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Posted to commits@impala.apache.org by jr...@apache.org on 2017/11/13 23:26:54 UTC
[4/7] incubator-impala git commit: Update Impala docs for 2.10 release
http://git-wip-us.apache.org/repos/asf/incubator-impala/blob/ca9005be/docs/build/html/topics/impala_hbase.html
----------------------------------------------------------------------
diff --git a/docs/build/html/topics/impala_hbase.html b/docs/build/html/topics/impala_hbase.html
index 7ee8bad..7112f90 100644
--- a/docs/build/html/topics/impala_hbase.html
+++ b/docs/build/html/topics/impala_hbase.html
@@ -612,6 +612,15 @@ set hbase_caching=1000;
The <code class="ph codeph">LOAD DATA</code> statement cannot be used with HBase tables.
</p>
</li>
+ <li class="li">
+ <p class="p">
+ The <code class="ph codeph">TABLESAMPLE</code> clause of the <code class="ph codeph">SELECT</code>
+ statement does not apply to a table reference derived from a view, a subquery,
+ or anything other than a real base table. This clause only works for tables
+ backed by HDFS or HDFS-like data files, therefore it does not apply to Kudu or
+ HBase tables.
+ </p>
+ </li>
</ul>
</div>
</article>
http://git-wip-us.apache.org/repos/asf/incubator-impala/blob/ca9005be/docs/build/html/topics/impala_hints.html
----------------------------------------------------------------------
diff --git a/docs/build/html/topics/impala_hints.html b/docs/build/html/topics/impala_hints.html
index f2b48f0..19bd16d 100644
--- a/docs/build/html/topics/impala_hints.html
+++ b/docs/build/html/topics/impala_hints.html
@@ -111,11 +111,19 @@ INSERT <var class="keyword varname">insert_clauses</var>
<p class="p">
With both forms of hint syntax, include the <code class="ph codeph">STRAIGHT_JOIN</code>
- keyword immediately after the <code class="ph codeph">SELECT</code> keyword to prevent Impala from
+ keyword immediately after the <code class="ph codeph">SELECT</code> and any
+ <code class="ph codeph">DISTINCT</code> or <code class="ph codeph">ALL</code> keywords to prevent Impala from
reordering the tables in a way that makes the join-related hints ineffective.
</p>
<p class="p">
+ The <code class="ph codeph">STRAIGHT_JOIN</code> hint affects the join order of table references in the query
+ block containing the hint. It does not affect the join order of nested queries, such as views,
+ inline views, or <code class="ph codeph">WHERE</code>-clause subqueries. To use this hint for performance
+ tuning of complex queries, apply the hint to all query blocks that need a fixed join order.
+ </p>
+
+ <p class="p">
To reduce the need to use hints, run the <code class="ph codeph">COMPUTE STATS</code> statement against all tables involved
in joins, or used as the source tables for <code class="ph codeph">INSERT ... SELECT</code> operations where the
destination is a partitioned Parquet table. Do this operation after loading data or making substantial
http://git-wip-us.apache.org/repos/asf/incubator-impala/blob/ca9005be/docs/build/html/topics/impala_incompatible_changes.html
----------------------------------------------------------------------
diff --git a/docs/build/html/topics/impala_incompatible_changes.html b/docs/build/html/topics/impala_incompatible_changes.html
index 9623ba1..d968e2b 100644
--- a/docs/build/html/topics/impala_incompatible_changes.html
+++ b/docs/build/html/topics/impala_incompatible_changes.html
@@ -23,9 +23,25 @@
<p class="p toc inpage"></p>
</div>
- <nav role="navigation" class="related-links"><div class="familylinks"><div class="parentlink"><strong>Parent topic:</strong> <a class="link" href="../topics/impala_release_notes.html">Impala Release Notes</a></div></div></nav><article class="topic concept nested1" aria-labelledby="ariaid-title2" id="incompatible_changes__incompatible_changes_29x">
+ <nav role="navigation" class="related-links"><div class="familylinks"><div class="parentlink"><strong>Parent topic:</strong> <a class="link" href="../topics/impala_release_notes.html">Impala Release Notes</a></div></div></nav><article class="topic concept nested1" aria-labelledby="ariaid-title2" id="incompatible_changes__incompatible_changes_210x">
- <h2 class="title topictitle2" id="ariaid-title2">Incompatible Changes Introduced in Impala 2.9.x</h2>
+ <h2 class="title topictitle2" id="ariaid-title2">Incompatible Changes Introduced in Impala 2.10.x</h2>
+
+ <div class="body conbody">
+
+ <p class="p">
+ For the full list of issues closed in this release, including any that introduce
+ behavior changes or incompatibilities, see the
+ <a class="xref" href="https://impala.incubator.apache.org/docs/changelog-2.10.html" target="_blank">changelog for <span class="keyword">Impala 2.10</span></a>.
