviour? > One difference int configurations is that the sqlite lib is built for > multithreading in the tmpfs scenario. Could it be an overhead of mutexes? Make tests with the same SQLite library. Run test with tmpfs using strace to see if files

Re: [sqlite] Exclusive locking mode not working as expected?

2011-07-29 Thread Pavel Ivanov
> Am I missing something here or if I want to prevent this, is my only option > to modify our build of SQLite to open the file for exclusive access? Yes, opening with exclusive access is the only option for you. But with latest SQLite version you don't have to modify SQLite sources for that. You

Re: [sqlite] Editing SQL commands in sqlite3

2011-07-28 Thread Pavel Ivanov
If you configure and compile sqlite3 command line yourself and your system have readline installed then yes. Pavel On Thu, Jul 28, 2011 at 4:08 PM, wrote: > Is it possible to edit commands entered on the sqlite3 command line? > > > > > > ___ > sqlite

Re: [sqlite] trying to build from sqlite-3.6.7 on ubuntu 11.04, missing sqlite3.c

2011-07-26 Thread Pavel Ivanov
>  as part of an embedded system build, i'm building a number of tools > for the *host* system, including sqlite-3.6.7 from the tarball (along > with a few patches which i will be examining shortly). Apparently you are building from canonical sources. Why don't you use amalgamation? It's much easi

Re: [sqlite] Possibility to use a in-mmeory database with two sqlite handles/connections

2011-07-26 Thread Pavel Ivanov
> is there a way to create more then one sqlite connection hadles for the > same in-memory database? No. > There was a proposal: > http://www.mail-archive.com/sqlite-users@sqlite.org/msg35438.html > from Markus Lehmann. > Is this a safe sollution? I guess if it's not in the mainline SQLite it's

Re: [sqlite] Loading a database from memory

2011-07-19 Thread Pavel Ivanov
> So you can copy any block of memory you have a handle for into that, use > SQLite to manipulate the data while it's in memory Simon, could you elaborate what you meant by that. To my knowledge you can't just copy any block of memory into SQLite and make it treat this memory block as database. D

Re: [sqlite] Loading a database from memory

2011-07-19 Thread Pavel Ivanov
> I'm starting to get the impression that the only way for me to do this > is to make my own vfs layer... > http://stackoverflow.com/questions/3839158/using-sqlite-with-stdiostream Yes, this is the best way you can do it. Other option is to take that data, save it to some temporary file and then o

Re: [sqlite] Hidding records from the application

2011-07-17 Thread Pavel Ivanov
> I can only control the databases and the libsqlite.so. > Is everything clear? How do you do that, I wonder? Why do you think that applications you don't control will always use your libsqlite.so? They may not use libsqlite.so at all (compile SQLite sources into application) or use whatever libra

Re: [sqlite] Script-friendly execution of sqlite3.exe for initializing a DB

2011-07-14 Thread Pavel Ivanov
> Is anyone aware of another technique for preventing interactive mode from > running?  I've seen this method: > > Sqlite3 -init new.sql new.db .exit How about sqlite3 new.db ".read new.sql" Pavel On Thu, Jul 14, 2011 at 5:20 PM, Marvin Bellamy wrote: > I want to run sqlite3 from a script (ac

Re: [sqlite] Index question about index

2011-07-14 Thread Pavel Ivanov
> could the next query use the tsamov_code index ??: >    select * from tsamov where tsamov_code like 'AFG%' Only after pragma case_sensitive_like = true; Read more about it here: http://www.sqlite.org/optoverview.html#like_opt. Pavel On Thu, Jul 14, 2011 at 11:56 AM, Sebastian Bermudez wro

Re: [sqlite] Attach file/disk DB to memory DB

2011-07-13 Thread Pavel Ivanov
> If I was to attach a database located in a file on disk to a database located > in memory, would the file DB be loaded in memory too, or would its usage > remain disk-based? Its usage would be the same as if you open a new connection to that database file, i.e. disk-based (barring the page cachi

Re: [sqlite] surprising missing query optimization

2011-07-12 Thread Pavel Ivanov
> Now what surprises me is that this optimization is not done > automatically by SQLite. > I suppose I just over estimate the capabilities of the SQLite plan generator. > Or, would this be something that could be improved? It's very non-obvious optimization and I think other type of optimization w

