From d7ccb6d4a76f8c5346cd4c2e69d9d1244172d457 Mon Sep 17 00:00:00 2001 From: dnnanuti Date: Thu, 26 Jan 2023 10:46:29 +0000 Subject: [PATCH] Hive Connector with Amazon S3 documentation updates Add documentation for S3 Select pushdown related changes. --- presto-docs/src/main/sphinx/connector/hive.rst | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/presto-docs/src/main/sphinx/connector/hive.rst b/presto-docs/src/main/sphinx/connector/hive.rst index ab2829182cecd..c1bcd9c9a1f8d 100644 --- a/presto-docs/src/main/sphinx/connector/hive.rst +++ b/presto-docs/src/main/sphinx/connector/hive.rst @@ -487,7 +487,13 @@ Enabling S3 Select Pushdown You can enable S3 Select Pushdown using the ``s3_select_pushdown_enabled`` Hive session property or using the ``hive.s3select-pushdown.enabled`` configuration property. The session property will override the config -property, allowing you enable or disable on a per-query basis. +property, allowing you enable or disable on a per-query basis. Non-filtering +queries (``SELECT * FROM table``) are not pushed down to S3 Select, +as they retrieve the entire object content. + +For uncompressed files, S3 Select scans ranges of bytes in parallel. +The scan range requests run across the byte ranges of the internal +Hive splits for the query fragments pushed down to S3 Select. Understanding and Tuning the Maximum Connections ################################################