X-Git-Url: https://git.rrq.au/?a=blobdiff_plain;f=vector%2Frelation.h;h=af0756cd09265c2e67196d7feff625bc38cf9c75;hb=813b52397a92922f2540a41c9076a77ca93e1a48;hp=b0996c16b34510649b6235e836a73b496fc80c2d;hpb=c08a0975036f23f972a16a07efb0c07113c96d2e;p=rrq%2Frrqmisc.git

diff --git a/vector/relation.h b/vector/relation.h
index b0996c1..af0756c 100644
--- a/vector/relation.h
+++ b/vector/relation.h
@@ -5,24 +5,33 @@
 #include <tupleitem.h>
 
 /**
- * A relation is an implementation of a tuple set with a primary key
- * through a hashvector whose "type" defines the key. Additional
- * hashvectors may be added to impose additional key restrictions and
- * the final relation is the intersection of them all.
- *
- * The relation record itself holds the column schema whereas the
- * indexes hold key schemas that in practice are copies of the column
- * schema with some columns blanked out.
+ * A relation is an implementation of a tuple set with (optional) key
+ * constraints. The store is a hashvector whose "type" is a
+ * tupleschema that defines the columns. The key constraints are
+ * represented as additional hashvectors whose tupleschemas are clones
+ * of the column schema with some columns excluded.
+ * \extends hashvector
  */
 typedef struct {
-    vector indexes; // one or more indexes over the tuple collection
-    tupleschema *columns;
+    /**
+     * This is the primary content store for the relation. Its type
+     * should be a tupleschema declaring the "item types" for the
+     * relation columns.
+     */
+    hashvector content;
+
+    /**
+     * This is a collection of relational constraints, if any, which
+     * are represented as hashvectors whose tupleschemas are clones of
+     * the content tupleschema with some columns excluded.
+     */
+    vector constraints;
 } relation;
 
 /**
- * Create a relation of the given arity and tupleschema.
+ * Create a relation for the given tupleschema.
  */
-extern relation *relation_create(int arity,tupleschema *schema);
+extern relation *relation_create(tupleschema *schema);
 
 /**
  * Add a a key index to the relation by identifying the value part for
@@ -32,9 +41,24 @@ extern int relation_addindex(relation *r,tupleschema *ts);
 
 
 /**
- * Add a tuple to a relation.
+ * \brief Add a tuple to a relation.
+ * \param r is th relation concerned.
+ * \param t is the tuple to add.
+ *
  * \returns a vector of all knocked out tuples.
  */
 extern vector *relation_add(relation *r,tuple *t);
 
+/**
+ * \brief Delete all tuples matching to the query.
+ * \returns all deleted tuples.
+ */
+extern vector *relation_delete(relation *r,tuple *query);
+
+/**
+ * \brief Return next tuple matching the query at or after the index.
+ * \returns any such matching tuple and updates *index to its index.
+ */
+extern void *relation_next(relation *r,vector_index *index,tuple *query);
+
 #endif