Re: [sqlite] Minimize sqlite3.o size

2011-07-12 Thread Pavel Ivanov
http://www.sqlite.org/compile.html#omitfeatures Make sure you read all important notes and tested your app thoroughly. Pavel On Tue, Jul 12, 2011 at 9:10 AM, Baruch Burstein wrote: > I assume this is the same for sqlite3.dll or sqlite3.lib, but if not, I am > interested in sqlite3.o (mingw32)

Re: [sqlite] DROP TABLE yields SQLITE_LOCKED from user-defined function

2011-07-07 Thread Pavel Ivanov
x27;m assuming this is not a regular pattern that has an idiomatic workaround? > > Ben > > -Original Message- > From: sqlite-users-boun...@sqlite.org > [mailto:sqlite-users-boun...@sqlite.org] On Behalf Of Pavel Ivanov > Sent: 07 July 2011 05:18 PM > To: Gener

Re: [sqlite] DROP TABLE yields SQLITE_LOCKED from user-defined function

2011-07-07 Thread Pavel Ivanov
> Is there something special one needs to do in order to drop a table from > inside a user-defined function? > > To test, I call it simply like so: > SELECT my_function(); It shouldn't be ever possible to change the database from within a function called from SELECT statement. SELECT query doesn'

Re: [sqlite] Java and accented characters

2011-07-03 Thread Pavel Ivanov
> Any idea? Please, anyone can help me? How did you put your data into database? I guess you did that with command line utility. And as your console wasn't set to have UTF-8 charset then contents of pais now is not in UTF-8. But jdbc driver tries to treat it as UTF-8 and so you don't see what you

Re: [sqlite] Ensure that query acts on PRE-SORTED tables

2011-07-01 Thread Pavel Ivanov
nt too. > I'm only interested in the results of BETWEEN when you're looking at x1 and > x2 from the pos order perspective > ie doing the BETWEEN query on 'x1' and 'x2' would be useless from the rowid > perspective/order. > I'll write a better descripti

Re: [sqlite] Ensure that query acts on PRE-SORTED tables

2011-07-01 Thread Pavel Ivanov
BETWEEN 'x1' AND 'x2')"; >                            //bit for t_y omitted. > in the hope that (SELECT * from t_x ORDER BY pos) presents it's results to > SELECT BETWEEN in pos order. > I am concerned about having to specify both xpos and pos and am n

Re: [sqlite] Ensure that query acts on PRE-SORTED tables

2011-07-01 Thread Pavel Ivanov
as to be in there somewhere. > It strikes me that > SELECT pos FROM t_x WHERE txt BETWEEN 'x1' AND 'x2' > needs to be operating on the results returned by > SELECT * FROM t_x BY ORDER BY pos > ie another level of query is required but I'm not sure of how you

Re: [sqlite] sqlite3_create_function and threads

2011-07-01 Thread Pavel Ivanov
>  > Yes. What's wrong with that? > > Nothing at all - I just needed to know whether that was the case so I > could design certain sections of my code accordingly. Three question marks of yours suggested me that you think it's awfully wrong. Note that although your function and application pointe

Re: [sqlite] Ensure that query acts on PRE-SORTED tables

2011-07-01 Thread Pavel Ivanov
existing > ones or at least make it look like that even if the records are physically > appended to the tables. > Hope this clarifies things and look forward to your thoughts. > > > On 1 July 2011 15:30, Pavel Ivanov wrote: > >> >> Putting the 'ORDER BY' clau

Re: [sqlite] sqlite3_create_function and threads

2011-07-01 Thread Pavel Ivanov
> To put it another way, if I call sqlite3_create_function to install a > custom function, is that function now available to all threads using > SQLite or is it available only to the thread that made the > sqlite3_create_function call? Yes, it's available to all threads using the same connection.

Re: [sqlite] Ensure that query acts on PRE-SORTED tables

2011-07-01 Thread Pavel Ivanov
>> Putting the 'ORDER BY' clause in view won't work? > > It will work just fine, in that the results you see will appear in the ORDER > you asked for. I believe that's not always true and is not required by SQL standard. Most probably 'select * from view_name' will return rows in the order writte

Re: [sqlite] help needed to optimize a query

2011-06-28 Thread Pavel Ivanov
> This has to run as fast as possible. A left join between these tables is too > slow, for 10.000 entries it takes around 15 seconds just to navigate through > the cursor, if I add a where clause selecting only one kind of data then it > reduces to less than 5 seconds which is acceptable. What kin

