Support explain verification

Add a new functionality to the verifier to allow explain verification.

For each query pairs to be verified, explain both control and test, and
compare the query plans. Verification is marked as succeeded as long as
the test query can be explained.

Introduced a new field matchType in the output event, which can be used
to indicate whether there is plan difference.

For non-DML queries, we don't care much about plan difference and hence
the control query and plan comparison are skipped.

presto-docs/src/main/sphinx/admin/verifier.rst

@@ -182,6 +182,17 @@ automatically resolve certain mismatches.
 * **Resolved Functions**: In the case of a results mismatch, if the query uses a function in a
     specified list, the test case is marked as resolved.
 
+Explain Mode
+------------
+In explain mode, Verifier checks whether source queries can be explained instead of whether
+they produces the same results. Verification is marked as succeeded when both control query
+and test query can be explained.
+
+The field ``matchType`` in the output event can be used as an indicator whether there are
+plan differences between the control run and the test run.
+
+For non-DML queries, the control query and the plan comparison are skipped.
+
 Extending Verifier
 ------------------
 

presto-verifier/src/main/java/com/facebook/presto/verifier/event/QueryInfo.java

@@ -44,6 +44,7 @@ public class QueryInfo
     private final List<String> setupQueries;
     private final List<String> teardownQueries;
     private final String checksumQuery;
+    private final String jsonPlan;
 
     private final Double cpuTimeSecs;
     private final Double wallTimeSecs;
@@ -52,25 +53,6 @@ public class QueryInfo
 
     private final String extraStats;
 
-    public QueryInfo(
-            String catalog,
-            String schema,
-            String originalQuery)
-    {
-        this(
-                catalog,
-                schema,
-                originalQuery,
-                ImmutableList.of(),
-                ImmutableList.of(),
-                Optional.empty(),
-                Optional.empty(),
-                Optional.empty(),
-                Optional.empty(),
-                Optional.empty(),
-                Optional.empty());
-    }
-
     public QueryInfo(
             String catalog,
             String schema,
@@ -82,6 +64,7 @@ public QueryInfo(
             Optional<List<String>> setupQueries,
             Optional<List<String>> teardownQueries,
             Optional<String> checksumQuery,
+            Optional<String> jsonPlan,
             Optional<QueryActionStats> queryActionStats)
     {
         Optional<QueryStats> stats = queryActionStats.flatMap(QueryActionStats::getQueryStats);
@@ -96,6 +79,7 @@ public QueryInfo(
         this.setupQueries = setupQueries.orElse(null);
         this.teardownQueries = teardownQueries.orElse(null);
         this.checksumQuery = checksumQuery.orElse(null);
+        this.jsonPlan = jsonPlan.orElse(null);
         this.cpuTimeSecs = stats.map(QueryStats::getCpuTimeMillis).map(QueryInfo::millisToSeconds).orElse(null);
         this.wallTimeSecs = stats.map(QueryStats::getWallTimeMillis).map(QueryInfo::millisToSeconds).orElse(null);
         this.peakTotalMemoryBytes = stats.map(QueryStats::getPeakTotalMemoryBytes).orElse(null);
@@ -174,6 +158,12 @@ public String getChecksumQuery()
         return checksumQuery;
     }
 
