Changeset: e03fa66a96b5 for MonetDB
URL: http://dev.monetdb.org/hg/MonetDB?cmd=changeset;node=e03fa66a96b5
Modified Files:
sql/server/rel_graph.c
sql/server/sql_scan.c
Branch: graph1
Log Message:
Semantic: support for CHEAPEST SUM(e: expr)
Explicitly bind the edge table from the argument of CHEAPEST SUM,
identified by the string preceding the colon (:).
diffs (192 lines):
diff --git a/sql/server/rel_graph.c b/sql/server/rel_graph.c
--- a/sql/server/rel_graph.c
+++ b/sql/server/rel_graph.c
@@ -109,7 +109,6 @@ sql_rel* rel_graph_reaches(mvc *sql, sql
static bool error_reported(mvc* sql){ return (sql->session->status < 0); }
-
static sql_exp* bindg_ret(mvc *sql, sql_exp* bind1, sql_exp* bind2){
if (error_reported(sql)){ // an error already occurred
return NULL;
@@ -122,60 +121,71 @@ static sql_exp* bindg_ret(mvc *sql, sql_
}
}
-static sql_exp* bindg_exp(mvc *sql, sql_exp *exp, dlist *parse_tree){
- graph_join *g =NULL;
- sql_exp* e =NULL;
- exp_kind exp_kind_value = {type_value, card_column, TRUE};
+static sql_exp* bindg_filter_graph(mvc *sql, sql_exp *exp, dlist *parse_tree){
const char* table_ref = NULL; // the table referred (optional)
symbol* expr_weight = NULL; // the expression inside CHEAPEST SUM ( ...
);
+ graph_join* g = NULL;
+ sql_exp* e = NULL;
+ exp_kind exp_kind_value = {type_value, card_column, TRUE};
assert(exp && "Expected an expression");
+ assert(exp->type == e_cmp && get_cmp(exp) == cmp_filter_graph &&
"Expected a graph filter exp~");
assert(parse_tree && "The input argument parse_tree is NULL");
assert(parse_tree->cnt == 2 && "Expected two nodes in the root of the
parse tree");
- if(exp->type != e_cmp || get_cmp(exp) != cmp_filter_graph){
- // this is not a graph join, move along
- return NULL;
- }
-
- (void) sql;
- (void) g;
- (void) e;
- (void) exp_kind_value;
- (void) table_ref;
- (void) expr_weight;
+ g = exp->f;
table_ref = parse_tree->h->data.sval;
expr_weight = parse_tree->h->next->data.sym;
+ if (table_ref){ // use the table name to refer to the edge table
+ const char* tname = rel_name(g->edges);
- return NULL;
+ // TODO shall we consider the schema as well?
+ assert(tname != NULL);
+ if(strcmp(tname, table_ref) == 0){
+ // force the binding against this relation
+ e = rel_value_exp(sql, &(g->edges), expr_weight,
sql_sel, exp_kind_value);
+ if(!e){ return sql_error(sql, 02, "Cannot bind the
cheapest sum expression in the subquery `%s'", tname); }
+ }
+ } else { // table name not given
+ // try to bind the expression a la `best effort'
+ e = rel_value_exp(sql, &(g->edges), expr_weight, sql_sel,
exp_kind_value);
+ }
-// g = exp->f;
-//
-// // try to bind the expression
-// e = rel_value_exp(sql, &(g->edges), sym, sql_sel, exp_kind_value);
-// if(!e){ return NULL; }
-//
-// // an expression has already been bound
-// if(g->cost){
-// return sql_error(sql, 02, "TODO: At the moment you cannot bind
multiple CHEAPEST SUM expression against the same join");
-// }
-//
-// // found it!
-// g->cost = exp_label(sql->sa, e, ++sql->label);
-// return g->cost;
+ // did we bind our parse tree?
+ if(e){
+ if(g->cost){ // existing limitation, an expression has already
been bound
+ return sql_error(sql, 02, "TODO: At the moment you
cannot bind multiple CHEAPEST SUM expression against the same join");
+ }
+
+ // found it!