Re: [sqlite] [BUG?] unexpected effect of view nesting on type conversion

2011-06-24 Thread Pavel Ivanov
> Just thought I should add that the problem seems to be gone with the > just released version 3.7.7, but it's not mentioned in the release notes. It's not in release notes but it's in the timeline. See http://www.sqlite.org/src/info/91e2e8ba6f and http://www.sqlite.org/src/info/0b3174e0b1. Pave

Re: [sqlite] openmpi parallel problem

2011-06-22 Thread Pavel Ivanov
> there are no statements open, as far as i can see. Your eyes can miss something. Does sqlite3_close return SQLITE_OK or something else? Pavel On Wed, Jun 22, 2011 at 12:36 PM, Thorsten Kersting wrote: > there are no statements open, as far as i can see. > > On 06/22/2011 05:

Re: [sqlite] openmpi parallel problem

2011-06-22 Thread Pavel Ivanov
Do you check result code of connection closing? Is it successful? If it's not successful then some statements are still active and reading transaction is still open. That could be the reason of error in write process. Pavel On Wed, Jun 22, 2011 at 10:58 AM, Thorsten Kersting wrote: > i use ope

Re: [sqlite] Sqlite database integrity check fails with disk I/O error (10)

2011-06-20 Thread Pavel Ivanov
> Can some one help me why the disk I/O error occured during the > sqlite3_prepare()  statement ? Because while preparing the statement SQLite must read schema from the database. And although in case of integrity check it's not really necessary I think it's still the general rule and is done befor

Re: [sqlite] Opening a database on a Mac

2011-06-17 Thread Pavel Ivanov
>   strcpy(DBEnginePath, "Macintosh HD:Applications:Adobe InDesign > CS5:Plug-Ins:WPC_ID:IndexData.db"); Try to change path here to "/Applications/Adobe InDesign CS5/Plug-Ins/WPC_ID/IndexData.db". Pavel On Fri, Jun 17, 2011 at 3:08 PM, john darnell wrote: > Sorry to send this twice, but I re

Re: [sqlite] [sqlite-dev] Is there an option to not lock during transaction?

2011-06-17 Thread Pavel Ivanov
Fri, Jun 17, 2011 at 1:18 AM, Florian Weimer wrote: > * Pavel Ivanov: > >> To answer your original question: if you disable shared cache, start >> reading transaction on one connection and start writing transaction on >> the other connection then you'll be able to read o

Re: [sqlite] [sqlite-dev] Is there an option to not lock during transaction?

2011-06-13 Thread Pavel Ivanov
> Hmm... unless read_uncommited is persistant somehow; looks like if I > just don't try to use shared cache it works... I thought I had > disabled cache before alone and still got the same results... read_uncommitted works only when shared_cache is on. To answer your original question: if you dis

Re: [sqlite] Bug in composite foreign key constraints.

2011-06-10 Thread Pavel Ivanov
IIRC, there was a bug in enforcement compound foreign keys where one of columns is primary key and it was fixed. So if you take the latest SQLite version I guess you won't see this problem. Pavel On Fri, Jun 10, 2011 at 11:12 AM, Max B wrote: > Hello, > > Please consider this (working) schema

Re: [sqlite] [sqlite-dev] Index problem on Windows

2011-06-09 Thread Pavel Ivanov
> So my next question is then, given that I have some data coming in, in > a random order, and I want an index. What can I do in order for the > performance to be better? Create index only after all data is populated. BTW, this kind of questions will be answered best on a sqlite-users list. sqli

Re: [sqlite] Dynamically loaded sqlite (linux)

2011-06-09 Thread Pavel Ivanov
> I know that I should avoid such things, but just curious, is it something > inside sqlite that probably makes one dynanmically linked and other > dynamically loaded library share global data and can this be avoidable? No, it's Linux linker who works like that. If you have several libraries loade

Re: [sqlite] Table info for a particular query

2011-06-08 Thread Pavel Ivanov
> Is there any way to do something along the lines of PRAGMA > some_command(SELECT * FROM table1 JOIN table2) and have it return A, B, C, > a, b, c as the headers? If you insist on getting results as resultset then there's no way to do that. But you can do the similar thing by using API like sqlit

Re: [sqlite] Sqlite DATE() function. Add a variable amount of months.

