E-Maj - Release notes
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0.7.1
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Enhancements:
- add a emaj_snap_group function for test purpose that snaps all tables
and sequences of a group on individual files located into a given directory.
- add a warning at create_group time if tables have (non emaj) triggers.
- decrease the level of locks set at emaj_create_group or emaj_set_mark_group 
time from ACCESS EXCLUSIVE (the default lock mode) to EXCLUSIVE so that 
ACCESS SHARE locks generated by read accesses don't conflict with emaj 
activity.
- minor coding improvement.
- this version is also tested with postgresql 9.0 beta 2.

Bug fix:
- in log_only mode, solve the problem encountered when creating log for 
a table without primary key.
- fix the error occuring when a emaj_reset_group was not executed prior an 
emaj_drop_group. Take the opportunity to use cascading deletes provided by
foreign keys referencing emaj_group table.
- fix the emaj_create_group function to get correct numbers of tables and 
sequences in emaj_group table.
- fix rollback aborts on UPDATEs when several clients accessed the 
database in parallel resulting in both log rows for each UPDATE (one for 
old values and the other for new values) not strictly in sequence.
- when rollbacking a table, finaly also rollback the state of the sequence 
associated to the log id so that the statistics produced by the 
function emaj_rlbk_stat_group are correct after a rollback operation.
- fix error when rollbacking tables having foreign keys with case sensitive 
name.

0.7
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Enhancements:
- add a feature to perform parallel rollbacks, in order to speed up the 
rollback operations on multi-processor servers. A PHP command is created
for this purpose: emajParallelRollback.php.
- the emaj_reset_group function is not necessary anymore before starting 
a group ; the log purge is automaticaly done at emaj_start_group function ;
But the emaj_reset_function remains so user can purge log tables sooner.
- issue a warning at emaj_create_group, emaj_start_group and 
emaj_rollback_group if either a table of the group has a foreign key that
reference a table outside the group or a table of the group is referenced
by a table outside the group.
- before a rollback operation, drop the foreign keys belonging to or 
referencing any group's table and recreate them after
- add a serial id to the emaj_hist table to avoid potential duplicate key
conditions if 2 events happen in the same micro-second.
- the table previsously named emaj_group becomes emaj_group_def, column 
names being slightly changed. This impact ts E-maj usage.
- a new table emaj_relation, records working data about the relation 
belonging to all created groups. It provides a stability of the group 
composition during its entire life (between emaj_create_group and 
emaj_drop_group function calls).
- a new internal table emaj_group maintain the state of managed groups.
- a new table emaj_param stores E-maj parameters. A first emaj_version 
parameter records the current emaj version.
- the emaj_delete_group function has been renamed into emaj_drop_group.
This impacts E-maj usage.
- add a parameter named 'log_only' that allow to configure E-maj in a mode 
that disables rollback operations. This permits users to test E-maj logging 
with tables for which a primary key is not yet created.
- add an automatic deletion of oldest rows in the emaj_hist table. To achieve
this, a parameter, named 'history_retention' is created in the emaj_param 
table, with a default value of 1 month. This value can be changed by the 
user. This history purge is done at every emaj_start_group time.
- enhance the checks of emaj environment, by checking the internal 
consistency at group level.
- provide to users a function that checks that no residual functions or log 
tables remain in the emaj environment.
- in all rollback functions (in parallel or not) it is possible for user to 
use the keyword 'EMAJ_LAST_MARK' as mark name. This pseudo name is equivalent
to the last active mark that exists for the group. It can also be used in 
emaj_rlbk_stat_group function

Bug fixes:
- change emaj_delete_group, emaj_start_group and emaj_reset_group functions 
to add a check that the group to process is not in logging state

0.6
---
Enhancements:
- add an emaj_rollback_and_stop_group function to rollback a table_group and 
stop it at the same time. 
This allow to not delete the rollbacked rows from log tables and then speed
up the rollback function when there is no need to keep any previous mark 
active.
- when an emaj_stop_group function is performed, the marks in emaj.marks 
table are not physicaly deleted but their state just becomes "deleted". The 
associated data in emaj_sequence table (that record the serial value of each 
log table) are also not deleted. 
This allow to find marks timestamps if log tables are used for application 
debugging purpose.
The emaj_reset_group function physicaly deletes the marks for the group at 
the same time it truncates the related log tables.
Note that deleted marks can be referenced in emaj_log_stat_group function 
calls.
- change column names from emaj_hist table to get a better consistency 
between table name and columns name prefix

Bug fixes:
- in rollback operations, don't delete the mark used to rollback to, and its 
associated data for sequences, because it can be useful for a future use if 
the application continues after the rollback operation.

0.5.2
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Bug fixes:
- the UPDATE statements generated for the rollback functions did not handle 
properly the columns list of the SET clause.
- supply the right test-emaj.sql file !

0.5.1
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Bug fixes:
- when a table has several indexes, the UPDATE or DELETE statements generated 
by the emaj_rollback_group function was often erroneous.

Enhancements:
- replace the current_timestamp default value for emaj_changed column of log 
tables by clock_timestamp() so that every log row has its own creation 
timestamp.

0.5
---
First released version


