Re: [libdbi-users] libdbi transaction support
On 26/01/13 8:30 PM, markus.hoeni...@mhoenicka.de wrote: > Toby Thain writes: > > Yes, you just found out the hard way that it's wise to include ENGINE > > specifications in MySQL CREATE TABLE's. > > > > True indeed. Actually I think the news is even worse: I seem to recall that MySQL can even *ignore* ENGINE specifications if the engine isn't installed. Leaving you, again, with MyISAM-the-inadequate. More silent fail. I think I've wasted some time on that one in the past. --Toby > > regards, > Markus > -- Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft MVPs and experts. ON SALE this month only -- learn more at: http://p.sf.net/sfu/learnnow-d2d ___ libdbi-users mailing list libdbi-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libdbi-users
Re: [libdbi-users] libdbi transaction support
Toby Thain writes: > Yes, you just found out the hard way that it's wise to include ENGINE > specifications in MySQL CREATE TABLE's. > True indeed. The problem with MySQL's storage engines is that the transaction_support and savepoint_support driver capabilities cannot be relied upon because they depend on a couple of factors - how the database server was compiled and configured, how particular tables were created and so on. The driver caps may get things wrong in quite a few cases. BTW I've finished updating the test kit which should now cover all aspects of transactions and savepoints as well. I'd greatly appreciate if everyone could give the current cvs revisions a try and report success and failures. regards, Markus -- Markus Hoenicka http://www.mhoenicka.de AQ score 38 -- Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft MVPs and experts. ON SALE this month only -- learn more at: http://p.sf.net/sfu/learnnow-d2d ___ libdbi-users mailing list libdbi-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libdbi-users
Re: [libdbi-users] libdbi transaction support
On 25/01/13 7:40 PM, markus.hoeni...@mhoenicka.de wrote: > Markus Hoenicka writes: > > Another possible reason for problems is the table type. If someone > > uses MyISAM tables, the result I got would be expected. However, MySQL > > uses InnoDB tables as default these days, and I double-checked that > > they were used in my tests. > > Turns out that InnoDB is the default engine only in versions 5.5.5 and > later. On my box, MyISAM tables were created by default. The test Yes, you just found out the hard way that it's wise to include ENGINE specifications in MySQL CREATE TABLE's. They took far too long to change the default engine to InnoDB. --Toby > correctly found out that the latter don't support transactions :-( > > I've changed the CREATE TABLE statement on my box to ask for InnoDB > tables instead. This eliminates the failure of the rollback test. > > I'll try and finish the test suite asap. The transaction tests require > some polish as they should run only if the driver supports > transactions. > > regards, > Markus > -- Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft MVPs and experts. ON SALE this month only -- learn more at: http://p.sf.net/sfu/learnnow-d2d ___ libdbi-users mailing list libdbi-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libdbi-users
Re: [libdbi-users] libdbi transaction support
Markus Hoenicka writes: > Another possible reason for problems is the table type. If someone > uses MyISAM tables, the result I got would be expected. However, MySQL > uses InnoDB tables as default these days, and I double-checked that > they were used in my tests. Turns out that InnoDB is the default engine only in versions 5.5.5 and later. On my box, MyISAM tables were created by default. The test correctly found out that the latter don't support transactions :-( I've changed the CREATE TABLE statement on my box to ask for InnoDB tables instead. This eliminates the failure of the rollback test. I'll try and finish the test suite asap. The transaction tests require some polish as they should run only if the driver supports transactions. regards, Markus -- Markus Hoenicka http://www.mhoenicka.de AQ score 38 -- Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft MVPs and experts. ON SALE this month only -- learn more at: http://p.sf.net/sfu/learnnow-d2d ___ libdbi-users mailing list libdbi-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libdbi-users
Re: [libdbi-users] libdbi transaction support