2011-06-08 Thread Pavel Ivanov
> The main issue for me here is that the +1 is inside the string '+1 month' > and i thus cant use a subquerry of the type SELECT date('now','+(SELECT id > FROM table) month'); You can do like this: SELECT date('now','+' || (SELECT id FROM table) || ' month'); Pavel On Wed, Jun 8, 2011 at 1:42

Re: [sqlite] Cannot load SQLite.Interop.dll but file is in the folder

2011-06-08 Thread Pavel Ivanov
s For Windows" on the download page? > Should I re-compile SQLite with the same framework than the one used for > my application? > > Thanks for your support > Cyrille > > > Le 31/05/2011 15:57, Pavel Ivanov a écrit : >> I would ask one more question: do they have

Re: [sqlite] Slow rollback - possible causes?

2011-06-07 Thread Pavel Ivanov
o, should the WAL file shrink back to 0 then?  We're issuing "PRAGMA > wal_checkpoint" to the open DB handle. > > -Eric > > On Tue, Jun 7, 2011 at 7:06 PM, Pavel Ivanov wrote: >>> (Actually, that was another general question we had, should that WAL >>&

Re: [sqlite] Slow rollback - possible causes?

2011-06-07 Thread Pavel Ivanov
l try to catch > the WAL size and see if it changes dramatically. > > (Actually, that was another general question we had, should that WAL > file ever shrink during use?  Why would it grow to that size at all?) > > -Eric > > On Tue, Jun 7, 2011 at 6:44 PM, Pavel Ivanov w

Re: [sqlite] Slow rollback - possible causes?

2011-06-07 Thread Pavel Ivanov
> DB file in WAL mode, checkpointing done every 5 seconds by separate > thread in program Depending on the mode of checkpointing you use it can fail if there are some other reading or writing transactions in progress. And at the time you observe very long rollback actual checkpointing happens beca

Re: [sqlite] HELP : how to use datetime('column', 'localtime') as a part of sql string

2011-06-02 Thread Pavel Ivanov
06-02 12:31:59|COMPLETE|md|2011-06-02 07:02:25 > 727|automatedTest_1306496245310334336328084528|2011-06-02 > 12:24:48|COMPLETE|md|2011-06-02 06:55:29 > 726|automatedTest_130648151940731961056560|2011-06-01 > 12:30:33|COMPLETE|md|2011-06-01 07:01:04 > 725|automatedTest_130651279595

Re: [sqlite] HELP : how to use datetime('column', 'localtime') as a part of sql string

2011-06-02 Thread Pavel Ivanov
rote: >> >> The returned value is displayed to the user. We are not storing back the >> returned column. >> >> Sridhar >> >> On 02-06-2011 19:28, Pavel Ivanov wrote: >>>> >>>> but is returning the value stored in the database when exe

Re: [sqlite] HELP : how to use datetime('column', 'localtime') as a part of sql string

2011-06-02 Thread Pavel Ivanov
> but is returning the value stored in the database when executed > as a part of a java program. Can  anyone help me if I am missing > something here ? Looks like your java program runs with a different locale than SQLite Manager. I'm not sure why it thinks that you are in a UTC timezone. Maybe th

Re: [sqlite] Bug reports

2011-06-02 Thread Pavel Ivanov
> I did try sending a mail over the dev-list, but got no reply. Could > someone tell me how it should be done? You should send it here with the exact steps of reproducing the bug. Hopefully your tool is not code analyzer because "potential bugs" without any real life steps to catch it won't be pa

Re: [sqlite] Trigger help needed

2011-06-01 Thread Pavel Ivanov
> CREATE TRIGGER ts_update after update on ip_timestamps when This means that your trigger fires after each UPDATE statement. But > I'm adding/updating records with statements like: > > INSERT OR REPLACE into ip_timestamps VALUES ( "182.71.33.222" , 1306932777 ); you do INSERT statements, so you

Re: [sqlite] TRANSACTIONs

2011-06-01 Thread Pavel Ivanov
ent to read uncommitted data in the same transaction. Pavel On Wed, Jun 1, 2011 at 2:57 PM, Robert Myers wrote: > On 6/1/2011 1:47 PM, Pavel Ivanov wrote: >>> Actually, you do know what SQLite does without knowing the internals. It >>> claims to be serializable and

Re: [sqlite] TRANSACTIONs

2011-06-01 Thread Pavel Ivanov
can find a link on sqlite.org for you when I have some spare time). Pavel On Wed, Jun 1, 2011 at 2:41 PM, Robert Myers wrote: > On 6/1/2011 1:23 PM, Simon Slavin wrote: >> On 1 Jun 2011, at 7:12pm, Jan Hudec wrote: >> >>> On Wed, Jun 01, 2011 at 10:17:02 -0400, Pavel Ivan