+    @EventField
+    public String getJsonPlan()
+    {
+        return jsonPlan;
+    }
+
     @EventField
     public Double getCpuTimeSecs()
     {
@@ -203,4 +193,103 @@ public String getExtraStats()
     {
         return extraStats;
     }
+
+    public static Builder builder(String catalog, String schema, String originalQuery)
+    {
+        return new Builder(catalog, schema, originalQuery);
+    }
+
+    public static class Builder
+    {
+        private final String catalog;
+        private final String schema;
+        private final String originalQuery;
+        private List<String> setupQueryIds = ImmutableList.of();
+        private List<String> teardownQueryIds = ImmutableList.of();
+        private Optional<String> checksumQueryId = Optional.empty();
+        private Optional<String> query = Optional.empty();
+        private Optional<List<String>> setupQueries = Optional.empty();
+        private Optional<List<String>> teardownQueries = Optional.empty();
+        private Optional<String> checksumQuery = Optional.empty();
+        private Optional<String> jsonPlan = Optional.empty();
+        private Optional<QueryActionStats> queryActionStats = Optional.empty();
+
+        private Builder(String catalog, String schema, String originalQuery)
+        {
+            this.catalog = requireNonNull(catalog, "catalog is null");
+            this.schema = requireNonNull(schema, "schema is null");
+            this.originalQuery = requireNonNull(originalQuery, "originalQuery is null");
+        }
+
+        public Builder setSetupQueryIds(List<String> setupQueryIds)
+        {
+            this.setupQueryIds = ImmutableList.copyOf(setupQueryIds);
+            return this;
+        }
+
+        public Builder setTeardownQueryIds(List<String> teardownQueryIds)
+        {
+            this.teardownQueryIds = ImmutableList.copyOf(teardownQueryIds);
+            return this;
+        }
+
+        public Builder setChecksumQueryId(Optional<String> checksumQueryId)
+        {
+            this.checksumQueryId = requireNonNull(checksumQueryId, "checksumQueryId is null");
+            return this;
+        }
+
+        public Builder setQuery(Optional<String> query)
+        {
+            this.query = requireNonNull(query, "query is null");
+            return this;
+        }
+
+        public Builder setSetupQueries(Optional<List<String>> setupQueries)
+        {
+            this.setupQueries = requireNonNull(setupQueries, "setupQueries is null");
+            return this;
+        }
+
+        public Builder setTeardownQueries(Optional<List<String>> teardownQueries)
+        {
+            this.teardownQueries = requireNonNull(teardownQueries, "teardownQueries is null");
+            return this;
+        }
+
+        public Builder setChecksumQuery(Optional<String> checksumQuery)
+        {
+            this.checksumQuery = requireNonNull(checksumQuery, "checksumQuery is null");
+            return this;
+        }
+
+        public Builder setJsonPlan(String jsonPlan)
+        {
+            this.jsonPlan = Optional.of(jsonPlan);
+            return this;
+        }
+
+        public Builder setQueryActionStats(Optional<QueryActionStats> queryActionStats)
+        {
+            this.queryActionStats = requireNonNull(queryActionStats, "queryActionStats is null");
+            return this;
+        }
+
+        public QueryInfo build()
+        {
+            return new QueryInfo(
+                    catalog,
+                    schema,
+                    originalQuery,
+                    setupQueryIds,
+                    teardownQueryIds,
+                    checksumQueryId,
+                    query,
+                    setupQueries,
+                    teardownQueries,
+                    checksumQuery,
+                    jsonPlan,
+                    queryActionStats);
+        }
+    }
 }

presto-verifier/src/main/java/com/facebook/presto/verifier/event/VerifierQueryEvent.java

@@ -46,6 +46,7 @@ public enum EventStatus
     private final String name;
 
     private final String status;
+    private final String matchType;
     private final String skippedReason;
 
     private final String determinismAnalysis;
@@ -68,6 +69,7 @@ public VerifierQueryEvent(
             String testId,
             String name,
             EventStatus status,
+            Optional<String> matchType,
             Optional<SkippedReason> skippedReason,
             Optional<DeterminismAnalysisDetails> determinismAnalysisDetails,
             Optional<String> resolveMessage,
@@ -83,6 +85,7 @@ public VerifierQueryEvent(
         this.testId = requireNonNull(testId, "testId is null");
         this.name = requireNonNull(name, "name is null");
         this.status = status.name();
+        this.matchType = matchType.orElse(null);
         this.skippedReason = skippedReason.map(SkippedReason::name).orElse(null);
         this.determinismAnalysis = determinismAnalysisDetails.map(DeterminismAnalysisDetails::getResult).orElse(null);
         this.determinismAnalysisDetails = determinismAnalysisDetails.orElse(null);
@@ -108,19 +111,20 @@ public static VerifierQueryEvent skipped(
                 testId,
                 sourceQuery.getName(),
                 SKIPPED,
+                Optional.empty(),
                 Optional.of(skippedReason),
                 Optional.empty(),
                 Optional.empty(),
                 skipControl ?
                         Optional.empty() :
-                        Optional.of(new QueryInfo(
+                        Optional.of(QueryInfo.builder(
                                 sourceQuery.getControlConfiguration().getCatalog(),
                                 sourceQuery.getControlConfiguration().getSchema(),
-                                sourceQuery.getQuery(CONTROL))),
-                new QueryInfo(
+                                sourceQuery.getQuery(CONTROL)).build()),
+                QueryInfo.builder(
                         sourceQuery.getTestConfiguration().getCatalog(),
                         sourceQuery.getTestConfiguration().getSchema(),
-                        sourceQuery.getQuery(TEST)),
+                        sourceQuery.getQuery(TEST)).build(),
                 Optional.empty(),
                 Optional.empty(),
                 Optional.empty(),
@@ -152,6 +156,12 @@ public String getStatus()
         return status;
     }
 
+    @EventField
+    public String getMatchType()
+    {
+        return matchType;
+    }
+
     @EventField
     public String getSkippedReason()
     {