[sqlite] How to read data from mem?
I want to read the mem when the program is inside the sqlite3VdbeExec() function and in case OP_Insert. Here the mem consists of entire row to be inserted. When I read the mem *pData, I found from the member pData->flags that it contains a BLOB. But when I tried to print BLOB in pData->z, I didnt get correct results. How to print a BLOB? I tried to print the contents in it by performing a deep copy of that mem and converting it to real value using sqlite3VdbeRealValue(). But no satisfactory result. Can someone kindly help me how to get data from mem?
[sqlite] sqlite3_update_hook() clarification
Thank you very much!!
It helped a lot.
On Wed, Mar 9, 2016 at 9:26 PM, Clemens Ladisch wrote:
> Sairam Gaddam wrote:
> > The documentation says that the function sqlite3_update_hook() is called
> > whenever a row is updated, deleted or inserted
>
> No. It says that this function is called to register a callback
> function that is called for these updates.
>
> > And I don't find any definition for this callback routine.
>
> void my_little_callback(void *stuff, int op, const char *db, const char
> *table, sqlite_int64 rowid)
> {
> printf("something was updated\n");
> }
>
> int main()
> {
> ...
> sqlite3_update_hook(db, my_little_callback, NULL);
> ...
> }
>
>
> Regards,
> Clemens
> ___
> sqlite-users mailing list
> sqlite-users at mailinglists.sqlite.org
> http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
>
[sqlite] sqlite3_update_hook() clarification
http://www.sqlite.org/c3ref/update_hook.html The documentation says that the function sqlite3_update_hook() is called whenever a row is updated, deleted or inserted for a rowid table. But I don't find this function to be invoked in my program. When will this function be invoked?? And I am interested in its second parameter which gives the details of table and the rowid of row which is updated. It is a callback function. SQLITE_API void *SQLITE_STDCALL sqlite3_update_hook( sqlite3 *db, /* Attach the hook to this database */ void (*xCallback)(void*,int,char const *,char const *,sqlite_int64), void *pArg/* Argument to the function */ ) And I don't find any definition for this callback routine. Can anyone kindly give information on this?
[sqlite] How to read data from WAL?
> I have done some manual WAL decoding for my forensic software that can > identifiy a previous DB state - its fun :)... > > (From memory) > > To determine which pages belong to the last transaction, you need to : > > Read the WAL header to obtain the current salt, then read each wal > frame to determine which frames belong to the current transaction and > then you can get the page number from the frame. > > To determine which table/index the page belongs to you will need to > check each b-tree (making sure that you take account of pages that are > in the current WAL checkpoint - i.e. exist in the WAL prior to the > page you are looking for). > > You will then need to manually decode each page you have identified in > the WAL to get the rows within the page and then you need to determine > what rows have been added/deleted or altered. > > The issues here are that a small change to a table (one row > added/edited) can result in many changes to the pages for that table, > e.g. if a string is appended to then the row may no longer fit in the > page that it currently occupies so the row will be moved. Depending on > the key structure for the table this may also result in other rows > being moved to maintain the structure of the B-Tree. So if you read a > page from the WAL and then find the* previous version of that page > (which may be earlier in the WAL or in the DB) and a row is not > present you will need to parse all the changed pages in that tree to > determine whether it has been deleted or just moved. > > (* I say THE previous page because you can and very often do have > multiple copies of a page in the WAL.) > > All of the information you need is in the DB file format at the link > provided earlier. It is however not as simple as just reading the > format spec though, it took me a lot of experimentation (including > writing some DB/WAL page level visualisation tools) to work out what > is actually going on. Thanks for the info. I think this is what I need. Can you comment on time complexity in this method?
[sqlite] How to read data from WAL?
> > Sounds to me you want to implement logical decoding, that is to > extract an SQL form from the binary WAL format. > I don't believe SQLite provides such a feature, that is something > other databases use for bidirectional replication. I just want to know which tables and rows are changed from WAL, not necessarily forming a SQL query. If that feature is not present in SQLite. Can you suggest me a good way to achieve that goal? Wal shipping is a good way if you don't need to get bidirectional. Do you mean copying WAL file and placing someplace else when you say WAL shipping? or something else?
[sqlite] How to read data from WAL?
> > To achieve what goal? > > In any case, perhaps https://www.sqlite.org/rbu.html is of interest to > you. > I want to make note of those changes and replicate in another DB. And I found that WAL is the correct place where changes to the database are present. So my main aim is to get those changes and replicate after further processing.
[sqlite] How to read data from WAL?
> > If you're really sure that the database files are identical, the easiest > way to do the replication would be to copy the WAL file. > > What processing do you want to do? > I want to take note of changes and depending on data, I might replicate in some other DB. The database files are not necessarily identical. So mere copying wont help me. I should get the data from WAL and based on which table(can I get these info from WAL?) the data was changed, I should act accordingly. So the only way is to read page and extract information from it or any other way?? > Is there any other better way other than WAL? > > Record the SQL statements that are executed. This is one another case, where some optimization could happen, like for example if I run a update query and nothing gets updated in a particular table which is similar in 2 different databases, then WAL doesn't have any changes on that particular table and no need to execute the same query again in different DB! And I have some other use cases like those. So I would like to see the changes from WAL and based on changes and the query, I will proceed. So i need a better way to read the contents from the WAL. One of them is analyzing the pages from WAL, any others??. In PostgreSQL, for WAL, they have a module which will give summary of which row in a particular table was changed by reading the contents from WAL. Any module like that?? because my work will be easy if I get the info of changes that way!!
[sqlite] How to read data from WAL?
> > This requires detailed knowledge of how SQLite works. If the file format > page I referred you to does not help you may have to study the SQLite > source code to find out what you need. > Yeah I read the source file wal.c and based on what I read, SQLite syncs the frames which have page data in WAL with the main database to update it. But I couldn't find a way to get those changes because they deal with frames and pages. So if I get those WAL frames where page data is stored and read them will I be able to get the changes which are made? And the decryption here I mean is to get information from those pages(like on which table, which column a change is made etc.,) which involves reading the page to get the changes which are presently made. > What are you trying to do ? Are you trying to monitor a program which is > running or recover a corrupt database with some data in the WAL file ? > There are good ways to do these things but they do not involve reading raw > data from the WAL file. > I want to make note of those changes and replicate someplace else. And I found that WAL is the correct place where changes to the database are present. So my main aim is to get those changes and replicate after further processing. Is there any other better way other than WAL?
[sqlite] How to read data from WAL?