Re: [sqlite] TRANSACTIONs

2011-06-01 Thread Pavel Ivanov
>  From within a BEGIN TRANSACTION and END TRANSACTION block, should I not > update the same row in a table more than once? You can update it as many times as you need. > What are the exact limitations on what I can do during a Transaction? Do not update a table if there is some select statement

Re: [sqlite] Cannot load SQLite.Interop.dll but file is in the folder

2011-05-31 Thread Pavel Ivanov
I would ask one more question: do they have the same Windows and .NET Framework version as you have? AFAIK, Windows and .NET specifically are very picky on all dlls versions. So if for example you have SQLite.Interop.dll compiled with a newer .NET Framework and manifest in it requires your version

Re: [sqlite] SQLite in Xcode

2011-05-26 Thread Pavel Ivanov
> Here are two errors out of the 1200+ errors generated (I tried to include as > much information as possible to help identify the problem.  Please forgive if > I am overdoing it...): > >        Compiling /.../sqlite3.c >        Error:invalid conversion from "void *" to "char *" >        This err

Re: [sqlite] SQLite in Xcode

2011-05-26 Thread Pavel Ivanov
> 2.)     I moved SQLite3.c and SQLite3.h into my source folder and added them > to the project.  I made no changes to the code nor did I do anything special > when I added them to my project (i.e. I did not set any special compile > flags-I simply added the two files to the project). > 3.)    

Re: [sqlite] Incorrect left join behavior?

2011-05-25 Thread Pavel Ivanov
> I can use two left joins.  While writing the first left join, I discovered > that it is behaving like an inner join. > > select * > from test a >   left join test b on a.component = b.component > where a.machine = 'machine1' >   and b.machine = 'machine2'; By the WHERE condition you limit result

Re: [sqlite] Using sqlite.net with Linq to create database

2011-05-24 Thread Pavel Ivanov
without issuing this command then it can't be used with SQLite. Pavel On Tue, May 24, 2011 at 11:05 AM, Ruth Ivimey-Cook wrote: > Pavel Ivanov wrote: >>> If I try to query database existence using Linq's "DatabaseExists" I get >>> a NotImplemented except

Re: [sqlite] Using sqlite.net with Linq to create database

2011-05-24 Thread Pavel Ivanov
> If I try to query database existence using Linq's "DatabaseExists" I get > a NotImplemented exception in the sqlite ChangeDatabase function - which > doesn't make sense to me. SQLite doesn't have a notion of server containing several databases. That's why it makes perfect sense that SQLite doesn

Re: [sqlite] Multi-threading Common Problem

2011-05-24 Thread Pavel Ivanov
tioned I should be using SQLite-specific mechanisms to achieve the same > results.  I am just trying to understand how to do that.  Pthread_rwlock() > works fine. > > Thanks, > > John > > --- On Tue, 5/24/11, Pavel Ivanov wrote: > >> From: Pavel Ivanov >>

Re: [sqlite] Multi-threading Common Problem

2011-05-24 Thread Pavel Ivanov
> I have all writes in transactions.  If I deactivate my pthread_rwlock() that > enforce the above, several writes fail with a "database locked" error (I > assume it is returning SQLITE_BUSY). > > So how do I implement the equivalent of a pthread_rwlock() using SQLite > mechinisms? When SQLITE_

Re: [sqlite] (no subject)

2011-05-19 Thread Pavel Ivanov
> Is there a rationale for allowing such statements or is that an effect > of the 'Lite' nature?  (Note: I'm not complaining, just asking.) I believe that's an effect of the "typeless" design. As SQLite doesn't have strict type names for columns it accepts pretty much anything for that. So in your

Re: [sqlite] Query efficiency

2011-05-19 Thread Pavel Ivanov
gt; from ab where ab.a_id2 = 1 and ab.b_id = 1) ; > 1|1 > 1|2 > 2|1 > sqlite> select aa.* from aa ar, ab ab1, ab ab2; > Error: no such table: aa > sqlite> select aa.* from aa as ar, ab ab1, ab ab2; > Error: no such table: aa > sqlite> > > At this point I got

Re: [sqlite] SQL Statement Help(selecting days).

