[firebird-support] Re: Unable to create unique constraint
André wrote ... The table is a completely new creation, and nobody else could have been using it besides me, although the database itself is the original production database used by some 50 concurrent users. I disconnected and reconnected, even did a backup (to visit each record) and explicit sweep and made sure noone else was connected to the database late in the evening. No success. ... A couple of times I've seen problems vanish just by stopping/starting the Firebird service. Maybe just closing all connection or, at worst, restarting the service. Those problems occured after some metadata change (with connected users). The latest one was desctibed in a message to this list on January 14. (Subject: Firebird error: partner index description not found). Maybe you did some tinkering with the metadata? -- Aage J.
[firebird-support] Online DDL
Hello, I wonder if is it sure to perform changes to the database metadata while there are still users connected. Up to now, I allways shut the database down, perform DDL changes, and put it back on line. Is it actually necessary to do that ? Thanks for any help. Aldo Caruso
Re: [firebird-support] Online DDL
It depends on what kind of changes you plan to do. Some of them still needs exclusive access, otherwise you may end up with an object is in use error. Carlos Firebird Performance in Detail - http://videos.firebirddevelopersday.com www.firebirdnews.org - www.FireBase.com.br AC Hello, ACI wonder if is it sure to perform changes to the database metadata AC while there are still users connected. ACUp to now, I allways shut the database down, perform DDL changes, and AC put it back on line. ACIs it actually necessary to do that ? AC Thanks for any help. AC Aldo Caruso AC AC ++ AC Visit http://www.firebirdsql.org and click the Resources item AC on the main (top) menu. Try Knowledgebase and FAQ links ! AC Also search the knowledgebases at http://www.ibphoenix.com AC ++ AC Yahoo Groups Links
Re: [firebird-support] Online DDL
El 23/03/2014, a las 00:44, Carlos H. Cantu lis...@warmboot.com.br escribió: It depends on what kind of changes you plan to do. Some of them still needs exclusive access, otherwise you may end up with an object is in use error. I think Aldo asks If it is sure, because there are comments, some recent, that changing metadata while users connected can cause database corruption. Of course, If object in use raises, is not a problem, only if the database stay in the prior state after the error, but is a problem if trying to drop a table can cause database corruption. Jesus Garcia
Re: [firebird-support] Online DDL
Carlos, Frequently I modify stored procedures and triggers. If some user were connected before I started my transaction (the one which changes the stored procedure) he will still be using the unmodified version of the stored procedure. On the other hand, users who connects after I commit my transaction will be using the modified version. In that case is there a risk that two different versions of the same stored procedure coexist (in different transactions) or, as you say, the object is in use error prevents this conflicts and only allows me to alter the stored procedure when no user is excecuting it ? Thanks, Aldo El 22/03/14 20:44, Carlos H. Cantu escribió: It depends on what kind of changes you plan to do. Some of them still needs exclusive access, otherwise you may end up with an object is in use error. Carlos Firebird Performance in Detail - http://videos.firebirddevelopersday.com www.firebirdnews.org - www.FireBase.com.br AC Hello, AC I wonder if is it sure to perform changes to the database metadata AC while there are still users connected. AC Up to now, I allways shut the database down, perform DDL changes, and AC put it back on line. AC Is it actually necessary to do that ? AC Thanks for any help. AC Aldo Caruso AC AC ++ AC Visit http://www.firebirdsql.org and click the Resources item AC on the main (top) menu. Try Knowledgebase and FAQ links ! AC Also search the knowledgebases at http://www.ibphoenix.com AC ++ AC Yahoo Groups Links
[firebird-support] Re: Online DDL
23.03.2014 04:17, Aldo Caruso wrote: Frequently I modify stored procedures and triggers. If some user were connected before I started my transaction (the one which changes the stored procedure) he will still be using the unmodified version of the stored procedure. On the other hand, users who connects after I commit my transaction will be using the modified version. True. In that case is there a risk that two different versions of the same stored procedure coexist (in different transactions) Surely this may be undesired, but this risk is a documented behavior, AFAIK. Dmitry
Re: [firebird-support] Online DDL
My concern was about logical or business rules issues, not about database corruption, which I didn't know could happen. Why does corruption happen mixing DDL and DML in the same transaction ? Aldo El 22/03/14 20:55, Carlos H. Cantu escribió: No, corruption can happen if you mix DDL and DML in the same transaction. If you commit between them, you are safe. Carlos Firebird Performance in Detail - http://videos.firebirddevelopersday.com www.firebirdnews.org http://www.firebirdnews.org- www.FireBase.com.br http://www.FireBase.com.br El 23/03/2014, a las 00:44, Carlos H. Cantu lis...@warmboot.com.br mailto:lis...@warmboot.com.br escribió: It depends on what kind of changes you plan to do. Some of them still needs exclusive access, otherwise you may end up with an object is in use error. I think Aldo asks If it is sure, because there are comments, some recent, that changing metadata while users connected can cause database corruption. Of course, If object in use raises, is not a problem, only if the database stay in the prior state after the error, but is a problem if trying to drop a table can cause database corruption. Jesus Garcia
Re: [firebird-support] Re: Online DDL
Does this risk implies a database corruption or the risk only implies the undesired behaviour, from the logical point of view, of having two versions of the same stored procedure in two different transactions ( situation that ends when the older transaction commits or rolls back ) ? Aldo Caruso El 22/03/14 22:18, Dmitry Yemanov escribió: 23.03.2014 04:17, Aldo Caruso wrote: Frequently I modify stored procedures and triggers. If some user were connected before I started my transaction (the one which changes the stored procedure) he will still be using the unmodified version of the stored procedure. On the other hand, users who connects after I commit my transaction will be using the modified version. True. In that case is there a risk that two different versions of the same stored procedure coexist (in different transactions) Surely this may be undesired, but this risk is a documented behavior, AFAIK. Dmitry
