Examples with CachingRelMetadataProvider org.apache.calcite.rel.metadata.CachingRelMetadataProvider used on opensource projects

Example 6 with CachingRelMetadataProvider

use of org.apache.calcite.rel.metadata.CachingRelMetadataProvider in project calcite by apache.

the class RelMetadataTest method testCustomProvider.

@Test
public void testCustomProvider() {
    final List<String> buf = Lists.newArrayList();
    ColTypeImpl.THREAD_LIST.set(buf);
    final String sql = "select deptno, count(*) from emp where deptno > 10 " + "group by deptno having count(*) = 0";
    final RelRoot root = tester.withClusterFactory(new Function<RelOptCluster, RelOptCluster>() {

        public RelOptCluster apply(RelOptCluster cluster) {
            // Create a custom provider that includes ColType.
            // Include the same provider twice just to be devious.
            final ImmutableList<RelMetadataProvider> list = ImmutableList.of(ColTypeImpl.SOURCE, ColTypeImpl.SOURCE, cluster.getMetadataProvider());
            cluster.setMetadataProvider(ChainedRelMetadataProvider.of(list));
            return cluster;
        }
    }).convertSqlToRel(sql);
    final RelNode rel = root.rel;
    // Top node is a filter. Its metadata uses getColType(RelNode, int).
    assertThat(rel, instanceOf(LogicalFilter.class));
    final RelMetadataQuery mq = RelMetadataQuery.instance();
    assertThat(colType(mq, rel, 0), equalTo("DEPTNO-rel"));
    assertThat(colType(mq, rel, 1), equalTo("EXPR$1-rel"));
    // Next node is an aggregate. Its metadata uses
    // getColType(LogicalAggregate, int).
    final RelNode input = rel.getInput(0);
    assertThat(input, instanceOf(LogicalAggregate.class));
    assertThat(colType(mq, input, 0), equalTo("DEPTNO-agg"));
    // There is no caching. Another request causes another call to the provider.
    assertThat(buf.toString(), equalTo("[DEPTNO-rel, EXPR$1-rel, DEPTNO-agg]"));
    assertThat(buf.size(), equalTo(3));
    assertThat(colType(mq, input, 0), equalTo("DEPTNO-agg"));
    assertThat(buf.size(), equalTo(4));
    // Now add a cache. Only the first request for each piece of metadata
    // generates a new call to the provider.
    final RelOptPlanner planner = rel.getCluster().getPlanner();
    rel.getCluster().setMetadataProvider(new CachingRelMetadataProvider(rel.getCluster().getMetadataProvider(), planner));
    assertThat(colType(mq, input, 0), equalTo("DEPTNO-agg"));
    assertThat(buf.size(), equalTo(5));
    assertThat(colType(mq, input, 0), equalTo("DEPTNO-agg"));
    assertThat(buf.size(), equalTo(5));
    assertThat(colType(mq, input, 1), equalTo("EXPR$1-agg"));
    assertThat(buf.size(), equalTo(6));
    assertThat(colType(mq, input, 1), equalTo("EXPR$1-agg"));
    assertThat(buf.size(), equalTo(6));
    assertThat(colType(mq, input, 0), equalTo("DEPTNO-agg"));
    assertThat(buf.size(), equalTo(6));
    // With a different timestamp, a metadata item is re-computed on first call.
    long timestamp = planner.getRelMetadataTimestamp(rel);
    assertThat(timestamp, equalTo(0L));
    ((MockRelOptPlanner) planner).setRelMetadataTimestamp(timestamp + 1);
    assertThat(colType(mq, input, 0), equalTo("DEPTNO-agg"));
    assertThat(buf.size(), equalTo(7));
    assertThat(colType(mq, input, 0), equalTo("DEPTNO-agg"));
    assertThat(buf.size(), equalTo(7));
}