2011-05-18 Thread Pavel Ivanov
> I need help to build a statement in order to select all days free from > events in a specific time range. This kind of task should be implemented in your application. SQL wasn't intended for and can't solve such tasks. Pavel On Wed, May 18, 2011 at 4:06 PM, Danilo Cicerone wrote: > Hi to al

Re: [sqlite] Query efficiency

2011-05-17 Thread Pavel Ivanov
> That is, is leaving it to the > query optimiser to figure out that I only need the sub select once the > best thing to do? AFAIK, SQLite's optimizer is not that smart to collapse two identical sub-queries and reuse once generated result. > Is the select I'm doing where both a_id1 & 2 are "in" t

Re: [sqlite] threading and grand central dispatch (OS X/iOS)

2011-05-15 Thread Pavel Ivanov
> I'm still not 100% sure if there's a problem sharing connections across > threads with SQLITE_OPEN_NOMUTEX as long as I guarantee that they aren't > concurrent. I suspect there aren't, but I'm not 100% sure. Any case where > sqlite3 would be less than happy that pthread_self wasn't always the

Re: [sqlite] Common Multi-treaded Problem

2011-05-14 Thread Pavel Ivanov
stablished than the later. > > Again thanks for the information and I apologize for taking up so much list > bandwidth.  I hope others can benefit. > > John > > --- On Thu, 5/12/11, Pavel Ivanov wrote: > >> From: Pavel Ivanov >> Subject: Re: [sqlite] Common Multi

Re: [sqlite] IN clause in search query to search a single field containing comma delimited values

2011-05-13 Thread Pavel Ivanov
> SELECT categories FROM myTable WHERE (","||categories||",") LIKE "%,7,%"; > > but I'm guessing LIKE isn't as efficient, and the query is more > awkward.  Any advise would be appreciated.  Thanks! This LIKE is the only way to get information from your table. But you can do it more efficiently by

Re: [sqlite] Common Multi-treaded Problem

2011-05-12 Thread Pavel Ivanov
in the discussion... > > On Thu, 12 May 2011 17:58:40 -0400 > Pavel Ivanov wrote: > >> There's no dependency between different prepared statements, but there >> is dependency between transactions as they use the same database. And >> transaction cannot be finishe

Re: [sqlite] Common Multi-treaded Problem

2011-05-12 Thread Pavel Ivanov
select prepared statement will lock the DB from other threads > (or is it DB connections?) but not the current thread (or is it DB > connection). > > Thanks for the help! > > John > > --- On Thu, 5/12/11, Pavel Ivanov wrote: > >> From: Pavel Ivanov >> Sub

Re: [sqlite] Common Multi-treaded Problem

2011-05-12 Thread Pavel Ivanov
> Interesting is the impression I had with prepared statements was the reset > was only necessary if you wanted to reuse that statement.  Since each each DB > connection is in its own instance of a class (with it own set of prepared > statements) I would not think there would be any dependency o

Re: [sqlite] Multi-threading Common Problem

2011-05-12 Thread Pavel Ivanov
> "After a BEGIN EXCLUSIVE, no other database connection except for > read_uncommitted connections will be able to read the database and no other > connection without exception will be able to write the database until the > transaction is complete." > > This tells me that reads outside of a tran

Re: [sqlite] Can I dynamically select a table ?

2011-05-11 Thread Pavel Ivanov
> I can't trully construct sql statement piece by piece with SQL > db as I did with Oracle. Just wanted to confirm. Why do you need to construct SQL specifically with db's tools? Why can't you do that in your host language? Oracle needs dynamic SQL feature because it will work much faster than the

Re: [sqlite] Three questions

2011-05-11 Thread Pavel Ivanov
> Therefore, the second insert fails on every database system i ever > encountered. Apparently you didn't encounter Oracle. In such situation Oracle freezes transaction B until transaction A is committed or rollbacked. After that it knows what to return to transaction B - error or success corresp

Re: [sqlite] Three questions

2011-05-11 Thread Pavel Ivanov
>> 00:01 Transaction A: BEGIN >> 00:02 Transaction B: BEGIN >> 00:03 Transaction A: INSERT INTO test VALUES (1) // works okay >> 00:04 Transaction B: INSERT INTO test VALUES (1) // aborts with 'duplicate >> key' error! why??? > > I get SQLITE_BUSY "database is locked" at this point, as I would exp

Re: [sqlite] Question: Memory-Based Databases

2011-05-10 Thread Pavel Ivanov
> Is this true, or is the memory usage pretty much similar? Until you reach limit set by 'pragma cache_size' memory usage would be the same for in-memory database and on-disk database. When the size of your database grows beyond 'pragma cache_size' in-memory database starts to consume more memory

Re: [sqlite] Addition: Re: SQLite locking question

2011-05-06 Thread Pavel Ivanov
> My understanding of the shared cache model was that it just ist intended > for solving our problem by relaxing the locking a little and that there > should not be any mutexes at all when using the uncomitted read mode. > > Have I missed anything? Yes, you are involved in a "magical" thinking. Al