Rainer Gerhards was heard to say: > we have given it a try today and things look pretty good :-). Sounds good :-) > Unfortunately, we can reproduce the problem with MySQL. I barely > remember that MySQL by default has implicit commits enabled, what > needs to be turned off if you need real ones. > As Olivier already mentioned, any eplicit START TRANSACTION overrides autocommit, so this shouldn't interfere here. Even if an application using libdbi turns autocommit off or on deliberately, START TRANSACTION should still work as expected. Another possible reason for problems is the table type. If someone uses MyISAM tables, the result I got would be expected. However, MySQL uses InnoDB tables as default these days, and I double-checked that they were used in my tests. I'll try to test the pgsql driver on the weekend to see if that causes problems too. I'll also check the MySQL logs to see if I find something weird, and I'll run some transactions in MySQL's plain ol' command line interface just to make sure it isn't MySQL playing tricks on us. regards, Markus -- Markus Hoenicka http://www.mhoenicka.de AQ score 38 -- Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft MVPs and experts. ON SALE this month only -- learn more at: http://p.sf.net/sfu/learnnow-d2d ___ libdbi-users mailing list libdbi-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libdbi-users
Re: [libdbi-users] libdbi transaction support
Hello, > we have given it a try today and things look pretty good :-). Unfortunately, > we can reproduce the problem with MySQL. I barely remember that MySQL by > default has implicit commits enabled, what needs to be turned off if you need > real ones. By default, MySQL has autocommit enabled. This is disabled automatically when you issue "START TRANSACTION" statement (or changed default behaviour in MySQL config file). See http://dev.mysql.com/doc/refman/5.5/en/commit.html Olivier -- Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft MVPs and experts. ON SALE this month only -- learn more at: http://p.sf.net/sfu/learnnow-d2d ___ libdbi-users mailing list libdbi-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libdbi-users
Re: [libdbi-users] libdbi transaction support
> I've checked in new versions of libdbi/src/dbi_main.c containing the > implementations of the transaction functions and libdbi- > drivers/tests/test_dbi.c with a first shot at the required test functions. > MySQL seems to fail to rollback transactions on my box whereas SQLite3 > succeeds. I'm too tired now to track this down, maybe someone else can > have a look at this too. I hope I'll get back to this on the weekend. Hi Markus, we have given it a try today and things look pretty good :-). Unfortunately, we can reproduce the problem with MySQL. I barely remember that MySQL by default has implicit commits enabled, what needs to be turned off if you need real ones. At least I have check the tx support in our native mysql driver that Ulrike did and there is this call. Maybe it's useful for you: http://git.adiscon.com/?p=rsyslog.git;a=blob;f=plugins/ommysql/ommysql.c;h=2dfa29de74bd4b172ea6073bb970759753ace491;hb=HEAD#l223 Thanks again for your help! Rainer -- Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft MVPs and experts. ON SALE this month only -- learn more at: http://p.sf.net/sfu/learnnow-d2d ___ libdbi-users mailing list libdbi-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libdbi-users
Re: [libdbi-users] libdbi transaction support
Rainer Gerhards writes: > > Zitat von Rainer Gerhards : > > > > > sorry for the long silence, we got sidetracked ourselfs. Finally, we > > > yesterday tried to write some test programs to get started. To do so, > > > I did a cvs checkout for both libdbi and libdbi-drivers (according to > > > instructions on the site). I can see the new transaction functions > > > inside the sgml files as well as the headers. > > > However, I do not find any implementation (.c files). > > > > > > Am I overlooking something? > > > > > > > No. Apparently my bad. I'll fix that tonight. > > Thanks a lot! > Rainer I've checked in new versions of libdbi/src/dbi_main.c containing the implementations of the transaction functions and libdbi-drivers/tests/test_dbi.c with a first shot at the required test functions. MySQL seems to fail to rollback transactions on my box whereas SQLite3 succeeds. I'm too tired now to track this down, maybe someone else can have a look at this too. I hope I'll get back to this on the weekend. regards, Markus -- Markus Hoenicka http://www.mhoenicka.de AQ score 38 -- Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft MVPs and experts. ON SALE this month only -- learn more at: http://p.sf.net/sfu/learnnow-d2d ___ libdbi-users mailing list libdbi-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libdbi-users
