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+++ b/persistentstorage/dbms/group/TODO.TXT Fri Jan 22 11:06:30 2010 +0200
@@ -0,0 +1,27 @@
+Things that could be done to DBMS -- 12 October 1998
+
+Query optimizer:
+
+ Optimize for clustering indexes (use S/T and G/H plans)
+ e.g. assume Auto-increment column => clustering
+ or measure the clustering in the stats
+
+ Optimize for multi-column lookup
+ e.g. For "a=v1 and b=v2" with index on (a,b)
+
+ Optimize for like-predicates
+ e.g. "x LIKE 'abc*'" => "x>='abc' AND x<'abd'" etc.
+
+ Query complexity-reduction by removing redundant predicates, e.g.
+ "x>4 AND x>3" => "x>4"
+ "x>4 OR x>3" => "x>3"
+ "x>-1" for unsigned x => trivially true
+
+ Better statistical data dn guesswork
+
+SQL/access plans:
+
+ Support "DISTINCT" in the projection stage via a Hash-system or sorting
+
+
+