This version of Rel includes bug fixes and enhancements, primarily
focusing on the Rel DBMS.
The following bugs have been fixed in Rel:
1. Assigning a relvar to itself (e.g., myrelvar := myrelvar) could
result in the Rel session becoming non-responsive. This has been
corrected.
2. Under certain conditions, updating a key attribute in a relvar
could result in the Rel session becoming non-responsive. This has
been corrected.
3. Under certain conditions, inserting tuples into a relvar from the
result of an expression that references the same relvar could
result in the Rel session becoming non-responsive. This has been
corrected.
4. Using INIT in a REAL relvar definition would correctly define the
relvar's attributes, but would not assign any tuples. This has
been corrected.
Some enhancements have been made:
1. Relation JOIN performance has been significantly improved. JOINs
on relational expressions of relatively large cardinality
demonstrate acceptable performance.
2. CPU consumption has been reduced during compilation of Java-based
TYPEs and OPERATORs.
3. Relvar update notices (e.g., "NOTICE: Updated 10000 tuples.",
"Notice: Delete 500 tuples." etc.) are now consolidated and only
appear at the end of a given execution. This prevents scripts that
perform a number of separate updates from producing a meaningless
proliferation of notices.
Also, a bug has been fixed in DBrowser:
1. A thread race condition that caused un-enhanced display to
sometimes duplicate or drop text has been corrected.
For more information, or to download Rel, see
http://dbappbuilder.sourceforge.net/Rel.html