Re: [libdbi-users] libdbi transaction support
> Rainer Gerhards writes: > > > This should be easy to retrofit. I'lls see if I find > > some time but > feel > free to beat me at it. > > > > I am quite busy myself at the moment, but I could try and see if I > could > craft something along that path... > > > > Hi all, > > I've stolen some time from myself to provide a first shot at transaction and > savepoint support, see the current cvs revisions of libdbi and libdbi-drivers. > The code is entirely untested except that the drivers which I use myself > compile and don't crash upon loading. I didn't get round to adding the > documentation and the tests, but feel free to test the current code yourself. > Usage should be pretty obvious if you look at the diffs. I'm sure some rough > edges remain, but then... it's a start. Hi Markus, sorry for the long silence, we got sidetracked ourselfs. Finally, we yesterday tried to write some test programs to get started. To do so, I did a cvs checkout for both libdbi and libdbi-drivers (according to instructions on the site). I can see the new transaction functions inside the sgml files as well as the headers. However, I do not find any implementation (.c files). Am I overlooking something? Rainer -- Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft MVPs and experts. ON SALE this month only -- learn more at: http://p.sf.net/sfu/learnnow-d2d ___ libdbi-users mailing list libdbi-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libdbi-users
Re: [libdbi-users] libdbi transaction support
> Zitat von Rainer Gerhards : > > > sorry for the long silence, we got sidetracked ourselfs. Finally, we > > yesterday tried to write some test programs to get started. To do so, > > I did a cvs checkout for both libdbi and libdbi-drivers (according to > > instructions on the site). I can see the new transaction functions > > inside the sgml files as well as the headers. > > However, I do not find any implementation (.c files). > > > > Am I overlooking something? > > > > No. Apparently my bad. I'll fix that tonight. Thanks a lot! Rainer -- Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft MVPs and experts. ON SALE this month only -- learn more at: http://p.sf.net/sfu/learnnow-d2d ___ libdbi-users mailing list libdbi-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libdbi-users
Re: [libdbi-users] libdbi transaction support
Zitat von Rainer Gerhards : > sorry for the long silence, we got sidetracked ourselfs. Finally, we > yesterday tried to write some test programs to get started. To do > so, I did a cvs checkout for both libdbi and libdbi-drivers > (according to instructions on the site). I can see the new > transaction functions inside the sgml files as well as the headers. > However, I do not find any implementation (.c files). > > Am I overlooking something? > No. Apparently my bad. I'll fix that tonight. regards, Markus -- Markus Hoenicka http://www.mhoenicka.de AQ score 38 -- Master Visual Studio, SharePoint, SQL, ASP.NET, C# 2012, HTML5, CSS, MVC, Windows 8 Apps, JavaScript and much more. Keep your skills current with LearnDevNow - 3,200 step-by-step video tutorials by Microsoft MVPs and experts. ON SALE this month only -- learn more at: http://p.sf.net/sfu/learnnow-d2d ___ libdbi-users mailing list libdbi-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libdbi-users
Re: [libdbi-users] libdbi transaction support
markus.hoeni...@mhoenicka.de writes: > I've stolen some time from myself to provide a first shot at > transaction and savepoint support, see the current cvs revisions of > libdbi and libdbi-drivers. The code is entirely untested except that > the drivers which I use myself compile and don't crash upon loading. I > didn't get round to adding the documentation and the tests, but feel > free to test the current code yourself. Usage should be pretty obvious > if you look at the diffs. I'm sure some rough edges remain, but > then... it's a start. > FYI I've also updated the docs in cvs to reflect the latest changes. regards, Markus -- Markus Hoenicka http://www.mhoenicka.de AQ score 38 -- LogMeIn Rescue: Anywhere, Anytime Remote support for IT. Free Trial Remotely access PCs and mobile devices and provide instant support Improve your efficiency, and focus on delivering more value-add services Discover what IT Professionals Know. Rescue delivers http://p.sf.net/sfu/logmein_12329d2d ___ libdbi-users mailing list libdbi-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libdbi-users
Re: [libdbi-users] libdbi transaction support
