Changeset: 6a6069579c30 for MonetDB
URL: http://dev.monetdb.org/hg/MonetDB?cmd=changeset;node=6a6069579c30
Modified Files:
sql/server/rel_graph.c
sql/server/rel_optimizer.c
sql/server/rel_rel.c
sql/server/rel_rel.h
Branch: graph0
Log Message:
QRW: transform graph_select(A x B) into graph_join(A, B)
diffs (truncated from 403 to 300 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
@@ -91,21 +91,14 @@ sql_rel* rel_graph_reaches(mvc *sql, sql
if(!qto) return NULL; // cannot convert qto into the same type of eto
// build the new operator graph join operator
- graph_ptr = (sql_graph*) sa_alloc(sql->sa, sizeof(sql_graph));
+ graph_ptr = rel_graph_create(sql->sa);
if(!graph_ptr) { return sql_error(sql, 03, "Cannot allocate rel_graph"); }
- memset(graph_ptr, 0, sizeof(sql_graph));
result = (sql_rel*) graph_ptr;
- sql_ref_init(&result->ref);
result->op = op_graph_select;
result->l = rel;
- exp_ptr = (sql_exp*) sa_alloc(sql->sa, sizeof(sql_exp));
+ exp_ptr = exp_graph(sql, sa_list(sql->sa), sa_list(sql->sa));
if(!exp_ptr) { return sql_error(sql, 03, "Cannot allocate sql_exp
[e_graph] "); }
- memset(exp_ptr, 0, sizeof(sql_exp));
- exp_ptr->type = e_graph;
- exp_ptr->card = CARD_MULTI;
- exp_ptr->l = sa_list(sql->sa);
list_append(exp_ptr->l, qfrom);
- exp_ptr->r = sa_list(sql->sa);
list_append(exp_ptr->r, qto);
result->exps = sa_list(sql->sa); // by convention exps has to be a list,
even it contains only one item
list_append(result->exps, exp_ptr);
diff --git a/sql/server/rel_optimizer.c b/sql/server/rel_optimizer.c
--- a/sql/server/rel_optimizer.c
+++ b/sql/server/rel_optimizer.c
@@ -1364,8 +1364,14 @@ static sql_exp *
case e_atom:
case e_psm:
return e;
- case e_graph:
- assert(0 && "Not implemented yet");
+ case e_graph: {
+ list *lst1 = NULL, *lst2 = NULL;
+ lst1 = exps_push_down(sql, e->l, f, t);
+ if(list_empty(lst1)) return NULL;
+ lst2 = exps_push_down(sql, e->r, f, t);
+ if(list_empty(lst2)) return NULL;
+ return exp_graph(sql, lst1, lst2);
+ } break;
}
return NULL;
}
@@ -8435,7 +8441,6 @@ rel_apply_rewrite(int *changes, mvc *sql
}
if (rel->flag == APPLY_LOJ && r->op == op_select) {
sql_rel *nr, *ns;
-
nr = rel_project(sql->sa, rel_dup(r),
rel_projections(sql, r, NULL, 1, 1));
ns = rel_apply(sql, rel_dup(rel->l), nr, rel->exps, rel->flag);
@@ -8629,6 +8634,168 @@ rel_apply_rewrite(int *changes, mvc *sql
}
static sql_rel *
+rel_graph_pda(int *changes, mvc *sql, sql_rel *rel)
+{
+ sql_rel* graph_rel = rel;
+ sql_rel* parent = NULL;
+ sql_rel* target = NULL;
+ sql_exp* graph_pda = NULL;
+
+ // only applies to op_graph_select
+ if(graph_rel->op != op_graph_select) {
+ return rel;
+ }
+ graph_pda = graph_rel->exps->h->data;
+ assert(graph_pda != NULL && "Interesting, here we have a graph select
without a predicate...");
+ assert(graph_pda->type == e_graph);
+
+ target = parent = rel->l;
+
+ // pass through selects
+ if(target->op == op_select){
+ target = target->l;
+ }
+
+ // do not cross references
+ if(rel_is_ref(target) || rel_is_ref(parent))
+ return rel;
+
+ // ref cnt
+ printf("[rel_graph_pda] cnt: %d\n", graph_rel->ref.refcnt);
+
+ // case 1 - try to push down through a join or another graph operator
+ if(is_join(target->op) || is_graph(target->op)){
+ sql_rel* l = target->l;
+ sql_rel* r = target->r;
+ sql_exp* ne = NULL;
+ bool pda_lhs = true; // otherwise go to the right
+
+ // can we push down to the lhs or rhs of the join?