Re: [sqlite] Query question

2011-05-06 Thread Pavel Ivanov
> sqlite> select * from a where a=10 group by b; > 10|1 > 10|2 > sqlite> select * from a where a=11 group by b; > 11|2 > 11|3 > > How can I do count equivalent of such a query to find out how many > distinct values of b there are for a given a? (That is get an answer of > 2 in the above) select co

Re: [sqlite] Addition: Re: SQLite locking question

2011-05-06 Thread Pavel Ivanov
>> Any other chance to speed this up (apart from the obvious "optimize the >> query, do not use distinct on large tables)= > > Without seeing the query or database schema? Not really... Depending > on the exact query an index on "xyz" might help. Another suggestion could be to turn off shared

Re: [sqlite] INNER JOIN Optimization

2011-05-04 Thread Pavel Ivanov
> The problem is that I would like to avoid splitting the query into two parts. > I would expect SQLite to do the same thing for me automatically (at least in > the second scenario), but it does not seem to happen... Why is that? In short, because SQLite cannot read your mind. To understand the

Re: [sqlite] Compile Error

2011-05-03 Thread Pavel Ivanov
I believe any compilation options that require changes in SQL parser require compiling from original sources as well. They cannot be used with amalgamation file which has already generated SQL parser's code. Pavel On Tue, May 3, 2011 at 3:05 PM, jeff archer wrote: > I am attempting to compile

Re: [sqlite] vacuum and rowids

2011-04-28 Thread Pavel Ivanov
>> which suggests that referring to rowids is fine. > > It does not suggest referring to ROWIDs is fine, it only says that it > can be done.  I think Pavel's point is that referencing ROWIDs is bad > practice, so that is why he says you shouldn't do it. Yes, that's right. You can refer to rowid, b

Re: [sqlite] vacuum and rowids

2011-04-28 Thread Pavel Ivanov
> After more poking, it appears that rowids might not be changed by a vacuum if > I have an index on the table. Is this true? If so, is it something I can rely > on going forward? No, it's not true. The only way to keep your rowids intact is to declare an INTEGER PRIMARY KEY alias for it. And yo

Re: [sqlite] query to find mixed values

2011-04-26 Thread Pavel Ivanov
> REQ3 is a problem because you have mixed signs in INV and only one record in > REP > > How would I craft a query to return REQ3? Could be something like this: select INV.REQ, count(case when INV.AMT > 0 then 1 else null end) positive, count(case when INV.AMT < 0 then 1 else null end) negative,

Re: [sqlite] date field with default current date

2011-04-22 Thread Pavel Ivanov
date and/or time." It won't be your local time. Pavel On Fri, Apr 22, 2011 at 5:46 AM, Fabio Spadaro wrote: > Hi. > > 2011/4/22 Fabio Spadaro > >> Hi >> >> >> 2011/4/22 Fabio Spadaro >> >>> Hi. >>> >>> >>&g

Re: [sqlite] date field with default current date

2011-04-21 Thread Pavel Ivanov
avel On Thu, Apr 21, 2011 at 1:43 PM, Fabio Spadaro wrote: > Hi. > > 2011/4/21 Pavel Ivanov > >> > Does not work on python with sqlite3 module >> >> What does "SELECT sqlite_version()" gives you in python with sqlite3 >> module? >&

Re: [sqlite] date field with default current date

2011-04-21 Thread Pavel Ivanov
> Does not work on python with sqlite3 module What does "SELECT sqlite_version()" gives you in python with sqlite3 module? Pavel On Thu, Apr 21, 2011 at 9:17 AM, Fabio Spadaro wrote: > Hi. > > 2011/4/21 Black, Michael (IS) > >> create table t (d default CURRENT_DATE,i number); >> insert into

Re: [sqlite] just fyi: iPhone and iPad 3G's tracking their owners' movements and saving to sqlite db

2011-04-21 Thread Pavel Ivanov
It's not related to the list but still... > Technically, the data referred to is as follows.  An iPhone logs details of > which phone base stations it connects to, and the 'status' data obtained from > the base station when it was connected.  The location (long & lat) of the > base station is p

Re: [sqlite] Is Lock Table statement spported?