Rainer Gerhards writes: > > This should be easy to retrofit. I'lls see if I find > > some time but feel free to beat me at it. > > I am quite busy myself at the moment, but I could try and see if I > could craft something along that path... > Hi all, I've stolen some time from myself to provide a first shot at transaction and savepoint support, see the current cvs revisions of libdbi and libdbi-drivers. The code is entirely untested except that the drivers which I use myself compile and don't crash upon loading. I didn't get round to adding the documentation and the tests, but feel free to test the current code yourself. Usage should be pretty obvious if you look at the diffs. I'm sure some rough edges remain, but then... it's a start. regards, Markus -- Markus Hoenicka http://www.mhoenicka.de AQ score 38 -- Keep yourself connected to Go Parallel: BUILD Helping you discover the best ways to construct your parallel projects. http://goparallel.sourceforge.net ___ libdbi-users mailing list libdbi-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libdbi-users
Re: [libdbi-users] libdbi transaction support
On 20/11/12 11:50 AM, Markus Hoenicka wrote: > Mike Rylander was heard to say: > >> I think I'd add three calls to the proposed API, though, for support >> of savepoints. They're part of the SQL standard, and supported by >> several SQL RDBMS' including Postgres (the db my project uses, and we >> use libdbi to connect to PG). The relevant PG documentation is >> available at http://www.postgresql.org/docs/9.1/static/sql-savepoint.html >> . I have wrappers for savepoints in my implementation, and they are >> very handy for complex DB interactions. >> > > Sounds like a no-brainer if it is as simple as you say. I don't keep > the SQL standard underneath my pillow, but is it safe to assume that > database engines are responsible to deal with any pending savepoints > if a transaction is committed (i.e. no extra work for libdbi)? > > This brings up another question. Applications should of course check > the "transaction_supported" and "savepoints_supported" driver > capabilities and act responsibly. But if a database engine does not > support savepoints, or transactions altogether, should libdbi just go > ahead when asked, or should it throw an error instead? I recall that > MySQL "supported" transactions in MyISAM tables using no-ops. That is correct. The transactional engine is InnoDB, and it's the recommended one if you care about your data and its integrity. I would suggest that libdbi should not try to be clever here - it's basically infeasible to try and determine whether a sequence of statements is transactionally unsafe in some way. For one thing, storage engines can be mixed in one MySQL schema, and a sequence of statements can involve them in arbitrary combinations (which is very foolish, but still). A warning about MyISAM might be placed in the manual, however. I don't know anything about savepoints so can't comment on that part. --Toby > > regards, > Markus > -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ libdbi-users mailing list libdbi-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libdbi-users
Re: [libdbi-users] libdbi transaction support
Mike Rylander was heard to say: > I think I'd add three calls to the proposed API, though, for support > of savepoints. They're part of the SQL standard, and supported by > several SQL RDBMS' including Postgres (the db my project uses, and we > use libdbi to connect to PG). The relevant PG documentation is > available at http://www.postgresql.org/docs/9.1/static/sql-savepoint.html > . I have wrappers for savepoints in my implementation, and they are > very handy for complex DB interactions. > Sounds like a no-brainer if it is as simple as you say. I don't keep the SQL standard underneath my pillow, but is it safe to assume that database engines are responsible to deal with any pending savepoints if a transaction is committed (i.e. no extra work for libdbi)? This brings up another question. Applications should of course check the "transaction_supported" and "savepoints_supported" driver capabilities and act responsibly. But if a database engine does not support savepoints, or transactions altogether, should libdbi just go ahead when asked, or should it throw an error instead? I recall that MySQL "supported" transactions in MyISAM tables using no-ops. regards, Markus -- Markus Hoenicka http://www.mhoenicka.de AQ score 38 -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ libdbi-users mailing list libdbi-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libdbi-users
Re: [libdbi-users] libdbi transaction support