My main aim is to find the fresh changes which are to be made to database through WAL module. How is data stored in WAL? If the data is stored in pages inside WAL then how to see the changes which are presently made to the database? Should I decrypt the information from WAL to know the changes which are to be made to the database or any other way? I found some decryption tools which are available for WAL. Will they give changes to be made? Or is there any module readily present inside SQLite which will decrpt the information from WAL? Any information on WAL decryption would be appreciated. Thank you.
[sqlite] WAL checkpoint
Before checkpointing the data from WAL, if the DB is queried, will the result include updated data from WAL or not? Will this situation arise? because writing to WAL and checkpoint occur very fast but if a query comes in between, will the result be updated or not before checkpoint.
[sqlite] Closure.c extension
Is it necessary to have AVL tree in closure tables method and does it result in speed improvements? On Wed, Sep 9, 2015 at 4:59 PM, Richard Hipp wrote: > On 9/9/15, Sairam Gaddam wrote: > > I know that one of the method to compute transitive closure is closure > > tables method. But I didn't understand why AVL tree implementation is > > present in the closure.c extension in order to compute transitive closure > > because the result can be directly queried from the Virtual table(closure > > table). > > > > Can anyone kindly explain what is the significance of AVL tree to compute > > transitive closure ??? > > It is used to implement a priority queue. > -- > D. Richard Hipp > drh at sqlite.org > ___ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users >
[sqlite] Closure.c extension
I know that one of the method to compute transitive closure is closure tables method. But I didn't understand why AVL tree implementation is present in the closure.c extension in order to compute transitive closure because the result can be directly queried from the Virtual table(closure table). Can anyone kindly explain what is the significance of AVL tree to compute transitive closure ???
[sqlite] AVL tree implementation in closure module
Deep inside SQLite source files, there is a module called closure.c for computing transitive closure and it is provided as an extension. Inside, it uses an AVL tree implementation, so why to use that kind of implementation(or importance) for computing transitive closure in this case? And when is the AVL tree populated? because I found that closureInsertNode() function call, which is used to populate the tree are present inside the "xFilter Method" but the purpose of "xFilter Method" method is to search the virtual table. And one more query is that, when(or in which function) the Virtual table(or closure table) is populated so that the "xFilter Method" will begin search of the virtual table. What is the relation between the virtual table and the AVL tree? Can anyone kindly explain my queries???
[sqlite] Regarding root in transitive closure extension of SQLite
> Hello ! > > Look this comment on ext/misc/closure.c: > > -- > > ** When it is created, the new transitive_closure table may be supplied > ** with default values for the name of a table T and columns T.X and T.P. > ** *The T.X and T.P columns must contain integers*. The ideal case is > for > ** T.X to be the INTEGER PRIMARY KEY. The T.P column should reference > ** the T.X column. The row referenced by T.P is the parent of the current > row > Can anyone kindly tell how to extent the support to other data types like Text?
[sqlite] Regarding root in transitive closure extension of SQLite
> > Given that SQLite supports CTE's now, why use that extension? > > AFAIK, it was to add hierarchical query capability to SQLite, which CTE > does builtin now. --DD But will that solve my problem of having the data type of groupId other than Integer primary key like Text???
[sqlite] Regarding root in transitive closure extension of SQLite
I have enabled the transitive closure extension and I followed the steps regarding querying the virtual table mentioned in closure.c file as follows CREATE VIRTUAL TABLE ct1 USING transitive_closure( tablename='group1', idcolumn='groupId', parentcolumn='parentId' ); CREATE TABLE group1( groupId INTEGER PRIMARY KEY, parentId INTEGER REFERENCES group1 ); CREATE INDEX group_idx1 ON group(parentId); SELECT group1.* FROM group1, ct1 WHERE element.groupid=ct1.id AND ct1.root=?1 AND ct1.depth<=2; In the above query, can the root be assigned a text data type? I tried with INTEGER data type for both groupId and parentId, it worked fine but when they are TEXT or INT data type and if I query like ct1.root='SQLITE' there was no output. Can anyone kindly tell help me regarding this ?
[sqlite] How to use gdb for .test files in SQLite?
I was testing a custom SQLite with the test files and one of the file(tclsqlite.test) gave a segmentation fault, when I used Valgrind, it didn't give any stack trace but instead gave the following error. ==5697== ==5697== Process terminating with default action of signal 11 (SIGSEGV): dumping core ==5697== Access not within mapped region at address 0xFFE767F58 ==5697==at 0x4A1CDC: sqlite3VdbeExec (stdio2.h:104) ==5697== If you believe this happened as a result of a stack ==5697== overflow in your program's main thread (unlikely but ==5697== possible), you can try to increase the size of the ==5697== main thread stack using the --main-stacksize= flag. ==5697== The main thread stack size used in this run was 8388608. Can anyone kindly tell what does above error mean? I was not able to find the position of the segmentation fault, will gdb help in this case? Can anyone kindly tell how to use gdb for .test files in order to find origin of the error?
[sqlite] Unable to find the file 'memleak.txt'
> Try "locate memleak" if the file is not present in the working directory > of the process running the test. > > I tried that but there is no file named memleak.txt in the whole system !!!
[sqlite] Unable to find the file 'memleak.txt'
I ran the test files which are present in SQLite for my custom build and I got some memory leaks. I got a message like, Writing unfreed memory log to "./memleak.txt" But I couldn't able to locate that file. Can anyone kindly tell where to find that file or where the unfreed memory log is written ???
[sqlite] How to correctly a add string to a Mem?
I want to make some changes to the result set and I need to add an extra column. On Mon, Jul 13, 2015 at 12:33 PM, Clemens Ladisch wrote: > Sairam Gaddam wrote: > > I have tried a method to create a Mem and add a string to it, which is as > > below > > > > sqlite3VdbeMemSetStr(&(p->custom_aMem[0]), zColumn , > strlen(zColumn)*sizeof(char), SQLITE_UTF8, SQLITE_STATIC); > > This is an internal function that applications are not supposed to know > about. There is no right way to use it because the interface can change > at any time. > > Why are you trying to do this? > > > Regards, > Clemens > ___ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users >
[sqlite] How to correctly a add string to a Mem?
I have tried a method to create a Mem and add a string to it, which is as below sqlite3VdbeMemInit(&(p->custom_aMem[0]), p->db, MEM_Null); memAboutToChange(p,&(p->custom_aMem[0])); sqlite3VdbeMemSetStr(&(p->custom_aMem[0]), zColumn , strlen(zColumn)*sizeof(char), SQLITE_UTF8, SQLITE_STATIC); First I allocated space to Mem and initialized it using sqlite3VdbeMemInit( ) function. Then I changed the Mem and set the value of the string to the Mem using memAboutToChange( ) and sqlite3VdbeMemSetStr( ) respectively. Where zColumn is the string to be added. Is this the correct way to add data to Mem ??? Because when I add data using this method I experienced a memory leak when executing large number of queries. Can anyone kindly tell what is the correct way to add data to Mem ?
