pvary commented on a change in pull request #538: HIVE-21217: Optimize range
calculation for PTF
URL: https://github.com/apache/hive/pull/538#discussion_r257278647
##########
File path:
ql/src/java/org/apache/hadoop/hive/ql/udf/ptf/ValueBoundaryScanner.java
##########
@@ -44,10 +49,207 @@ public ValueBoundaryScanner(BoundaryDef start,
BoundaryDef end, boolean nullsLas
this.nullsLast = nullsLast;
}
+ public abstract Object computeValue(Object row) throws HiveException;
+
+ /**
+ * Checks if the distance of v2 to v1 is greater than the given amt.
+ * @return True if the value of v1 - v2 is greater than amt or either value
is null.
+ */
+ public abstract boolean isDistanceGreater(Object v1, Object v2, int amt);
+
+ /**
+ * Checks if the values of v1 or v2 are the same.
+ * @return True if both values are the same or both are nulls.
+ */
+ public abstract boolean isEqual(Object v1, Object v2);
+
public abstract int computeStart(int rowIdx, PTFPartition p) throws
HiveException;
public abstract int computeEnd(int rowIdx, PTFPartition p) throws
HiveException;
+ /**
+ * Checks and maintains cache content - optimizes cache window to always be
around current row
+ * thereby makes it follow the current progress.
+ * @param rowIdx current row
+ * @param p current partition for the PTF operator
+ * @throws HiveException
+ */
+ public void handleCache(int rowIdx, PTFPartition p) throws HiveException {
+ BoundaryCache cache = p.getBoundaryCache();
+ if (cache == null) {
+ return;
+ }
+
+ //Start of partition
+ if (rowIdx == 0) {
+ cache.clear();
+ }
+ if (cache.isComplete()) {
+ return;
+ }
+
+ int cachePos = cache.approxCachePositionOf(rowIdx);
+
+ if (cache.isEmpty()) {
+ fillCacheUntilEndOrFull(rowIdx, p);
+ } else if (cachePos > 50 && cachePos <= 75) {
Review comment:
This is strange to me. Do we know the size of the window in advance? Shall
we not use our cache accordingly? If the window size is 5 then we should cache
the 7 values (1 before, 1 after, and the 5 values)?
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