* Now we take into account the call hierarchy when use SQL SECURITY
option.
Added new context variable in SYSTEM namespace - EFFICIENT_USER which is
returns user name in which context a code works.
We change efficient user before call procedure and function, fetch a
record from selective procedure and before execute a trigger.
* Renamed new context variable to EFFECTIVE_USER. Fixed nested calls.
* Improved error messages to print effective user when there is no permission.
* Added description of new context variable EFFECTIVE_USER. Improved description of SQL SECURITY clause.
With this feature it's possible to create parallel (via different attachments) processes reading consistent data from a database.
For example, a backup process may create multiple threads paralleling read data from the database.
Also a web service may dispatch distributed sub services paralleling doing some processing.
That is accomplished creating a transaction with SET TRANSACTION SNAPSHOT [ AT NUMBER <snapshot number> ] or isc_tpb_at_snapshot_number.
The <snapshot number> from the first transaction may be obtained with RDB$GET_CONTEXT('SYSTEM', 'SNAPSHOT_NUMBER') or transaction info call with fb_info_tra_snapshot_number.
Also added CORE-6017 - Add transaction info fb_info_tra_snapshot_number.
* Initial implementation of replication
* Postfixes for configuration and Windows builds
* Misc Windows adjustments
* Forgotten changes from prior commits
* Last round (fingers crossed) of fixing the Windows build
* Improve self-documentation
* Misc improvements
* Updates the docs
* More configuration
* Frontported some remaining pieces
* Installation post-fixes
* Special permission for replication
* Fixed issue: Database is corrupted when conflicting "starting at page" values is specified for secondary files
* Raise error when conflicting "starting at page" values is specified for secondary database files
- ignore prepared 2PC transactions when check if session reset is allowed
- if there is current active user transaction - rollback it before session reset and start new transaction with same properties after reset
- add warning if current transaction changes any table before reset
I didn't verified why the error messages are being truncated. It seems idiotic if
the engine, library or ISQL does not accept these not-so-detailed messages.