[sqlite] Regarding Result Set
Sir,
I created a custom Result set in Resultrow case in sqlite3VdbeExec
function as below
custom_pResultSet = (Mem*) malloc(sizeof (Mem) * (custom_numElements));
and I initialized it using sqlite3VdbeMemInit function.
for( i = 0 ; i < custom_numElements ; i++ )
{
sqlite3VdbeMemInit(_pResultSet[i], p->db,
MEM_Null);
}
Then I copied the first element of custom_pResultSet i.e custom_pResultSet[0]
to
custom_pResultSet[0].z = zColumnSelector;
custom_pResultSet[0].flags = MEM_Str;
custom_pResultSet[0].n = strlen(zColumnSelector);
custom_pResultSet[0].zMalloc = zColumnSelector;
custom_pResultSet[0].enc = SQLITE_UTF8;
I modified the result Custom Result set for select statements and then made
pMem to point to it.
pMem = p->pResultSet = custom_pResultSet;
and then NULL terminated pMem.
I included the code in paste bin * http://pastebin.com/vZuUwXzR
*
The program executed fine when executing less number of queries(less than
60) but when large number of queries(more than 60) are executed then I
found some memory leak form sqlite3VdbeMemNulTerminate function but the
result is found to be correct.
==16096== 160 bytes in 2 blocks are definitely lost in loss record 1 of 1
==16096==at 0x4C2AB80: malloc (in
/usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==16096==by 0x46DACE: sqlite3MemMalloc (sqlite3.c:17131)
==16096==by 0x46E52B: mallocWithAlarm (sqlite3.c:20794)
==16096==by 0x46E5C5: sqlite3Malloc (sqlite3.c:20825)
==16096==by 0x46EE7E: sqlite3DbMallocRaw (sqlite3.c:21191)
==16096==by 0x497721: sqlite3VdbeMemGrow (sqlite3.c:63167)
==16096==by 0x497A50: vdbeMemAddTerminator (sqlite3.c:63278)
==16096==by 0x497ADD: sqlite3VdbeMemNulTerminate (sqlite3.c:63298)
==16096==by 0x4A756D: sqlite3VdbeExec (sqlite3.c:73113)
==16096==by 0x4A00CA: sqlite3Step (sqlite3.c:69462)
==16096==by 0x4A02EC: sqlite3_step (sqlite3.c:69528)
The memory leak is increased while increasing the number of rows in the
tables.
Can anyone kindly explain why there is memory leak when executing large
number of queries ???
Or what should be done to correctly create and NULL terminate Custom result
set ??
[sqlite] Result set creation
I created a custom Result set in Resultrow case in sqlite3VdbeExec function
as below
custom_pResultSet = (Mem*) malloc(sizeof (Mem) * (custom_numElements));
and I initialized it using sqlite3VdbeMemInit function.
for( i = 0 ; i < custom_numElements ; i++ )
{
sqlite3VdbeMemInit(_pResultSet[i], p->db,
MEM_Null);
}
I modified the result Custom Result set for select statements and then made
pMem to point to it.
pMem = p->pResultSet = custom_pResultSet;
and then NULL terminated pMem.
The program executed fine when executing less number of queries(less than
60) but when large number of queries(more than 60) are executed then I
found some memory leak form sqlite3VdbeMemNulTerminate function but the
result is found to be correct.
==16096== 160 bytes in 2 blocks are definitely lost in loss record 1 of 1
==16096==at 0x4C2AB80: malloc (in
/usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==16096==by 0x46DACE: sqlite3MemMalloc (sqlite3.c:17131)
==16096==by 0x46E52B: mallocWithAlarm (sqlite3.c:20794)
==16096==by 0x46E5C5: sqlite3Malloc (sqlite3.c:20825)
==16096==by 0x46EE7E: sqlite3DbMallocRaw (sqlite3.c:21191)
==16096==by 0x497721: sqlite3VdbeMemGrow (sqlite3.c:63167)
==16096==by 0x497A50: vdbeMemAddTerminator (sqlite3.c:63278)
==16096==by 0x497ADD: sqlite3VdbeMemNulTerminate (sqlite3.c:63298)
==16096==by 0x4A756D: sqlite3VdbeExec (sqlite3.c:73113)
==16096==by 0x4A00CA: sqlite3Step (sqlite3.c:69462)
==16096==by 0x4A02EC: sqlite3_step (sqlite3.c:69528)
The memory leak is increased while increasing the number of rows in the
tables.
Can anyone kindly explain why there is memory leak when executing large
number of queries ???
Or what should be done to correctly create and NULL terminate Custom result
set ??
[sqlite] Regarding TCL tests on SQLite
I was testing a custom build of SQLite by TCL test scripts which are present in test folder of SQLite, some of the test scripts like multiplex.test result in an error from the line number 536 which is below 536.faultsim_restore_and_reopen I included the file multiplex.test for further details. Can anyone kindly tell what is the function of "faultsim_restore_and_reopen" and why the error might have occurred? pfa.
[sqlite] faultsim_restore_and_reopen
I was testing a custom build of SQLite by the test scripts which are present in test folder of SQLite, some of the test scripts like multiplex.test, wal4.test etc., have this line faultsim_restore_and_reopen which results in error. Can anyone kindly tell what is the function of "faultsim_restore_and_reopen" and why the error might have occurred?
[sqlite] Will SQLite break a join query?
I know that SQLite will perform some internal select statements when executing a join query but will it break a join query and execute in parts ??? For example if I join 10 tables, will it perform join of 8 and 2 tables at once and in turn join the result of those two joins?
[sqlite] Error while copying the contents of VdbeOp object
How to correctly copy the contents of original VdbeOp aOp which is created by SQlite for some query into another custom VdbeOp object. I tried by normally copying the contents one by one but it resulted in errors. And how to correctly allocate memory to the custom VdbeOp object and how to free the original aOp. So can anyone suggest me the correct way of doing those ? Thanks in advance.
[sqlite] Regarding SQLITE_PRIVATE
On Fri, May 15, 2015 at 4:46 PM, Hick Gunter wrote: > The keyword "static" before a function name limits its visibility to the > current source file. > > But many of the PRIVATE functions are not declared static like the > "sqlite3VdbePrintOp" function. If they do declare, can i know where they did that?