+ </p>
+
+ </div>
+
+ </article>
+
+ <article class="topic concept nested1" aria-labelledby="ariaid-title3" id="incompatible_changes__incompatible_changes_29x">
+
+ <h2 class="title topictitle2" id="ariaid-title3">Incompatible Changes Introduced in Impala 2.9.x</h2>
<div class="body conbody">
@@ -41,9 +57,9 @@
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title3" id="incompatible_changes__incompatible_changes_28x">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title4" id="incompatible_changes__incompatible_changes_28x">
- <h2 class="title topictitle2" id="ariaid-title3">Incompatible Changes Introduced in Impala 2.8.x</h2>
+ <h2 class="title topictitle2" id="ariaid-title4">Incompatible Changes Introduced in Impala 2.8.x</h2>
<div class="body conbody">
<ul class="ul">
@@ -134,9 +150,9 @@
</div>
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title4" id="incompatible_changes__incompatible_changes_27x">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title5" id="incompatible_changes__incompatible_changes_27x">
- <h2 class="title topictitle2" id="ariaid-title4">Incompatible Changes Introduced in Impala 2.7.x</h2>
+ <h2 class="title topictitle2" id="ariaid-title5">Incompatible Changes Introduced in Impala 2.7.x</h2>
<div class="body conbody">
<ul class="ul">
@@ -158,9 +174,9 @@
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title5" id="incompatible_changes__incompatible_changes_26x">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title6" id="incompatible_changes__incompatible_changes_26x">
- <h2 class="title topictitle2" id="ariaid-title5">Incompatible Changes Introduced in Impala 2.6.x</h2>
+ <h2 class="title topictitle2" id="ariaid-title6">Incompatible Changes Introduced in Impala 2.6.x</h2>
<div class="body conbody">
<ul class="ul">
@@ -307,9 +323,9 @@
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title6" id="incompatible_changes__incompatible_changes_25x">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title7" id="incompatible_changes__incompatible_changes_25x">
- <h2 class="title topictitle2" id="ariaid-title6">Incompatible Changes Introduced in Impala 2.5.x</h2>
+ <h2 class="title topictitle2" id="ariaid-title7">Incompatible Changes Introduced in Impala 2.5.x</h2>
<div class="body conbody">
<ul class="ul">
@@ -395,9 +411,9 @@
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title7" id="incompatible_changes__incompatible_changes_24x">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title8" id="incompatible_changes__incompatible_changes_24x">
- <h2 class="title topictitle2" id="ariaid-title7">Incompatible Changes Introduced in Impala 2.4.x</h2>
+ <h2 class="title topictitle2" id="ariaid-title8">Incompatible Changes Introduced in Impala 2.4.x</h2>
<div class="body conbody">
<p class="p">
@@ -412,9 +428,9 @@
- <article class="topic concept nested1" aria-labelledby="ariaid-title8" id="incompatible_changes__incompatible_changes_23x">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title9" id="incompatible_changes__incompatible_changes_23x">
- <h2 class="title topictitle2" id="ariaid-title8">Incompatible Changes Introduced in Impala 2.3.x</h2>
+ <h2 class="title topictitle2" id="ariaid-title9">Incompatible Changes Introduced in Impala 2.3.x</h2>
<div class="body conbody">
@@ -482,9 +498,9 @@
- <article class="topic concept nested1" aria-labelledby="ariaid-title9" id="incompatible_changes__incompatible_changes_22x">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title10" id="incompatible_changes__incompatible_changes_22x">
- <h2 class="title topictitle2" id="ariaid-title9">Incompatible Changes Introduced in Impala 2.2.x</h2>
+ <h2 class="title topictitle2" id="ariaid-title10">Incompatible Changes Introduced in Impala 2.2.x</h2>
<div class="body conbody">
@@ -527,9 +543,9 @@