2011-04-20 Thread Pavel Ivanov
Whenever you have doubt like that just go to http://www.sqlite.org/lang.html and see if the statement you are trying to execute exists there and what its correct syntax is. Pavel On Wed, Apr 20, 2011 at 10:40 AM, wrote: > Is LOCK TABLE statement supported by by SQLite? I am getting syntax err

Re: [sqlite] Building sqlite for windows in a proper way

2011-04-19 Thread Pavel Ivanov
> Does anyone one know how to build sqlite to get the same binary as on > download page ? Did you try to remove all those defines that you add at build time and leave only default values set inside sqlite3.c file? Pavel On Mon, Apr 18, 2011 at 8:42 AM, Kuba Nowak wrote: > Hello > > My problem

Re: [sqlite] Performance issues with sqlite3 sqlite3_step function

2011-04-18 Thread Pavel Ivanov
p://www.sqlite.org/changes.html > > Thanks, > Mathias > > > > On Mon 18/04/11 16:05 , "Pavel Ivanov" paiva...@gmail.com sent: > >> I checked >> the SQLite release notes and I could not find changes for sqlite3_step. >> Should I upgrade anyway? &g

Re: [sqlite] Performance issues with sqlite3 sqlite3_step function

2011-04-18 Thread Pavel Ivanov
9:54 AM, Spoerr Mathias wrote: > Hello Pavel, > > thank you for your answer. SQLite Manager uses version 3.7.4, but I checked > the SQLite release notes and I could not find changes for sqlite3_step. > Should I upgrade anyway? > > Thanks, > Mathias > > > > On

Re: [sqlite] Performance issues with sqlite3 sqlite3_step function

2011-04-18 Thread Pavel Ivanov
> Depending on the database size, it sometimes takes minutes to get a result. > But when using the Firefox plugin "SQLite Manager", it "only" takes 1-2 > seconds. > > I use SQLITE Version 3.6.22. Maybe SQLite Manager uses newer version of SQLite? Try to execute in it "SELECT sqlite_version()"

Re: [sqlite] What happens if you insert more than your RAM size into an in memory database?

2011-04-18 Thread Pavel Ivanov
You won't be able to insert. The statement will fail. Pavel On Mon, Apr 18, 2011 at 9:44 AM, Adam DeVita wrote: > Good day, > > What happens if you insert more than your RAM size into an in memory > database? > (I'm particularly interested in the Windows context). > > regards, > Adam >

Re: [sqlite] 'integer'

2011-04-17 Thread Pavel Ivanov
Stefan, > SQLite should'nt be called a "SQL database" (as e.g. touted on its homepage). > Instead it should clearly declare itself as an "In-memory SQL > Datastore" or a "Data container with SQL capabilities". This is quite serious allegations. Making them you should explain what they are based o

Re: [sqlite] Balance between keeping DBs open vs repeated open/close

2011-04-16 Thread Pavel Ivanov
> Keep in mind that sqlite has a limit of 32 open databases. 32 _attached_ databases, not opened. With different sqlite3* handlers you can open as many databases as you want (and your memory permits). Pavel On Thu, Apr 7, 2011 at 6:05 AM, Eduardo wrote: > At 18:11 06/04/2011, you wrote: >>Tha

Re: [sqlite] Corruption on many Windows XP hosts

2011-04-13 Thread Pavel Ivanov
if it worked this way. Pavel On Wed, Apr 13, 2011 at 10:25 AM, Richard Hipp wrote: > On Wed, Apr 13, 2011 at 9:53 AM, Pavel Ivanov wrote: > >> > The fact that one engineer installed a site, began operating the app, >> > then saw it become corrupt minutes later rules o

Re: [sqlite] Corruption on many Windows XP hosts

2011-04-13 Thread Pavel Ivanov
> The fact that one engineer installed a site, began operating the app, > then saw it become corrupt minutes later rules out power loss or hard > resets in at least that case. An operating system level problem should > have been noticed by now given it's Windows XP... And the file is > locally held

Re: [sqlite] Problem setting journal_mode=WAL

2011-04-12 Thread Pavel Ivanov
> If the 'COMMIT' reports that no transaction is active, why is the > JOURNAL_MODE pragma still complaining about it being within a transaction? > Am I missing something here? Probably you have some not finalized SELECT statements still active. To check that you can call sqlite3_close - it will fa

Re: [sqlite] How is the page-cache filled?

2011-04-08 Thread Pavel Ivanov
> * Which version of the source should I use? The amalgamized source > isn't really useful Why it's not useful for you if it contains all the functionality SQLite have? > * Where are pages read and written? I found the page-cache, but not > the functions that read/write those pages to disk. You

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