[sqlite] Regarding SQLITE_PRIVATE
On Fri, May 15, 2015 at 4:42 PM, Simon Slavin wrote: > > > By not declaring them in the header file you're meant to be using ? > But I think they are declared in the header. > > ___ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users >
[sqlite] Regarding SQLITE_PRIVATE
On Fri, May 15, 2015 at 3:53 PM, Hick Gunter wrote: > SQLITE_PRIVATE means that the function is PRIVATE. How they achieved PRIVATE functions in C? You are not allowed to call this function, it is not supported as part of > the SQLite API. Because you are not allowed to call the function directly, > it is not made available to the linker. > How those functions are made invisible to the linker?
[sqlite] Tests regarding custom build of SQLite
In order to run .test files(sqlite test codes) in SQLite, I used ./testfixture NAMEOFFILE.test Can anyone kindly tell which build of sqlite will TESTFIXTURE access? Because even when I make modifications to sqlite3.c source code, the output of the test file under test has no effect. And one more question is that, In order to test my custom build of sqlite3.c, I installed both TCL and SQLite, and gave the command ./configure After that the source file sqlite3.c file is formed and I replaced the original sqlite3.c file with my customized sqlite3.c with the same name. But when I ran make test command, the program again replaces my customized sqlite3.c with the original sqlite3.c source file and tests it. So I am not able to run tests on my modified file. So can anyone tell why it replaces with original file and what to do in order to test my custom build.
[sqlite] TCL tests
On Tue, May 12, 2015 at 5:14 PM, Richard Hipp wrote: > > > ./testfixture NAMEOFFILE.test > testfixture.exe NAMEOFFILE.test > > Respectively for unix and windows. > > Thanks! That helped a lot.
[sqlite] TCL tests
On Tue, May 12, 2015 at 5:05 PM, Richard Hipp wrote: > > > Did you try the commands provided above? > > > yeah I tried those commands and installed both tcl and sqlite but i need help in executing the .test file which requires tcl like the one I attached in this mail. pfa.
[sqlite] TCL tests
On Tue, May 12, 2015 at 4:36 PM, Richard Hipp wrote: > > Unix: ./configure; make test > > Windows: nmake /f makefile.msc test > I installed both tcl and sqlite but i need help to run .test files which are present in test folder for sqlite!
[sqlite] TCL tests
But when I tried to run the following message/error pops up : invalid command name "sqlite3_test_control_pending_byte" while executing "sqlite3_test_control_pending_byte 0x001" (file "./tester.tcl" line 92) invoked from within "source $testdir/tester.tcl" (file "attach.test" line 19) How to overcome this ? On Tue, May 12, 2015 at 12:25 PM, Arjen Markus wrote: > Hi Sairam, > > > > That ought to be easy: > > > > tclsh name-of-test-file.test > > > > You will need an installation of Tcl, but these are easy to find. One > place is at ActiveState's site, www.activestate.com/activetcl< > http://www.activestate.com/activetcl>, but it may be that you already > have it on your system. > > > > Regards, > > > > Arjen > > > > > -Original Message----- > > From: sqlite-users-bounces at mailinglists.sqlite.org [mailto:sqlite-users- > > bounces at mailinglists.sqlite.org] On Behalf Of Sairam Gaddam > > Sent: Tuesday, May 12, 2015 8:47 AM > > To: General Discussion of SQLite Database > > Subject: [sqlite] TCL tests > > > > Can anyone kindly help me how to compile and run TCL test scripts ? > > All the test scripts are .test files and I need help in executing them. > > ___ > > sqlite-users mailing list > > sqlite-users at mailinglists.sqlite.org > > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > > > > DISCLAIMER: This message is intended exclusively for the addressee(s) and > may contain confidential and privileged information. If you are not the > intended recipient please notify the sender immediately and destroy this > message. Unauthorized use, disclosure or copying of this message is > strictly prohibited. The foundation 'Stichting Deltares', which has its > seat at Delft, The Netherlands, Commercial Registration Number 41146461, is > not liable in any way whatsoever for consequences and/or damages resulting > from the improper, incomplete and untimely dispatch, receipt and/or content > of this e-mail. > ___ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users >
[sqlite] TCL tests
Can anyone kindly help me how to compile and run TCL test scripts ? All the test scripts are .test files and I need help in executing them.
[sqlite] Testing problem
I installed TCL and then unpacked the SQLite archive, then typed "./configure; make test" what to do next? On Fri, May 8, 2015 at 6:13 PM, Richard Hipp wrote: > On 5/8/15, Sairam Gaddam wrote: > > Is sqllogictest a program which can be downloaded and installed? > > https://www.sqlite.org/sqllogictest/doc/trunk/about.wiki > > > > > > On Fri, May 8, 2015 at 5:21 PM, Richard Hipp wrote: > > > >> On 5/8/15, Sairam Gaddam wrote: > >> > I have custom SQLite and in order to test it I downl > >> > oaded sqlite-src-3081000.zip > >> > (7.29 MiB) as advised, which contains some test files but most of them > >> are > >> > .test files and how to execute them? should I use sqllogictest > program? > >> If > >> > it should be used where is it available? > >> > >> The main public SQLite test suite makes extensive use of TCL. > >> (http://tcl.tk/). On unix or Windows workstations, you simply install > >> TCL then unpack the SQLite archive, then type "./configure; make test" > >> on unix or Windows with MinGW/Msys or "nmake /f Makefile.msc test" > >> under Windows with MSVC. > >> > >> If you are on an embedded system that does not have the infrastructure > >> to support TCL, then you could (as you observe) try to run > >> sqllogictest, which is written in C. But that test suite is really > >> only designed to show that SQLite generates the same results as other > >> database engines for given SQL statements. So it does not test things > >> like file I/O or transactions or non-universal features such as > >> partial indexes, common table expression, virtual tables, etc. > >> > >> The TH3 test suite is plain C code that provides 100% MC/DC is > >> designed to run on embedded systems with minimal support > >> infrastructure. But TH3 is proprietary and is used under license > >> only. See https://sqlite.org/th3.html for additional information. > >> > >> > > >> > And regarding .c test files some of them require tcl.h file which i > >> > could > >> > not find ! I followed the steps given at the starting of each file but > >> > i > >> > dont find them useful. > >> > can anyone help me regarding this? > >> > ___ > >> > sqlite-users mailing list > >> > sqlite-users at mailinglists.sqlite.org > >> > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > >> > > >> > >> > >> -- > >> D. Richard Hipp > >> drh at sqlite.org > >> ___ > >> sqlite-users mailing list > >> sqlite-users at mailinglists.sqlite.org > >> http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > >> > > ___ > > sqlite-users mailing list > > sqlite-users at mailinglists.sqlite.org > > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > > > > > -- > D. Richard Hipp > drh at sqlite.org > ___ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users >