On Tue, Nov 20, 2012 at 7:59 AM, Rainer Gerhards wrote: > On Tue, Nov 20, 2012 at 1:02 PM, Markus Hoenicka > wrote: >> In fact, we already have a (not well documented) infrastructure for things >> like this in place. Every driver keeps a list of boolean "capabilities" >> which is merely a key-value list of whatever we think is useful or >> necessary. To date, only the "safe_dlclose" capability seems to be used, see >> e.g. dbd_initialize in libdbi-drivers/drivers/mysql/dbd_mysql.c. There is an >> internal function _dbd_register_driver_cap() which can be used by the >> drivers to announce a capability. And there is a public function >> dbi_driver_cap_get() which allows applications to query the list of >> capabilities at runtime. So all we'd have to do is modify the drivers and >> have them add a "transaction_support" capability set to 1 for those who >> support transactions. > > ok, that makes sense and is excellent to have! > >>> For TX support, I'd expect calls for >>> >>> - begin transaction >>> - commit >>> - rollback >>> >>> that's it, so all in all 4 calls. Would you agree to that? >> First, I'm glad to so movement on this! The code in the project I'm involved with handles transactions on its own already using something along the lines of the wrapper pattern Markus mentioned, so it won't make a big difference to me immediately, but having a sanctioned API is almost always better, IMO. I think I'd add three calls to the proposed API, though, for support of savepoints. They're part of the SQL standard, and supported by several SQL RDBMS' including Postgres (the db my project uses, and we use libdbi to connect to PG). The relevant PG documentation is available at http://www.postgresql.org/docs/9.1/static/sql-savepoint.html . I have wrappers for savepoints in my implementation, and they are very handy for complex DB interactions. I can't offer many properly shaped tuits toward the development effort right now, but supporting savepoints should amount to essentially adding cut-and-paste duplicates of begin, commit and rollback. Would it be objectionable to ask for savepoint support to piggy-back on transaction support? -- Mike Rylander | Director of Research and Development | Equinox Software, Inc. / Your Library's Guide to Open Source | phone: 1-877-OPEN-ILS (673-6457) | email: mi...@esilibrary.com | web: http://www.esilibrary.com -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ libdbi-users mailing list libdbi-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libdbi-users
Re: [libdbi-users] libdbi transaction support
On Tue, Nov 20, 2012 at 1:02 PM, Markus Hoenicka wrote: > In fact, we already have a (not well documented) infrastructure for things > like this in place. Every driver keeps a list of boolean "capabilities" > which is merely a key-value list of whatever we think is useful or > necessary. To date, only the "safe_dlclose" capability seems to be used, see > e.g. dbd_initialize in libdbi-drivers/drivers/mysql/dbd_mysql.c. There is an > internal function _dbd_register_driver_cap() which can be used by the > drivers to announce a capability. And there is a public function > dbi_driver_cap_get() which allows applications to query the list of > capabilities at runtime. So all we'd have to do is modify the drivers and > have them add a "transaction_support" capability set to 1 for those who > support transactions. ok, that makes sense and is excellent to have! >> For TX support, I'd expect calls for >> >> - begin transaction >> - commit >> - rollback >> >> that's it, so all in all 4 calls. Would you agree to that? > > > yes, except that we don't need the drvrTXSupport() function as we can use > dbi_driver_cap_get() instead. I'll see if I can dig a bit into the code within the next couple of days. Thanks! Rainer -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ libdbi-users mailing list libdbi-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libdbi-users
Re: [libdbi-users] libdbi transaction support