- <article class="topic concept nested1" aria-labelledby="ariaid-title10" id="incompatible_changes__incompatible_changes_21x">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title11" id="incompatible_changes__incompatible_changes_21x">
- <h2 class="title topictitle2" id="ariaid-title10">Incompatible Changes Introduced in Impala 2.1.x</h2>
+ <h2 class="title topictitle2" id="ariaid-title11">Incompatible Changes Introduced in Impala 2.1.x</h2>
<div class="body conbody">
@@ -572,9 +588,9 @@
- <article class="topic concept nested1" aria-labelledby="ariaid-title11" id="incompatible_changes__incompatible_changes_205">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title12" id="incompatible_changes__incompatible_changes_205">
- <h2 class="title topictitle2" id="ariaid-title11">Incompatible Changes Introduced in Impala 2.0.5</h2>
+ <h2 class="title topictitle2" id="ariaid-title12">Incompatible Changes Introduced in Impala 2.0.5</h2>
<div class="body conbody">
@@ -585,9 +601,9 @@
</div>
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title12" id="incompatible_changes__incompatible_changes_204">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title13" id="incompatible_changes__incompatible_changes_204">
- <h2 class="title topictitle2" id="ariaid-title12">Incompatible Changes Introduced in Impala 2.0.4</h2>
+ <h2 class="title topictitle2" id="ariaid-title13">Incompatible Changes Introduced in Impala 2.0.4</h2>
<div class="body conbody">
@@ -598,18 +614,18 @@
</div>
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title13" id="incompatible_changes__incompatible_changes_203">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title14" id="incompatible_changes__incompatible_changes_203">
- <h2 class="title topictitle2" id="ariaid-title13">Incompatible Changes Introduced in Impala 2.0.3</h2>
+ <h2 class="title topictitle2" id="ariaid-title14">Incompatible Changes Introduced in Impala 2.0.3</h2>
<div class="body conbody">
</div>
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title14" id="incompatible_changes__incompatible_changes_202">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title15" id="incompatible_changes__incompatible_changes_202">
- <h2 class="title topictitle2" id="ariaid-title14">Incompatible Changes Introduced in Impala 2.0.2</h2>
+ <h2 class="title topictitle2" id="ariaid-title15">Incompatible Changes Introduced in Impala 2.0.2</h2>
<div class="body conbody">
@@ -620,9 +636,9 @@
</div>
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title15" id="incompatible_changes__incompatible_changes_201">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title16" id="incompatible_changes__incompatible_changes_201">
- <h2 class="title topictitle2" id="ariaid-title15">Incompatible Changes Introduced in Impala 2.0.1</h2>
+ <h2 class="title topictitle2" id="ariaid-title16">Incompatible Changes Introduced in Impala 2.0.1</h2>
<div class="body conbody">
@@ -659,9 +675,9 @@
</div>
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title16" id="incompatible_changes__incompatible_changes_200">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title17" id="incompatible_changes__incompatible_changes_200">
- <h2 class="title topictitle2" id="ariaid-title16">Incompatible Changes Introduced in Impala 2.0.0</h2>
+ <h2 class="title topictitle2" id="ariaid-title17">Incompatible Changes Introduced in Impala 2.0.0</h2>
<div class="body conbody">
@@ -855,8 +871,8 @@
</div>
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title17" id="incompatible_changes__incompatible_changes_144">
- <h2 class="title topictitle2" id="ariaid-title17">Incompatible Changes Introduced in Impala 1.4.4</h2>
+ <article class="topic concept nested1" aria-labelledby="ariaid-title18" id="incompatible_changes__incompatible_changes_144">
+ <h2 class="title topictitle2" id="ariaid-title18">Incompatible Changes Introduced in Impala 1.4.4</h2>
<div class="body conbody">
<p class="p">
No incompatible changes.
