Thank you very much Fabiano, that's a very good idea. Greetings.
Walter. On Fri, May 3, 2013 at 1:52 PM, Fabiano Kureck <fabianoas...@gmail.com>wrote: > ** > > > You can take a look in the Firebird-Internals.pdf file. It can be found in > Firebird site. > It is very interesting! Read, create a demo database and use a hexadecimal > editor ;) > > > -----Mensagem original----- > De: firebird-support@yahoogroups.com > [mailto:firebird-support@yahoogroups.com] Em nome de W O > Enviada em: sexta-feira, 3 de maio de 2013 14:20 > > Para: firebird-support@yahoogroups.com > Assunto: Re: [firebird-support] Re: use of -USE_ALL_SPACE > > That's very interesting Fabiano, thank you very much for your answer. > > Greetings. > > Walter. > > On Fri, May 3, 2013 at 1:12 PM, Fabiano Kureck > <fabianoas...@gmail.com>wrote: > > > ** > > > > > > > Yes, you are wright. > > And in a particular Page it is only allowed a single type of: > > Table Data or index or generator and so on > > > > -----Mensagem original----- > > De: firebird-support@yahoogroups.com > > [mailto:firebird-support@yahoogroups.com] Em nome de W O > > Enviada em: sexta-feira, 3 de maio de 2013 12:42 > > Para: firebird-support@yahoogroups.com > > Assunto: Re: [firebird-support] Re: use of -USE_ALL_SPACE > > > > > > Thank you very much Ann, your explanation was (as usual) very good. > > > > Just one more question: > > > > As I understand it, in a page just can be the rows (records) of a single > > table. No two or more tables can share a page. > > > > Am I right? > > > > Greetings. > > > > Walter. > > > > On Fri, May 3, 2013 at 10:59 AM, Ann Harrison > > <aharri...@ibphoenix.com>wrote: > > > > > ** > > > > > > > > > > > Walter, > > > > > > > > > > As I understand it when a record is deleted a new primary version > with > > a > > > > mark (a flag) is put on it indicating that fact and the previous > > version > > > of > > > > the record is copied on another location (same page if there is room > or > > > > another page if there is not) > > > > > > > > Is that true? > > > > > > > > > > More or less. A new "deleted stub" record - a header with no data - is > > > created and stored on the record's home page. If there's not room on > > > the home page for the deleted stub, then the oldest version of the > record > > > on the page will be moved elsewhere. > > > > > > It's probably worth noting, for those who are thinking about > implementing > > > relational database managers, that records can be relocated on page > > > freely. > > > > > > The record number (RDB$DB_KEY and all its aliases) is the value > > > used in indexes to identify a specific record. That number consists of > > > a pointer page identifier - the ordinal number of a row in RDB$PAGES > for > > > pointer pages for that table - plus the offset on the pointer page that > > > contains the page number of the record's home page, plus the offset > > > of an index on that page that contains the offset and length of the > data > > > on page. So... > > > > > > 1) Reorganizing data on a page just requires swapping values in the > index > > > for that page to maintain stable record numbers. > > > > > > 2) All versions of a record use the same record number. > > > > > > 3) Updating a record does not require changing all the indexes on the > > > table. If the key doesn't change, neither does the index. > > > > > > However, once a record has been deleted and garbage collected, its > > > record number is released and will be reused, so record numbers are > > > not stable outside of a single transaction - unless you use a switch > > > to make record numbers stable for your connection. Record numbers > > > will change after a gbak restore. > > > > > > > > > Good luck, > > > > > > Ann > > > > > > [Non-text portions of this message have been removed] > > > > > > > > > > > > > [Non-text portions of this message have been removed] > > > > ------------------------------------ > > > > > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > > > Visit http://www.firebirdsql.org and click the Resources item > > on the main (top) menu. Try Knowledgebase and FAQ links ! > > > > Also search the knowledgebases at http://www.ibphoenix.com > > > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > Yahoo! Groups Links > > > > > > > > [Non-text portions of this message have been removed] > > ------------------------------------ > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > Visit http://www.firebirdsql.org and click the Resources item > on the main (top) menu. Try Knowledgebase and FAQ links ! > > Also search the knowledgebases at http://www.ibphoenix.com > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > Yahoo! Groups Links > > > [Non-text portions of this message have been removed] ------------------------------------ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Visit http://www.firebirdsql.org and click the Resources item on the main (top) menu. Try Knowledgebase and FAQ links ! Also search the knowledgebases at http://www.ibphoenix.com ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/firebird-support/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/firebird-support/join (Yahoo! ID required) <*> To change settings via email: firebird-support-dig...@yahoogroups.com firebird-support-fullfeatu...@yahoogroups.com <*> To unsubscribe from this group, send an email to: firebird-support-unsubscr...@yahoogroups.com <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/