jon-wei commented on a change in pull request #9516: More efficient join filter
rewrites
URL: https://github.com/apache/druid/pull/9516#discussion_r393376432
##########
File path:
processing/src/main/java/org/apache/druid/segment/join/filter/JoinFilterAnalyzer.java
##########
@@ -462,45 +559,14 @@ private static String
getCorrelatedBaseExprVirtualColumnName(int counter)
return clauseForFilteredTable.getJoinable().getCorrelatedColumnValues(
filterColumnNoPrefix,
filterValue,
- correlatedColumnNoPrefix
+ correlatedColumnNoPrefix,
+ filterRewriteMaxSize,
+ enableRewriteValueColumnFilters
);
}
- /**
- * For each rhs column that appears in the equiconditions for a table's
JoinableClause,
- * we try to determine what base table columns are related to the rhs column
through the total set of equiconditions.
- * We do this by searching backwards through the chain of join
equiconditions using the provided equicondition map.
- *
- * For example, suppose we have 3 tables, A,B,C, joined with the following
conditions, where A is the base table:
- * A.joinColumn == B.joinColumn
- * B.joinColum == C.joinColumn
- *
- * We would determine that C.joinColumn is correlated with A.joinColumn: we
first see that
- * C.joinColumn is linked to B.joinColumn which in turn is linked to
A.joinColumn
- *
- * Suppose we had the following join conditions instead:
- * f(A.joinColumn) == B.joinColumn
- * B.joinColum == C.joinColumn
- * In this case, the JoinFilterColumnCorrelationAnalysis for C.joinColumn
would be linked to f(A.joinColumn).
- *
- * Suppose we had the following join conditions instead:
- * A.joinColumn == B.joinColumn
- * f(B.joinColum) == C.joinColumn
- *
- * Because we cannot reverse the function f() applied to the second table B
in all cases,
- * we cannot relate C.joinColumn to A.joinColumn, and we would not generate
a correlation for C.joinColumn
- *
- * @param baseColumnNames Set of names of columns that belong to the
base table, including pre-join virtual
- * columns
- * @param tablePrefix Prefix for a join table
- * @param clauseForTablePrefix Joinable clause for the prefix
- * @param equiConditions Map of equiconditions, keyed by the right
hand columns
- *
- * @return A list of correlatation analyses for the equicondition RHS
columns that reside in the table associated with
- * the tablePrefix
- */
- private static Optional<List<JoinFilterColumnCorrelationAnalysis>>
findCorrelatedBaseTableColumns(
- Set<String> baseColumnNames,
+ private static Optional<Map<String, JoinFilterColumnCorrelationAnalysis>>
findCorrelatedBaseTableColumns(
Review comment:
Whoops, restored the missing javadocs
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