[CALCITE-1767] Fix join/aggregate rewriting rule when same table is referenced more than once

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Fix Version/s: 1.13.0
• Component/s: core
• Assignee: Jesus Camacho Rodriguez
• Reporter: Jesus Camacho Rodriguez
• Created: 28/Apr/17 09:51
• Updated: 26/Jun/17 08:29
• Resolved: 28/Apr/17 09:57

Description

Bug in new materialized view rewriting rule initially caught by coverity scan:

/core/src/main/java/org/apache/calcite/rel/rules/AbstractMaterializedViewRule.java: 950 in org.apache.calcite.rel.rules.AbstractMaterializedViewRule.generateTableMappings(com.google.common.collect.Multimap)()
944         }
945         result.add(HashBiMap.<RelTableRef, RelTableRef>create());
946         for (Entry<RelTableRef, Collection<RelTableRef>> e : multiMapTables.asMap().entrySet()) {
947           boolean added = false;
948           for (RelTableRef target : e.getValue()) {
949             if (added) {
    CID 144066:  API usage errors  (INVALIDATE_ITERATOR)
    Attempting to obtain another element from "result" after it's been modified.
950               for (BiMap<RelTableRef, RelTableRef> m : result) {
951                 final BiMap<RelTableRef, RelTableRef> newM =
952                     HashBiMap.<RelTableRef, RelTableRef>create(m);
953                 newM.put(e.getKey(), target);
954                 result.add(newM);
955               }

Issue Links

• is broken by: CALCITE-1731 Rewriting of queries using materialized views with joins and aggregates