+ bool left = r->op == op_join || r->op == op_left || r->op ==
op_graph_join || r->op == op_graph_select;
+ bool right = r->op == op_join || r->op == op_right || r->op ==
op_graph_join;
+
+ // push down to the lhs
+ if (left){
+ ne = exp_push_down(sql, graph_pda, l, l);
+ }
+ // try to push to the rhs
+ if (!ne && right) {
+ pda_lhs = false;
+ ne = exp_push_down(sql, graph_pda, r, r);
+ }
+
+ // success?
+ if (ne) {
+ list_remove_node(graph_rel->exps, graph_rel->exps->h);
+ assert(list_empty(graph_rel->exps));
+ list_append(graph_rel->exps, ne);
+
+ // reshape the tree
+ if (pda_lhs){
+ graph_rel->l = target->l;
+ target->l = graph_rel;
+ } else {
+ graph_rel->l = target->r;
+ target->r = graph_rel;
+ }
+
+ (*changes)++;
+ return parent;
+ }
+ }
+
+ return rel;
+}
+
+static sql_rel *
+rel_graph_create_join(int *changes, mvc *sql, sql_rel *rel)
+{
+ sql_rel* graph_rel = rel;
+ sql_rel* parent = NULL;
+ sql_rel* target = NULL;
+ sql_exp* graph_pda = NULL;
+
+ // only applies to op_graph_select
+ if(graph_rel->op != op_graph_select || rel_is_ref(rel)) {
+ return rel;
+ }
+ graph_pda = graph_rel->exps->h->data;
+ assert(graph_pda != NULL && "Interesting, here we have a graph select
without a predicate...");
+ assert(graph_pda->type == e_graph);
+
+ target = rel->l;
+
+ // pass through selects
+ if(target->op == op_select){
+ parent = target;
+ target = target->l;
+ }
+
+ // do not cross references
+ if(rel_is_ref(target) || (parent && rel_is_ref(parent)))
+ return rel;
+
+ // check the parent is a cross product
+ if(target->op == op_join && list_empty(target->exps)){
+ sql_rel *l = target->l;
+ sql_rel *r = target->r;
+ bool order_lhs = true; // otherwise go the left hand side
+ list *el = NULL;
+ list *er = NULL;
+
+ // bind to the lhs
+ el = exps_push_down(sql, graph_pda->l, l, l);
+ if(!el){ // ok that didn't work out, try with the rhs
+ order_lhs = false;
+ el = exps_push_down(sql, graph_pda->l, r, r);
+ }
+
+ // if we did bind the lhs above, then we are guaranteed that the
+ // rhs will bind as well. Otherwise we are in the case where
+ // the rule `rel_graph_pda' would have move this operator above
+ // this cross product.
