Changeset: b7df339ad803 for MonetDB
URL: http://dev.monetdb.org/hg/MonetDB?cmd=changeset;node=b7df339ad803
Modified Files:
sql/server/rel_select.c
Branch: stratified_sampling
Log Message:
Perform sampling before projection/group by rather than as an output modifier.
diffs (90 lines):
diff --git a/sql/server/rel_select.c b/sql/server/rel_select.c
--- a/sql/server/rel_select.c
+++ b/sql/server/rel_select.c
@@ -4701,7 +4701,35 @@ rel_select_exp(mvc *sql, sql_rel *rel, S
}
rel = r;
}
-
+ if (sn->sample) {
+ list *exps = new_exp_list(sql->sa);
+ if (sn->sample->token == SQL_WEIGHTED_SAMPLE) {
+ // weighted sampling
+ // parse the sample size and weight vector and pass it
on to rel_sample
+ dlist *l = sn->sample->data.lval;
+
+ lng sample_size = l->h->data.l_val;
+ sql_exp* sample_size_exp = exp_atom_lng(sql->sa,
sample_size);
+
+ exp_kind iek = {type_value, card_column, FALSE};
+ symbol* weights = l->h->next->data.sym;
+ sql_exp* weights_exp = rel_value_exp(sql, &rel,
weights, 0, iek);
+ if (!sample_size_exp || !weights_exp)
+ return NULL;
+ append(exps, sample_size_exp);
+ append(exps, weights_exp);
+
+ weighted_sample = 1;
+ } else {
+ // uniform sampling
+ // parse the sample size and pass it on to rel_sample
+ sql_exp *o = rel_value_exp( sql, &rel, sn->sample, 0,
ek);
+ if (!o)
+ return NULL;
+ append(exps, o);
+ }
+ rel = rel_sample(sql->sa, rel, exps);
+ }
if (rel) {
if (rel && sn->groupby) {
list *gbe = rel_group_by(sql, &rel, sn->groupby,
sn->selection, sql_sel );
@@ -4714,14 +4742,12 @@ rel_select_exp(mvc *sql, sql_rel *rel, S
if (!sn->having)
set_processed(rel);
}
-
if (sn->having) {
/* having implies group by, ie if not supplied do a group by */
if (rel->op != op_groupby)
rel = rel_groupby(sql, rel, NULL);
aggr = 1;
}
-
n = sn->selection->h;
rel = rel_project(sql->sa, rel, new_exp_list(sql->sa));
inner = rel;
@@ -4853,34 +4879,6 @@ rel_select_exp(mvc *sql, sql_rel *rel, S
rel = rel_topn(sql->sa, rel, exps);
}
- if (sn->sample) {
- list *exps = new_exp_list(sql->sa);
- if (sn->sample->token == SQL_WEIGHTED_SAMPLE) {
- // weighted sampling
- // parse the sample size and weight vector and pass it
on to rel_sample
- dlist *l = sn->sample->data.lval;
-
- lng sample_size = l->h->data.l_val;
- sql_exp* sample_size_exp = exp_atom_lng(sql->sa,
sample_size);
-
- symbol* weights = l->h->next->data.sym;
- sql_exp* weights_exp = rel_value_exp(sql, &rel,
weights, 0, ek);
-
- if (!sample_size_exp || !weights_exp)
- return NULL;
- append(exps, sample_size_exp);
- append(exps, weights_exp);
- } else {
- // uniform sampling
- // parse the sample size and pass it on to rel_sample
- sql_exp *o = rel_value_exp( sql, &rel, sn->sample, 0,
ek);
- if (!o)
- return NULL;
- append(exps, o);
- }
- rel = rel_sample(sql->sa, rel, exps);
- }
-
return rel;
}
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