@@ -865,9 +881,9 @@
</div>
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title18" id="incompatible_changes__incompatible_changes_143">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title19" id="incompatible_changes__incompatible_changes_143">
- <h2 class="title topictitle2" id="ariaid-title18">Incompatible Changes Introduced in Impala 1.4.3</h2>
+ <h2 class="title topictitle2" id="ariaid-title19">Incompatible Changes Introduced in Impala 1.4.3</h2>
<div class="body conbody">
@@ -879,9 +895,9 @@
</div>
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title19" id="incompatible_changes__incompatible_changes_142">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title20" id="incompatible_changes__incompatible_changes_142">
- <h2 class="title topictitle2" id="ariaid-title19">Incompatible Changes Introduced in Impala 1.4.2</h2>
+ <h2 class="title topictitle2" id="ariaid-title20">Incompatible Changes Introduced in Impala 1.4.2</h2>
<div class="body conbody">
@@ -892,9 +908,9 @@
</div>
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title20" id="incompatible_changes__incompatible_changes_141">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title21" id="incompatible_changes__incompatible_changes_141">
- <h2 class="title topictitle2" id="ariaid-title20">Incompatible Changes Introduced in Impala 1.4.1</h2>
+ <h2 class="title topictitle2" id="ariaid-title21">Incompatible Changes Introduced in Impala 1.4.1</h2>
<div class="body conbody">
@@ -904,9 +920,9 @@
</div>
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title21" id="incompatible_changes__incompatible_changes_140">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title22" id="incompatible_changes__incompatible_changes_140">
- <h2 class="title topictitle2" id="ariaid-title21">Incompatible Changes Introduced in Impala 1.4.0</h2>
+ <h2 class="title topictitle2" id="ariaid-title22">Incompatible Changes Introduced in Impala 1.4.0</h2>
<div class="body conbody">
@@ -1004,9 +1020,9 @@
</div>
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title22" id="incompatible_changes__incompatible_changes_133">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title23" id="incompatible_changes__incompatible_changes_133">
- <h2 class="title topictitle2" id="ariaid-title22">Incompatible Changes Introduced in Impala 1.3.3</h2>
+ <h2 class="title topictitle2" id="ariaid-title23">Incompatible Changes Introduced in Impala 1.3.3</h2>
<div class="body conbody">
@@ -1018,9 +1034,9 @@
</div>
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title23" id="incompatible_changes__incompatible_changes_132">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title24" id="incompatible_changes__incompatible_changes_132">
- <h2 class="title topictitle2" id="ariaid-title23">Incompatible Changes Introduced in Impala 1.3.2</h2>
+ <h2 class="title topictitle2" id="ariaid-title24">Incompatible Changes Introduced in Impala 1.3.2</h2>
<div class="body conbody">
@@ -1031,9 +1047,9 @@
</div>
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title24" id="incompatible_changes__incompatible_changes_131">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title25" id="incompatible_changes__incompatible_changes_131">
- <h2 class="title topictitle2" id="ariaid-title24">Incompatible Changes Introduced in Impala 1.3.1</h2>
+ <h2 class="title topictitle2" id="ariaid-title25">Incompatible Changes Introduced in Impala 1.3.1</h2>
<div class="body conbody">
@@ -1061,9 +1077,9 @@
</div>
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title25" id="incompatible_changes__incompatible_changes_130">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title26" id="incompatible_changes__incompatible_changes_130">
- <h2 class="title topictitle2" id="ariaid-title25">Incompatible Changes Introduced in Impala 1.3.0</h2>
+ <h2 class="title topictitle2" id="ariaid-title26">Incompatible Changes Introduced in Impala 1.3.0</h2>
<div class="body conbody">
@@ -1148,9 +1164,9 @@
</div>
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title26" id="incompatible_changes__incompatible_changes_124">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title27" id="incompatible_changes__incompatible_changes_124">
- <h2 class="title topictitle2" id="ariaid-title26">Incompatible Changes Introduced in Impala 1.2.4</h2>
+ <h2 class="title topictitle2" id="ariaid-title27">Incompatible Changes Introduced in Impala 1.2.4</h2>
<div class="body conbody">
@@ -1170,9 +1186,9 @@
</div>
