[GitHub] [arrow] pitrou commented on a diff in pull request #14545: PARQUET-2209: [parquet-cpp] Optimize skip for the case that number of values to skip equals page size

[GitBox]

pitrou commented on code in PR #14545:
URL: https://github.com/apache/arrow/pull/14545#discussion_r1009618889


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cpp/src/parquet/column_reader.cc:
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@@ -1141,12 +1146,14 @@ int64_t TypedColumnReaderImpl<DType>::ReadBatchSpaced(
 template <typename DType>
 int64_t TypedColumnReaderImpl<DType>::Skip(int64_t num_values_to_skip) {
   int64_t values_to_skip = num_values_to_skip;
-  while (HasNext() && values_to_skip > 0) {
+  // Optimization: Do not call HasNext() when values_to_skip == 0.
+  while (values_to_skip > 0 && HasNext()) {

Review Comment:
   Just to be clear: this is the crux of the optimization, right?



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