+ if(el){
+ sql_exp* ne = NULL; // construct the new e_graph
expression (jic)
+
+ if(order_lhs){
+ er = exps_push_down(sql, graph_pda->r, r, r);
+ } else {
+ er = exps_push_down(sql, graph_pda->r, l, l);
+ }
+ assert(er != NULL && "See comment in the code above");
+ ne = exp_graph(sql, el, er);
+
+ // replace the cross product with a graph_join
+ rel_destroy(target);
+ target = (sql_rel*) rel_graph_create(sql->sa);
+ memcpy(target, graph_rel, sizeof(sql_graph));
+ target->op = op_graph_join;
+ target->exps = new_exp_list(sql->sa);
+ list_append(target->exps, ne);
+ target->l = l;
+ target->r = r;
+
+ // replace the graph_select with a dummy operator
+ graph_rel->op = op_select;
+ graph_rel->exps = new_exp_list(sql->sa);
+ graph_rel->p = NULL;
+
+ // update the parent
+ if(parent){
+ parent->l = target;
+ parent->nrcols = target->nrcols;
+ } else {
+ graph_rel->l = target;
+ }
+
+ (*changes)++;
+ }
+ }
+
+ return rel;
+}
+
+static sql_rel *
rewrite(mvc *sql, sql_rel *rel, rewrite_fptr rewriter, int *has_changes)
{
int changes = 0;
@@ -8753,6 +8920,7 @@ static sql_rel *
_rel_optimizer(mvc *sql, sql_rel *rel, int level)
{
int changes = 0, e_changes = 0;
+ bool graph_operators = false;
global_props gp;
memset(&gp, 0, sizeof(global_props));
@@ -8768,6 +8936,9 @@ static sql_rel *
}
#endif
+ // do we have any graph operators around?
+ graph_operators = gp.cnt[op_graph_select] || gp.cnt[op_graph_join];
+
/* simple merging of projects */
if (gp.cnt[op_project] || gp.cnt[op_ddl]) {
rel = rewrite(sql, rel, &rel_merge_projects, &changes);
@@ -8839,6 +9010,16 @@ static sql_rel *
rel = rewrite(sql, rel, &rel_remove_empty_select, &e_changes);
}
+ if (graph_operators){
+ rel = rewrite_topdown(sql, rel, rel_graph_pda, &changes);
+ printf("[Optimizer] rel_graph_pda: %s\n", dump_rel(sql, rel));
+ rel = rewrite_topdown(sql, rel, rel_graph_create_join,
&changes);
+ printf("[Optimizer] rel_graph_create_join: %s\n", dump_rel(sql,
rel));
+ // rel_graph_create_join creates empty (dummy) selects
+ rel = rewrite(sql, rel, &rel_remove_empty_select, &e_changes);
+ printf("[Optimizer] rel_remove_empty_select: %s\n",
dump_rel(sql, rel));
+ }
+
if (gp.cnt[op_select] && gp.cnt[op_join]) {
rel = rewrite_topdown(sql, rel, &rel_push_select_down_join,
&changes);
rel = rewrite(sql, rel, &rel_remove_empty_select, &e_changes);
@@ -8871,6 +9052,8 @@ static sql_rel *
rel = rewrite(sql, rel, &rel_groupby_distinct, &changes);
}
+
+ printf("[Optimizer] rel_join_order before: %s\n", dump_rel(sql, rel));
if (gp.cnt[op_join] || gp.cnt[op_left] || gp.cnt[op_semi] ||
gp.cnt[op_anti]) {
rel = rel_remove_empty_join(sql, rel, &changes);
if (!gp.cnt[op_update])
@@ -8879,6 +9062,7 @@ static sql_rel *
/* rel_join_order may introduce empty selects */
rel = rewrite(sql, rel, &rel_remove_empty_select, &e_changes);
}
+ printf("[Optimizer] rel_join_order after: %s\n", dump_rel(sql, rel));
if (gp.cnt[op_select] && sql->emode != m_prepare)
rel = rewrite(sql, rel, &rel_simplify_like_select, &changes);
diff --git a/sql/server/rel_rel.c b/sql/server/rel_rel.c
--- a/sql/server/rel_rel.c
+++ b/sql/server/rel_rel.c
@@ -100,6 +100,16 @@ rel_create( sql_allocator *sa )
return r;
}
+sql_graph*
+rel_graph_create( sql_allocator *sa )
+{
+ sql_graph *r = SA_NEW(sa, sql_graph);
+ if(!r) return NULL;
+ memset(r, 0, sizeof(sql_graph));
+ sql_ref_init(&(r->relation.ref));
+ return r;
+}
+
sql_rel *
rel_copy( sql_allocator *sa, sql_rel *i )
{
@@ -178,12 +188,15 @@ rel_bind_column_(mvc *sql, sql_rel **p,
{
int ambiguous = 0;
sql_rel *l = NULL, *r = NULL;
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