[sqlite] Testing problem
Is sqllogictest a program which can be downloaded and installed? On Fri, May 8, 2015 at 5:21 PM, Richard Hipp wrote: > On 5/8/15, Sairam Gaddam wrote: > > I have custom SQLite and in order to test it I downl > > oaded sqlite-src-3081000.zip > > (7.29 MiB) as advised, which contains some test files but most of them > are > > .test files and how to execute them? should I use sqllogictest program? > If > > it should be used where is it available? > > The main public SQLite test suite makes extensive use of TCL. > (http://tcl.tk/). On unix or Windows workstations, you simply install > TCL then unpack the SQLite archive, then type "./configure; make test" > on unix or Windows with MinGW/Msys or "nmake /f Makefile.msc test" > under Windows with MSVC. > > If you are on an embedded system that does not have the infrastructure > to support TCL, then you could (as you observe) try to run > sqllogictest, which is written in C. But that test suite is really > only designed to show that SQLite generates the same results as other > database engines for given SQL statements. So it does not test things > like file I/O or transactions or non-universal features such as > partial indexes, common table expression, virtual tables, etc. > > The TH3 test suite is plain C code that provides 100% MC/DC is > designed to run on embedded systems with minimal support > infrastructure. But TH3 is proprietary and is used under license > only. See https://sqlite.org/th3.html for additional information. > > > > > And regarding .c test files some of them require tcl.h file which i could > > not find ! I followed the steps given at the starting of each file but i > > dont find them useful. > > can anyone help me regarding this? > > ___ > > sqlite-users mailing list > > sqlite-users at mailinglists.sqlite.org > > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > > > > > -- > D. Richard Hipp > drh at sqlite.org > ___ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users >
[sqlite] Testing problem
I have custom SQLite and in order to test it I downl oaded sqlite-src-3081000.zip (7.29 MiB) as advised, which contains some test files but most of them are .test files and how to execute them? should I use sqllogictest program? If it should be used where is it available? And regarding .c test files some of them require tcl.h file which i could not find ! I followed the steps given at the starting of each file but i dont find them useful. can anyone help me regarding this?
[sqlite] Regarding testing
Yeah I read that link previously but how do i get all those test cases? On Mon, Apr 27, 2015 at 5:27 PM, Simon Slavin wrote: > > On 27 Apr 2015, at 12:54pm, Sairam Gaddam wrote: > > > How SQLite is tested and can I get those test cases? > > < > http://lmgtfy.com/?q=How+SQLite+is+tested+and+can+I+get+those+test+cases%3F > > > > Simon. > ___ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users >
[sqlite] Regarding testing
How SQLite is tested and can I get those test cases?
[sqlite] Comments in VDBE program
Thanks! Comments are enabled now. On Thu, Apr 16, 2015 at 4:41 PM, Richard Hipp wrote: > On 4/16/15, Sairam Gaddam wrote: > > I am using C SQLite interface. How to enable comments in the VDBE program > > here? > > because they are not enabled by default. > > gcc -DSQLITE -DEBUG filename.c ../sqlite3.c -ldl -lpthread > > I tried with the above line in the terminal but could not succeed in > > enabling the comments. Can any one help me with this? > > I am using Linux 64 bit machine. > > Add -DSQLITE_ENABLE_EXPLAIN_COMMENTS to the compiler command-line. > > > ___ > > sqlite-users mailing list > > sqlite-users at mailinglists.sqlite.org > > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > > > > > -- > D. Richard Hipp > drh at sqlite.org > ___ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users >
[sqlite] Comments in VDBE program
I am using C SQLite interface. How to enable comments in the VDBE program here? because they are not enabled by default. gcc -DSQLITE -DEBUG filename.c ../sqlite3.c -ldl -lpthread I tried with the above line in the terminal but could not succeed in enabling the comments. Can any one help me with this? I am using Linux 64 bit machine.
[sqlite] Regarding SeekGe and Next opcodes in VDBE
Yes sir, I know about " .explain ". Next time I would try that @ Richard Hipp. And thanks Clemens. On Fri, Apr 10, 2015 at 3:57 PM, Clemens Ladisch wrote: > Sairam Gaddam wrote: > > On Thu, Apr 9, 2015 at 1:04 PM, Clemens Ladisch > wrote: > >> Sairam Gaddam wrote: > >>> sql="create table em(name text primary key,age text,pts text);"\ > >>> "create table l(name text primary key,fame text);"; > >>> > >>> sql = "select * from em,l where l.fame=em.age"; > >>> > >>>4 Once 0 130 00 > >>>5 OpenAutoindex230 k(3,nil,nil,nil) 00 > >>>6 Rewind 1 130 00 > >>>7 Column 112 00 > >>>8 Column 103 00 > >>>9 Rowid140 00 > >>> 10 MakeRecord 231 00 > >>> 11 IdxInsert210 10 > >>> 12 Next 170 03 > >>> 13 Column 015 00 > >>> 14 IsNull 5 240 00 > >>> 15 SeekGE 2 245 1 00 > >>> 16 IdxGT2 245 1 00 > >>> 17 Column 006 00 > >>> 18 Copy 570 00 > >>> 19 Column 028 00 > >>> 20 Column 219 00 > >>> 21 Column 20 10 00 > >>> 22 ResultRow650 00 > >>> 23 Next 2 160 00 > >>> 24 Next 040 01 > >>> ... > >>> > >>> whenever the condition in the where clause is false, the program jumps > to > >>> the instruction pointed by p2 of SeekGe > >> > >> Yes. > >> > >>> but if the condition proves to be false for the row 1 of both the > >>> tables, then the program jumps to line 24(in this case) which > >>> corresponds to outer table and takes the second row of outer table > >>> for next iteration, then when will the program fetch 1st row > >>> of table-1 and remaining rows of table-2 ??? > >> > >> In the join loop, this VDBE program does not fetch any rows from the > >> second table: > >> > >> explain query plan select * from em,l where l.fame=em.age; > >> 0|0|0|SCAN TABLE em > >> 0|1|1|SEARCH TABLE l USING AUTOMATIC COVERING INDEX (fame=?) > >> > >> All accesses to "l" are actually handled by the temporary index (which > >> is created by instructions 5..12). One index search is enough to > >> determine whether a fame value exists. > > > > Then why there is a loop (Next opcode at 23rd instruction) over second > > table when it created an index ? > > Because there might be multiple index entries with the same fame value. > > > Regards, > Clemens > ___ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users >