+ g->cost = exp_label(sql->sa, e, ++sql->label);
+ return g->cost;
+
+ } else { // no, we didn't bind it
+ return NULL;
+ }
}
+static sql_exp* bindg_exp(mvc *sql, sql_exp *exp, dlist *parse_tree){
+ if(exp->type == e_cmp && get_cmp(exp) == cmp_filter_graph){
+ // ok this is a graph join
+ return bindg_filter_graph(sql, exp, parse_tree);
+ } else {
+ // this is not a graph join, move along
+ return NULL;
+ }
+}
-static sql_exp* bindg_exps(mvc *sql, list *exps, dlist *sym){
+static sql_exp* bindg_exps(mvc *sql, list *exps, dlist *parse_tree){
sql_exp *result = NULL;
// edge case
if(!exps || error_reported(sql)) return NULL;
for(node* n = exps->h; n; n = n->next){
- sql_exp *bound = bindg_exp(sql, n->data, sym);
+ sql_exp *bound = bindg_exp(sql, n->data, parse_tree);
result = bindg_ret(sql, result, bound);
if(error_reported(sql)) return NULL; // ERROR! => stop
processing
}
@@ -183,7 +193,7 @@ static sql_exp* bindg_exps(mvc *sql, lis
return result;
}
-static sql_exp* bindg_rel(mvc *sql, sql_rel* relation, dlist *sym){
+static sql_exp* bindg_rel(mvc *sql, sql_rel* relation, dlist *parse_tree){
// edge case
if(!relation || error_reported(sql)) return NULL;
@@ -197,20 +207,20 @@ static sql_exp* bindg_rel(mvc *sql, sql_
case op_join: {
sql_exp *exp1 = NULL, *exp2 = NULL, *exp3 = NULL, *ret = NULL;
- exp1 = bindg_rel(sql, relation->l, sym);
- exp2 = bindg_rel(sql, relation->r, sym);
+ exp1 = bindg_rel(sql, relation->l, parse_tree);
+ exp2 = bindg_rel(sql, relation->r, parse_tree);
ret = bindg_ret(sql, exp1, exp2);
- exp3 = bindg_exps(sql, relation->exps, sym);
+ exp3 = bindg_exps(sql, relation->exps, parse_tree);
return bindg_ret(sql, ret, exp3);
} break;
case op_select: {
- sql_exp* exp1 = bindg_exps(sql, relation->exps, sym);
- sql_exp* exp2 = bindg_rel(sql, relation->l, sym);
+ sql_exp* exp1 = bindg_exps(sql, relation->exps, parse_tree);
+ sql_exp* exp2 = bindg_rel(sql, relation->l, parse_tree);
return bindg_ret(sql, exp1, exp2);
} break;
case op_groupby:
- // move up the tree
- return bindg_rel(sql, relation->l, sym);
+ // move up in the tree
+ return bindg_rel(sql, relation->l, parse_tree);
default:
return NULL;
}
@@ -218,23 +228,15 @@ static sql_exp* bindg_rel(mvc *sql, sql_
return NULL; // silent the warning
}
-
sql_exp* rel_graph_cheapest_sum(mvc *sql, sql_rel **rel, symbol *sym, int
context){
sql_exp* exp_bound = NULL;
sql_exp* result = NULL;
+ assert(sym->data.lval != NULL && "CHEAPEST SUM: empty parse tree");
+
// Check the context is the SELECT clause
if(context != sql_sel){
- sql_error(sql, 02, "CHEAPEST SUM is only allowed inside the
SELECT clause");
- return NULL;
- }
-
- // Check whether an argument has been specified
- if(!sym->data.lval){
- // TODO: actually this case is not part of the parser language,
i.e. it never occurs
- // perhaps it should be implicitly treated as CHEAPEST SUM (1) ?
- sql_error(sql, 02, "Empty argument for CHEAPEST SUM");
- return NULL;
+ return sql_error(sql, 02, "CHEAPEST SUM is only allowed inside
the SELECT clause");
}
// Find the relation where the sub the expression binds to
diff --git a/sql/server/sql_scan.c b/sql/server/sql_scan.c
--- a/sql/server/sql_scan.c
+++ b/sql/server/sql_scan.c
@@ -1097,6 +1097,9 @@ int scanner_symbol(mvc * c, int cur)
utf8_putchar(lc, cur);
return scanner_token(lc, '|');
}
+ case ':': /* CHEAPEST SUM (e: expr) */
+ lc->started = 1;
+ return scanner_token(lc, ':');
}
(void)sql_error( c, 3, "unexpected symbol (%lc)", (wint_t) cur);
return LEX_ERROR;
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