Developer Discussions

[mheras]

Hi Lukask.

We need to merge multiple gpkg files in one.

For that exist the function "attack database" but have the limitation of 10 files and we need to attack more.

Example:

sqlite3 icgc17.gpkg

attach database 'icgc1.gpkg' as 'icgc1';

...

In sqllite3 exist the constant SQLITE_LIMIT_ATTACHED and aparently is possible to overwrite.

We tried  change unsuccessfully

sqlite3_limit(db,SQLITE_LIMIT_ATTACHED,20);

Any idea?

Can you help us?

Best Regards,

Marti.

[lukasz.baraniak · Accepted solution]

The SQLITE_LIMIT_ATTACHED is a runtime configurable limit which by default is set to 10. The sqlite3_limit(db,SQLITE_LIMIT_ATTACHED,20); is a function invocation you'd need to place in your code linking against the SQLite lib. To change the limit in the sqlite3 shell, you would use:

.limit attached 20

BUT! The SQLITE_LIMIT_ATTACHED has a hard limit that is a compiled constant in the binaries and it's set to 10 as well, so unless you recompile your SQLite binaries with a change SQLITE_MAX_ATTACHED, there is no way to overcome the limit of 10 attached databases.