[sqlite] Regarding SeekGe and Next opcodes in VDBE
Then why there is a loop (Next opcode at 23rd instruction) over second table when it created an index ? On Thu, Apr 9, 2015 at 1:04 PM, Clemens Ladisch wrote: > Sairam Gaddam wrote: > > sql="create table em(name text primary key,age text,pts text);"\ > > "create table l(name text primary key,fame text);"; > > > > sql = "select * from em,l where l.fame=em.age"; > > > >4 Once 0 130 00 > >5 OpenAutoindex230 k(3,nil,nil,nil) 00 > >6 Rewind 1 130 00 > >7 Column 112 00 > >8 Column 103 00 > >9 Rowid140 00 > > 10 MakeRecord 231 00 > > 11 IdxInsert210 10 > > 12 Next 170 03 > > 13 Column 015 00 > > 14 IsNull 5 240 00 > > 15 SeekGE 2 245 1 00 > > 16 IdxGT2 245 1 00 > > 17 Column 006 00 > > 18 Copy 570 00 > > 19 Column 028 00 > > 20 Column 219 00 > > 21 Column 20 10 00 > > 22 ResultRow650 00 > > 23 Next 2 160 00 > > 24 Next 040 01 > > ... > > > > whenever the condition in the where clause is false, the program jumps to > > the instruction pointed by p2 of SeekGe > > Yes. > > > but if the condition proves to be false for the row 1 of both the > > tables, then the program jumps to line 24(in this case) which > > corresponds to outer table and takes the second row of outer table > > for next iteration, then when will the program fetch 1st row > > of table-1 and remaining rows of table-2 ??? > > In the join loop, this VDBE program does not fetch any rows from the > second table: > > explain query plan select * from em,l where l.fame=em.age; > 0|0|0|SCAN TABLE em > 0|1|1|SEARCH TABLE l USING AUTOMATIC COVERING INDEX (fame=?) > > All accesses to "l" are actually handled by the temporary index (which > is created by instructions 5..12). One index search is enough to > determine whether a fame value exists. > > > Regards, > Clemens > ___ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users >
[sqlite] Regarding SeekGe and Next opcodes in VDBE
//create table sql="create table em(name text primary key,age text,pts text);"\ "create table l(name text primary key,fame text);"; //insert values sql="insert into em values(44,20,1);"\ "insert into em values(11,20,2);"\ "insert into em values(5,21,3);"\ "insert into l values(11,11);"\ "insert into l values(12,20);"\ "insert into l values(1,20);"; //query sql = "select * from em,l where l.fame=em.age"; Below is a sample VDBE program: 0 Init 0 270 00 1 OpenRead 020 3 00 2 OpenRead 1 150 2 00 3 Rewind 0 250 00 4 Once 0 130 00 5 OpenAutoindex230 k(3,nil,nil,nil) 00 6 Rewind 1 130 00 7 Column 112 00 8 Column 103 00 9 Rowid140 00 10 MakeRecord 231 00 11 IdxInsert210 10 12 Next 170 03 13 Column 015 00 14 IsNull 5 240 00 15 SeekGE 2 245 1 00 16 IdxGT2 245 1 00 17 Column 006 00 18 Copy 570 00 19 Column 028 00 20 Column 219 00 21 Column 20 10 00 22 ResultRow650 00 23 Next 2 160 00 24 Next 040 01 25 Close000 00 26 Halt 000 00 27 Transaction 00 48833 0 01 28 TableLock020 em00 29 TableLock0 150 l 00 30 Goto 010 00 Question: whenever the condition in the where clause is false, the program jumps to the instruction pointed by p2 of SeekGe but if the condition proves to be false for the row 1 of both the tables, then the program jumps to line 24(in this case) which corresponds to outer table and takes the second row of outer table for next iteration, then when will the program fetch 1st row of table-1 and remaining rows of table-2 ???
[sqlite] Clarification regarding Next opcode !
What Next opcode does is advance cursor P1 so that it points to the next
key/data pair in its table or index. If there are no more key/value pairs
then fall through to the following instruction.
But i have a program where i need clarification regarding its operation
(I inserted printf statement in Next opcode which will print next followed
by program counter value - printf("in next %d\n",pc);)
//create table
sql="create table em(name int primary key,age int);"\
"create table idv(id int primary key,name text);"\
"create table l(name int primary key,fame int);";
sql="insert into em values(44,21);"\
"insert into em values(11,20);"\
"insert into em values(5,21);"\
"insert into idv values(11,44);"\
"insert into idv values(44,11);"\
"insert into idv values(5,180);"\
"insert into l values(11,11);"\
"insert into l values(12,20);"\
"insert into l values(1,20);";
sql="select * from l,em,idv where l.fame=em.age";
vdbe:
0 Init 0 330 00
1 OpenRead 0 110 2 00
2 OpenRead 250 2 00
3 OpenRead 120 2 00
4 Rewind 0 300 00
5 Rewind 2 290 00
6 Once 0 150 00
7 OpenAutoindex330 k(3,nil,nil,nil) 00
8 Rewind 1 150 00
9 Column 112 00
10 Column 103 00
11 Rowid140 00
12 MakeRecord 231 00
13 IdxInsert310 10
14 Next 190 03
15 Column 015 00
16 IsNull 5 280 00
17 Affinity 510 D 00
18 SeekGE 3 285 1 00
19 IdxGT3 285 1 00
20 Column 006 00
21 Column 017 00
22 Column 318 00
23 Column 309 00
24 Column 20 10 00
25 Column 21 11 00
26 ResultRow660 00
27 Next 3 190 00
28 Next 260 01
29 Next 050 01
30 Close000 00
31 Close200 00
32 Halt 000 00
33 Transaction 00 45819 0 01
34 TableLock0 110 l 00
35 TableLock050 idv 00
36 TableLock020 em00
37 Goto 010 00
result:
in next 14
in next 14
in next 14
in next 28
in next 28
in next 28
in next 29
12,20,11,20,11,44.
in next 27
in next 28
12,20,11,20,44,11.
in next 27
in next 28
12,20,11,20,5,180.
in next 27
in next 28
in next 29
1,20,11,20,11,44.
in next 27
in next 28
1,20,11,20,44,11.
in next 27
in next 28
1,20,11,20,5,180.
in next 27
in next 28
in next 29
Here i dont know the behaviour of Next opcode at 27 because whenever it
comes to that opcode it goes to Next opcode at 28.
