[DOCS] Added a note in impala_scan_bytes_limit.xml - Added a note that queries can scan over the limit of this option at times.
Change-Id: Id20f952622ce553d9c1f47e469d97a3b4c19683f Reviewed-on: http://gerrit.cloudera.org:8080/11936 Tested-by: Impala Public Jenkins <impala-public-jenk...@cloudera.com> Reviewed-by: Bikramjeet Vig <bikramjeet....@cloudera.com> (cherry picked from commit a47b3b82c4288d324c3917c2b1a1f8a409958191) Project: http://git-wip-us.apache.org/repos/asf/impala/repo Commit: http://git-wip-us.apache.org/repos/asf/impala/commit/0d5b5d4e Tree: http://git-wip-us.apache.org/repos/asf/impala/tree/0d5b5d4e Diff: http://git-wip-us.apache.org/repos/asf/impala/diff/0d5b5d4e Branch: refs/heads/branch-3.1.0 Commit: 0d5b5d4ece423d910fae8ba6eb50f62929764857 Parents: f5348d4 Author: Alex Rodoni <arod...@cloudera.com> Authored: Thu Nov 15 13:08:41 2018 -0800 Committer: Zoltan Borok-Nagy <borokna...@cloudera.com> Committed: Tue Nov 27 11:59:28 2018 +0100 ---------------------------------------------------------------------- docs/topics/impala_scan_bytes_limit.xml | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/impala/blob/0d5b5d4e/docs/topics/impala_scan_bytes_limit.xml ---------------------------------------------------------------------- diff --git a/docs/topics/impala_scan_bytes_limit.xml b/docs/topics/impala_scan_bytes_limit.xml index 5fc4a8a..e67c971 100644 --- a/docs/topics/impala_scan_bytes_limit.xml +++ b/docs/topics/impala_scan_bytes_limit.xml @@ -20,8 +20,7 @@ under the License. <!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd"> <concept id="scan_bytes_limit"> - <title>SCAN_BYTES_LIMIT Query Option (<keyword keyref="impala31"/> or higher - only)</title> + <title>SCAN_BYTES_LIMIT Query Option (<keyword keyref="impala31"/> or higher only)</title> <titlealts audience="PDF"> @@ -44,8 +43,8 @@ under the License. <conbody> <p> - The <codeph>SCAN_BYTES_LIMIT</codeph> query option sets a time limit on the bytes scanned - by HDFS and HBase SCAN operations. If a query is still executing when the queryâs + The <codeph>SCAN_BYTES_LIMIT</codeph> query option sets a limit on the bytes scanned by + HDFS and HBase SCAN operations. If a query is still executing when the queryâs coordinator detects that it has exceeded the limit, the query is terminated with an error. The option is intended to prevent runaway queries that scan more data than is intended. </p> @@ -60,7 +59,7 @@ under the License. Admission Control and Query Queuing</xref> for information about default query options). If a user accidentally omits a partition filter in a <codeph>WHERE</codeph> clause and runs a large query that scans a lot of data, the query will be automatically terminated - after the time limit expires to free up resources. + after it scans more data than the <codeph>SCAN_BYTES_LIMIT</codeph>. </p> <p> @@ -89,6 +88,10 @@ under the License. </p> <p> + Because the checks are done periodically, the query may scan over the limit at times. + </p> + + <p> <b>Syntax:</b> <codeph>SET SCAN_BYTES_LIMIT=bytes;</codeph> </p>