Rainer Gerhards was heard to say: > That's what I would expect. However, I think it would be useful to > have a call like "drvrTXSupport()" returning 1 if the driver supports > transaction and 0 otherwise. That way, an app could either fall back > to non-transcation mode OR tell the user that the database system is > not suitable for that kind of application. That would probably also > provide a smooth migration path, were only the primary TX interface > needs to be implemented and drivers can be upgraded as time permits > (assuming that some drivers are maintained by external entities). In fact, we already have a (not well documented) infrastructure for things like this in place. Every driver keeps a list of boolean "capabilities" which is merely a key-value list of whatever we think is useful or necessary. To date, only the "safe_dlclose" capability seems to be used, see e.g. dbd_initialize in libdbi-drivers/drivers/mysql/dbd_mysql.c. There is an internal function _dbd_register_driver_cap() which can be used by the drivers to announce a capability. And there is a public function dbi_driver_cap_get() which allows applications to query the list of capabilities at runtime. So all we'd have to do is modify the drivers and have them add a "transaction_support" capability set to 1 for those who support transactions. > > For TX support, I'd expect calls for > > - begin transaction > - commit > - rollback > > that's it, so all in all 4 calls. Would you agree to that? yes, except that we don't need the drvrTXSupport() function as we can use dbi_driver_cap_get() instead. > >> This should be easy to retrofit. I'lls see if I find >> some time but feel free to beat me at it. > > I am quite busy myself at the moment, but I could try and see if I > could craft something along that path... > > Rainer regards, Markus -- Markus Hoenicka http://www.mhoenicka.de AQ score 38 -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ libdbi-users mailing list libdbi-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libdbi-users
Re: [libdbi-users] libdbi transaction support
On Tue, Nov 20, 2012 at 11:51 AM, Markus Hoenicka wrote: > not exceptionally dumb, but rather touching a sensitive issue. I've > used simple wrappers in one of my applications that could easily be > moved into libdbi. I think a transaction interface has been missing > from libdbi because some database engines that were supported in the > days of yore did not have transaction support. Ah! At least this explains. > I think most database > engines which are supported or have experimental support these days > support transactions by sending queries along the lines of "begin" or > "begin work" etc. That's what I would expect. However, I think it would be useful to have a call like "drvrTXSupport()" returning 1 if the driver supports transaction and 0 otherwise. That way, an app could either fall back to non-transcation mode OR tell the user that the database system is not suitable for that kind of application. That would probably also provide a smooth migration path, were only the primary TX interface needs to be implemented and drivers can be upgraded as time permits (assuming that some drivers are maintained by external entities). For TX support, I'd expect calls for - begin transaction - commit - rollback that's it, so all in all 4 calls. Would you agree to that? > This should be easy to retrofit. I'lls see if I find > some time but feel free to beat me at it. I am quite busy myself at the moment, but I could try and see if I could craft something along that path... Rainer -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ libdbi-users mailing list libdbi-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libdbi-users
Re: [libdbi-users] libdbi transaction support
Rainer Gerhards was heard to say: > Hi all, > > sorry if this is an exceptionally dumb question, but: does libdbi > support transactions (and, if so, via which functions)? I tried to > find the transaction support functions, but did not come up with > anything. Also a (granted, quick) look at the source did not tell me > anything. > > Any help is deeply appreciated, > Rainer > Hi, not exceptionally dumb, but rather touching a sensitive issue. I've used simple wrappers in one of my applications that could easily be moved into libdbi. I think a transaction interface has been missing from libdbi because some database engines that were supported in the days of yore did not have transaction support. I think most database engines which are supported or have experimental support these days support transactions by sending queries along the lines of "begin" or "begin work" etc. This should be easy to retrofit. I'lls see if I find some time but feel free to beat me at it. regards, Markus -- Markus Hoenicka http://www.mhoenicka.de AQ score 38 -- Monitor your physical, virtual and cloud infrastructure from a single web console. Get in-depth insight into apps, servers, databases, vmware, SAP, cloud infrastructure, etc. Download 30-day Free Trial. Pricing starts from $795 for 25 servers or applications! http://p.sf.net/sfu/zoho_dev2dev_nov ___ libdbi-users mailing list libdbi-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libdbi-users