[sqlite] regarding loops in vdbe code
0 000 NULL > 10Transaction1 0 000 NULL > 11VerifyCookie 1 1 000 NULL > 12TableLock 1 2 0 a 00 NULL > 13Goto 0 3 000 NULL > > explain select * from a join b on a.rowid=b.a_rowid where b.f2 = 1; > addr opcode p1p2p3p4 p5 comment > - - -- - > 0 Trace 0 0 000 NULL > 1 Integer1 1 000 NULL > 2 Goto 0 19000 NULL > 3 OpenRead 1 3 1 2 00 b > 4 OpenRead 0 2 1 1 00 a > 5 Rewind 1 16000 NULL > 6 Column 1 1 200 b.f2 > 7 Ne 1 152 collseq(BINARY) 6c NULL > 8 Column 1 0 300 b.a_rowid > 9 MustBeInt 3 15000 NULL > 10NotExists 0 15300 pk > 11Column 0 0 400 a.f1 > 12Column 1 0 500 b.a_rowid > 13Column 1 1 600 b.f2 > 14ResultRow 4 3 000 NULL > 15Next 1 6 001 NULL > 16Close 1 0 000 NULL > 17Close 0 0 000 NULL > 18Halt 0 0 000 NULL > 19Transaction1 0 0 00 NULL > 20VerifyCookie 1 2 000 NULL > 21TableLock 1 3 0 b 00 NULL > 22TableLock 1 2 0 a 00 NULL > 23Goto 0 3 000 NULL > > -Urspr?ngliche Nachricht- > Von: Sairam Gaddam [mailto:gaddamsairam at gmail.com] > Gesendet: Dienstag, 17. M?rz 2015 12:26 > An: General Discussion of SQLite Database > Betreff: [sqlite] regarding loops in vdbe code > > When joining a table in sqlite with some condition using where clause, > sqlite sometimes generate less number of loops(Next opcodes) than the > number of tables. > Can anyone explain how sqlite iterates through all the tables when it has > less number of loops. > ___ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > > > ___ > Gunter Hick > Software Engineer > Scientific Games International GmbH > FN 157284 a, HG Wien > Klitschgasse 2-4, A-1130 Vienna, Austria > Tel: +43 1 80100 0 > E-Mail: hick at scigames.at > > This communication (including any attachments) is intended for the use of > the intended recipient(s) only and may contain information that is > confidential, privileged or legally protected. Any unauthorized use or > dissemination of this communication is strictly prohibited. If you have > received this communication in error, please immediately notify the sender > by return e-mail message and delete all copies of the original > communication. Thank you for your cooperation. > > > ___ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users >
[sqlite] regarding loops in vdbe code
When joining a table in sqlite with some condition using where clause, sqlite sometimes generate less number of loops(Next opcodes) than the number of tables. Can anyone explain how sqlite iterates through all the tables when it has less number of loops.
[sqlite] regarding loops in joins(VDBE)
I am trying to understand how sqlite joins execute and this is just a simple example. Can you please elaborate a bit on the index look up part ? How is sqlite navigating the cursor to point to the rows of other table with out a loop ? How does index look up work without looping as indexes are also represented by cursor ? On Mon, Mar 9, 2015 at 4:37 PM, Hick Gunter wrote: > Are you trying to create tables with INTEGER PRIMARY KEY? You have to > write EXACTLY "integer primary key" (not case specific) to achieve this. > The em <=> lo join would probably profit from this. > > Your join specifies to compare em.name (a column with numeric affinity) > to idv.name (a column with text affinity); this will force SQLite to > convert one of the fields for the conversion. Is this what you intended? > > Maybe you should try to "EXPLAIN QUERY PLAN" to find out what SQLite plans > to do. > > From a quick look at the VDBE code it is clearly choosing to scan your em > table and access the lo and idv tables via index lookup. If either of the > index lookups were not UNIQUE, there would be an inner loop to resolve the > join. > > Since em.name and lo.name are matching primary keys, why the two tables? > Which other entity has a lo(cation)? And how are you going to keep that > other entity from assigning conflicting keys (i.e. those already used for > em entries)? > > Are you sure the em(ployee)'s name is an integer? > > -Urspr?ngliche Nachricht- > Von: Sairam Gaddam [mailto:gaddamsairam at gmail.com] > Gesendet: Montag, 09. M?rz 2015 11:40 > An: General Discussion of SQLite Database > Betreff: [sqlite] regarding loops in joins(VDBE) > > sir, > I have a join query with 3 tables and 2 conditions in the where > clause.But the program executes by opening single loop.Can any one know how > is executes? > > I have included the query and the vdbe program in the link below: > http://pastebin.com/aA3QSJ7w > ___ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > > > ___ > Gunter Hick > Software Engineer > Scientific Games International GmbH > FN 157284 a, HG Wien > Klitschgasse 2-4, A-1130 Vienna, Austria > Tel: +43 1 80100 0 > E-Mail: hick at scigames.at > > This communication (including any attachments) is intended for the use of > the intended recipient(s) only and may contain information that is > confidential, privileged or legally protected. Any unauthorized use or > dissemination of this communication is strictly prohibited. If you have > received this communication in error, please immediately notify the sender > by return e-mail message and delete all copies of the original > communication. Thank you for your cooperation. > > > ___ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users >
[sqlite] regarding loops in joins(VDBE)
sir, I have a join query with 3 tables and 2 conditions in the where clause.But the program executes by opening single loop.Can any one know how is executes? I have included the query and the vdbe program in the link below: http://pastebin.com/aA3QSJ7w
[sqlite] Regarding creating a mem object and copying contents to it in SQLite
Yaa we work together and we need some assistance regarding that. On Wed, Feb 25, 2015 at 1:18 PM, Hick Gunter wrote: > Maybe you would like to exchange experiences with Prakash Premkumar < > prakash.prax at gmail.com> about hacking SQLite internals. > > -Urspr?ngliche Nachricht----- > Von: Sairam Gaddam [mailto:gaddamsairam at gmail.com] > Gesendet: Mittwoch, 25. Februar 2015 08:23 > An: General Discussion of SQLite Database > Betreff: Re: [sqlite] Regarding creating a mem object and copying contents > to it in SQLite > > I am trying to optimize certain operations of SQLite internally, so i > created mem object. > > On Wed, Feb 25, 2015 at 12:36 PM, Hick Gunter wrote: > > > The mem object is internal to sqlite, it is not intended to be > > created/changed by user code. > > > > What are you trying to do that makes you think you need to manipulate > > internal structures? > > > > -Urspr?ngliche Nachricht- > > Von: Sairam Gaddam [mailto:gaddamsairam at gmail.com] > > Gesendet: Mittwoch, 25. Februar 2015 07:41 > > An: sqlite-users at sqlite.org > > Betreff: [sqlite] Regarding creating a mem object and copying contents > > to it in SQLite > > > > hello, > > I created a mem object in SQLite and copied a string value to > > its member and i initialized some other members to default values > > manually, it worked well but some times it shows realloc() error. > > I also found a function sqlite3VdbeMemSetStr() which will > > copy the string value into new mem but even it fails sometimes. > > So what is the correct way of creating a mem object and > > copying a string to its member so that SQLite will work > fruitfully.Anyone know??? > > ___ > > sqlite-users mailing list > > sqlite-users at mailinglists.sqlite.org > > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > > > > > > ___ > > Gunter Hick > > Software Engineer > > Scientific Games International GmbH > > FN 157284 a, HG Wien > > Klitschgasse 2-4, A-1130 Vienna, Austria > > Tel: +43 1 80100 0 > > E-Mail: hick at scigames.at > > > > This communication (including any attachments) is intended for the use > > of the intended recipient(s) only and may contain information that is > > confidential, privileged or legally protected. Any unauthorized use or > > dissemination of this communication is strictly prohibited. If you > > have received this communication in error, please immediately notify > > the sender by return e-mail message and delete all copies of the > > original communication. Thank you for your cooperation. > > > > > > ___ > > sqlite-users mailing list > > sqlite-users at mailinglists.sqlite.org > > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > > > ___ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > > > ___ > Gunter Hick > Software Engineer > Scientific Games International GmbH > FN 157284 a, HG Wien > Klitschgasse 2-4, A-1130 Vienna, Austria > Tel: +43 1 80100 0 > E-Mail: hick at scigames.at > > This communication (including any attachments) is intended for the use of > the intended recipient(s) only and may contain information that is > confidential, privileged or legally protected. Any unauthorized use or > dissemination of this communication is strictly prohibited. If you have > received this communication in error, please immediately notify the sender > by return e-mail message and delete all copies of the original > communication. Thank you for your cooperation. > > > ___ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users >
[sqlite] Regarding creating a mem object and copying contents to it in SQLite
I am trying to optimize certain operations of SQLite internally, so i created mem object. On Wed, Feb 25, 2015 at 12:36 PM, Hick Gunter wrote: > The mem object is internal to sqlite, it is not intended to be > created/changed by user code. > > What are you trying to do that makes you think you need to manipulate > internal structures? > > -Urspr?ngliche Nachricht- > Von: Sairam Gaddam [mailto:gaddamsairam at gmail.com] > Gesendet: Mittwoch, 25. Februar 2015 07:41 > An: sqlite-users at sqlite.org > Betreff: [sqlite] Regarding creating a mem object and copying contents to > it in SQLite > > hello, > I created a mem object in SQLite and copied a string value to its > member and i initialized some other members to default values manually, it > worked well but some times it shows realloc() error. > I also found a function sqlite3VdbeMemSetStr() which will copy > the string value into new mem but even it fails sometimes. > So what is the correct way of creating a mem object and copying a > string to its member so that SQLite will work fruitfully.Anyone know??? > ___ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > > > ___ > Gunter Hick > Software Engineer > Scientific Games International GmbH > FN 157284 a, HG Wien > Klitschgasse 2-4, A-1130 Vienna, Austria > Tel: +43 1 80100 0 > E-Mail: hick at scigames.at > > This communication (including any attachments) is intended for the use of > the intended recipient(s) only and may contain information that is > confidential, privileged or legally protected. Any unauthorized use or > dissemination of this communication is strictly prohibited. If you have > received this communication in error, please immediately notify the sender > by return e-mail message and delete all copies of the original > communication. Thank you for your cooperation. > > > ___ > sqlite-users mailing list > sqlite-users at mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users >
[sqlite] Regarding creating a mem object and copying contents to it in SQLite
hello, I created a mem object in SQLite and copied a string value to its member and i initialized some other members to default values manually, it worked well but some times it shows realloc() error. I also found a function sqlite3VdbeMemSetStr() which will copy the string value into new mem but even it fails sometimes. So what is the correct way of creating a mem object and copying a string to its member so that SQLite will work fruitfully.Anyone know???
[sqlite] regarding looping in vdbe for sqlite table joins!
Normally for executing joins in sqlite,the vdbe program opens 1 loop for each and every table but in my code(attached that file via pastebin) ,i am facing an issue because it is opening only 2 loops even if i use 4 tables in joining operation. can anyone explain why it happened like that and loops for which tables got opened? code : http://pastebin.com/PHV4K4Hh ___ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
[sqlite] regarding sqlite3_prepare_v2() func
I have one doubt regarding sqlite code.
I have 2 programs-one with sqlite3_exec() included in the code and in other
it is not included.I included those files which are zmain.c and zmain1.c
respectively.
First i created a database and added a table "em" and added some contents
to it,then i executed and prepared the sqlite select query.
I added "printf("result");" in the "case op_resultrow" of the function
sqlite3vdbeexec().
Here when i executed zmain.c,
sqlite3_prepare_v2(db, sql, strlen(sql) + 1, , NULL);
the above statement didn't print anything.
OUTPUT:
database opened successfully
result
result
result
result
Operation done successfully
Before
Afterprep
(clearly there is nothing between before and afterprep)
But when i commented the sqlite3_exec() in zmain1.c
due to sqlite_prepare_v2() function,the program somehow entered
sqlite3vdbeexec() and printed what i gave in my printf statement.
OUTPUT:
database opened successfully
Operation done successfully
Before
result
result
Afterprep
(clearly there are some output between before and afterprep)
My doubt is why the function call sqlite3_prepare_v2() called
sqlite3vdbeexec in second case and why not in first program.
zmain.c :- http://pastebin.com/ggmw9VTE
zmain1.c :- http://pastebin.com/xbgVLAyL
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[sqlite] regarding sqlite3_prepare_v2() func
I have one doubt regarding sqlite code.
I have 2 programs-one with sqlite3_exec() included in the code and in other
it is not included.I included those files which are zmain.c and zmain1.c
respectively.
First i created a database and added a table "em" and added some contents
to it,then i executed and prepared the sqlite select query.
I added "printf("result");" in the "case op_resultrow" of the function
sqlite3vdbeexec().
Here when i executed zmain.c,
sqlite3_prepare_v2(db, sql, strlen(sql) + 1, , NULL);
the above statement didn't print anything.
OUTPUT:
database opened successfully
result
result
result
result
Operation done successfully
Before
Afterprep
(clearly there is nothing between before and afterprep)
But when i commented the sqlite3_exec() in zmain1.c
due to sqlite_prepare_v2() function,the program somehow entered
sqlite3vdbeexec() and printed what i gave in my printf statement.
OUTPUT:
database opened successfully
Operation done successfully
Before
result
result
Afterprep
(clearly there are some output between before and afterprep)
My doubt is why the function call sqlite3_prepare_v2() called
sqlite3vdbeexec in second case and why not in first program.
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sqlite-users@sqlite.org
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