Hi All, While using my own implemented file system, the db file size will only expand and not prune even remove record from the db. Could anyone advise me that what I am missing in order to pruning the db size when removing a number of records? Jacky
On Wed, Aug 9, 2017 at 11:02 AM, Simon Slavin <slav...@bigfraud.org> wrote: > > > On 9 Aug 2017, at 3:31am, Jacky Lam <jacky...@gmail.com> wrote: > > > 1. Can I call sqlite3_open more than one times before calling > sqlite3_close > > and sqlite3_free? > > Call sqlite3_open() for each database you want to open. You can have any > number of databases open at the same time. Call sqlite3_close() for each > database you have open when you no longer need it. After closing the last > connection call sqlite3_shutdown() as described in > > <https://sqlite.org/c3ref/initialize.html> > > (The above ignores use of SQL's ATTACH command.) > > You are not expected to ever call sqlite3_free() unless you are using > SQLite to do other memory-handing tasks for you. Most people who use > SQLite never call sqlite3_free(). > > > 2. If the above mentioned devices change to mutli-thread setting but no > > thread safe functions such as mutex, is this setting still fine? > > You have explicitly declared SQLITE_THREADSAFE=0 . That means you will > arrange that only one thread will be doing SQLite calls at once. As long > as you can ensure this, SQLite will function correctly. > > > If not, how can I make it thread safe with lack of mutex support in > > the system? > > Do any of the following: > > A) Implement your own mutex system. > > B) Use SQLite’s mutex system ( <https://sqlite.org/c3ref/mutex_alloc.html> > ) > > C) Supply the value SQLITE_OPEN_FULLMUTEX when you open connections using > sqlite3_open_v2(), as described in <https://sqlite.org/c3ref/open.html> . > > Please note that the above is a top-of-the-head answer and I have not > personally tries each of the options to make sure it works. > > Simon. > _______________________________________________ > sqlite-users mailing list > sqlite-users@mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