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title27" id="incompatible_changes__incompatible_changes_123">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title28" id="incompatible_changes__incompatible_changes_123">
- <h2 class="title topictitle2" id="ariaid-title27">Incompatible Changes Introduced in Impala 1.2.3</h2>
+ <h2 class="title topictitle2" id="ariaid-title28">Incompatible Changes Introduced in Impala 1.2.3</h2>
<div class="body conbody">
@@ -1184,9 +1200,9 @@
</div>
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title28" id="incompatible_changes__incompatible_changes_122">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title29" id="incompatible_changes__incompatible_changes_122">
- <h2 class="title topictitle2" id="ariaid-title28">Incompatible Changes Introduced in Impala 1.2.2</h2>
+ <h2 class="title topictitle2" id="ariaid-title29">Incompatible Changes Introduced in Impala 1.2.2</h2>
<div class="body conbody">
@@ -1252,9 +1268,9 @@ select * from `cross`;</code></pre>
</div>
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title29" id="incompatible_changes__incompatible_changes_121">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title30" id="incompatible_changes__incompatible_changes_121">
- <h2 class="title topictitle2" id="ariaid-title29">Incompatible Changes Introduced in Impala 1.2.1</h2>
+ <h2 class="title topictitle2" id="ariaid-title30">Incompatible Changes Introduced in Impala 1.2.1</h2>
<div class="body conbody">
@@ -1321,9 +1337,9 @@ select * from `cross`;</code></pre>
</div>
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title30" id="incompatible_changes__incompatible_changes_120">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title31" id="incompatible_changes__incompatible_changes_120">
- <h2 class="title topictitle2" id="ariaid-title30">Incompatible Changes Introduced in Impala 1.2.0 (Beta)</h2>
+ <h2 class="title topictitle2" id="ariaid-title31">Incompatible Changes Introduced in Impala 1.2.0 (Beta)</h2>
<div class="body conbody">
@@ -1377,9 +1393,9 @@ select * from `cross`;</code></pre>
</div>
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title31" id="incompatible_changes__incompatible_changes_111">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title32" id="incompatible_changes__incompatible_changes_111">
- <h2 class="title topictitle2" id="ariaid-title31">Incompatible Changes Introduced in Impala 1.1.1</h2>
+ <h2 class="title topictitle2" id="ariaid-title32">Incompatible Changes Introduced in Impala 1.1.1</h2>
<div class="body conbody">
@@ -1427,9 +1443,9 @@ ALTER TABLE <var class="keyword varname">table_name</var> SET FILEFORMAT
</div>
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title32" id="incompatible_changes__incompatible_changes_11">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title33" id="incompatible_changes__incompatible_changes_11">
- <h2 class="title topictitle2" id="ariaid-title32">Incompatible Change Introduced in Impala 1.1</h2>
+ <h2 class="title topictitle2" id="ariaid-title33">Incompatible Change Introduced in Impala 1.1</h2>
<div class="body conbody">
@@ -1454,9 +1470,9 @@ ALTER TABLE <var class="keyword varname">table_name</var> SET FILEFORMAT
</div>
</article>
- <article class="topic concept nested1" aria-labelledby="ariaid-title33" id="incompatible_changes__incompatible_changes_10">
+ <article class="topic concept nested1" aria-labelledby="ariaid-title34" id="incompatible_changes__incompatible_changes_10">
- <h2 class="title topictitle2" id="ariaid-title33">Incompatible Changes Introduced in Impala 1.0</h2>
+ <h2 class="title topictitle2" id="ariaid-title34">Incompatible Changes Introduced in Impala 1.0</h2>
<div class="body conbody">
http://git-wip-us.apache.org/repos/asf/incubator-impala/blob/ca9005be/docs/build/html/topics/impala_joins.html
----------------------------------------------------------------------
diff --git a/docs/build/html/topics/impala_joins.html b/docs/build/html/topics/impala_joins.html
index 436f9f5..b49dd3a 100644
--- a/docs/build/html/topics/impala_joins.html
+++ b/docs/build/html/topics/impala_joins.html
@@ -25,7 +25,7 @@
are supported in all Impala versions. The <code class="ph codeph">CROSS JOIN</code> operator is available in Impala 1.2.2
and higher. During performance tuning, you can override the reordering of join clauses that Impala does
internally by including the keyword <code class="ph codeph">STRAIGHT_JOIN</code> immediately after the
- <code class="ph codeph">SELECT</code> keyword
+ <code class="ph codeph">SELECT</code> and any <code class="ph codeph">DISTINCT</code> or <code class="ph codeph">ALL</code> keywords.
