Github user zellerh commented on a diff in the pull request:
https://github.com/apache/incubator-trafodion/pull/255#discussion_r49487630
--- Diff: core/sql/generator/GenPreCode.cpp ---
@@ -11274,6 +11274,485 @@ short
HbaseAccess::extractHbaseFilterPreds(Generator * generator,
return 0;
}
+////////////////////////////////////////////////////////////////////////////
+// To push down, the predicate must have the following form:
+// xp:= <column> <op> <value-expr>
+// xp:= <column> is not null (no support for hbase lookup)
+// xp:= <column> is null (no support for hbase lookup)
+// (xp:=<column> like <value-expr> not yet implemented)
+// xp:=<xp> OR <xp> (not evaluated in isHbaseFilterPredV2, but by
extractHbaseFilterPredV2)
+// xp:=<xp> AND <xp>(not evaluated in isHbaseFilterPredV2, but by
extractHbaseFilterPredV2)
+//
+// and all of the following conditions must be met:
+//
+// <column>: a base table or index column which can be
serialized and belong to the table being scanned.
+// serialized: either the column doesn't need
encoding, like
+// an unsigned integer, or the
column
+// was declared with the
SERIALIZED option.
+// it also must not be an added
column with default non null.
+// <op>: eq, ne, gt, ge, lt, le
+// <value-expr>: an expression that only contains const or param
values, and
+// <value-expr>'s datatype is not a superset of
<column>'s datatype.
+//
+/////////////////////////////////////////////////////////////////////////////
+NABoolean HbaseAccess::isHbaseFilterPredV2(Generator * generator, ItemExpr
* ie,
+ ValueId &colVID, ValueId &valueVID,
+ NAString &op)
+{
+ NABoolean foundBinary = FALSE;
+ NABoolean foundUnary = FALSE;
+ NABoolean hbaseLookupPred = FALSE;
+ NABoolean flipOp = FALSE; // set to TRUE when column is child(1)
+
+ if (ie &&
+ ((ie->getOperatorType() >= ITM_EQUAL) &&
+ (ie->getOperatorType() <= ITM_GREATER_EQ))) //binary operator case
+ {//begin expression
+ ItemExpr * child0 = ie->child(0)->castToItemExpr();
+ ItemExpr * child1 = ie->child(1)->castToItemExpr();
+
+ if ((ie->child(0)->getOperatorType() == ITM_BASECOLUMN) &&
+ (NOT hasColReference(ie->child(1))))
--- End diff --
hasColReference() does not filter out functions. I think it would return
FALSE for expressions like sin(0.5) or ? + 3 > 10. If we generate an expression
to compute this value before passing it to the filter then that's ok. I didn't
see that code generation in your change, probably it is already done in the
existing V1 logic.
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