</p>
<pre class="pre codeblock"><code>SELECT <var class="keyword varname">select_list</var> FROM
http://git-wip-us.apache.org/repos/asf/incubator-impala/blob/ca9005be/docs/build/html/topics/impala_known_issues.html
----------------------------------------------------------------------
diff --git a/docs/build/html/topics/impala_known_issues.html b/docs/build/html/topics/impala_known_issues.html
index f9017d2..3b148ee 100644
--- a/docs/build/html/topics/impala_known_issues.html
+++ b/docs/build/html/topics/impala_known_issues.html
@@ -209,11 +209,37 @@
</div>
- <article class="topic concept nested3" aria-labelledby="ariaid-title11" id="known_issues_performance__IMPALA-1480">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title11" id="known_issues_performance__IMPALA-3316">
+ <h4 class="title topictitle4" id="ariaid-title11">Slow queries for Parquet tables with convert_legacy_hive_parquet_utc_timestamps=true</h4>
+ <div class="body conbody">
+ <p class="p">
+ The configuration setting <code class="ph codeph">convert_legacy_hive_parquet_utc_timestamps=true</code>
+ uses an underlying function that can be a bottleneck on high volume, highly concurrent
+ queries due to the use of a global lock while loading time zone information. This bottleneck
+ can cause slowness when querying Parquet tables, up to 30x for scan-heavy queries. The amount
+ of slowdown depends on factors such as the number of cores and number of threads involved in the query.
+ </p>
+ <div class="note note note_note"><span class="note__title notetitle">Note:</span>
+ <p class="p">
+ The slowdown only occurs when accessing <code class="ph codeph">TIMESTAMP</code> columns within Parquet files that
+ were generated by Hive, and therefore require the on-the-fly timezone conversion processing.
+ </p>
+ </div>
+ <p class="p"><strong class="ph b">Bug:</strong> <a class="xref" href="https://issues.apache.org/jira/browse/IMPALA-3316" target="_blank">IMPALA-3316</a></p>
+ <p class="p"><strong class="ph b">Severity:</strong> High</p>
+ <p class="p"><strong class="ph b">Workaround:</strong> If the <code class="ph codeph">TIMESTAMP</code> values stored in the table represent dates only,
+ with no time portion, consider storing them as strings in <code class="ph codeph">yyyy-MM-dd</code> format.
+ Impala implicitly converts such string values to <code class="ph codeph">TIMESTAMP</code> in calls to date/time
+ functions.
+ </p>
+ </div>
+ </article>
+
+ <article class="topic concept nested3" aria-labelledby="ariaid-title12" id="known_issues_performance__IMPALA-1480">
- <h4 class="title topictitle4" id="ariaid-title11">Slow DDL statements for tables with large number of partitions</h4>
+ <h4 class="title topictitle4" id="ariaid-title12">Slow DDL statements for tables with large number of partitions</h4>
<div class="body conbody">
@@ -235,6 +261,33 @@
</article>
+ <article class="topic concept nested3" aria-labelledby="ariaid-title13" id="known_issues_performance__ki_file_handle_cache">
+ <h4 class="title topictitle4" id="ariaid-title13">Interaction of File Handle Cache with HDFS Appends and Short-Circuit Reads</h4>
+ <div class="body conbody">
+ <p class="p">
+ If a data file used by Impala is being continuously appended or overwritten in place by an
+ HDFS mechanism, such as <span class="keyword cmdname">hdfs dfs -appendToFile</span>, interaction with the
+ file handle caching feature in <span class="keyword">Impala 2.10</span> and higher could cause
+ short-circuit reads to sometimes be disabled on some DataNodes. When a mismatch is detected
+ between the cached file handle and a data block that was rewritten because of an append,
+ short-circuit reads are turned off on the affected host for a 10-minute period.
+ </p>
+ <p class="p">
+ The possibility of encountering such an issue is the reason why the file handle caching
+ feature is currently turned off by default. See <a class="xref" href="impala_scalability.html">Scalability Considerations for Impala</a>
+ for information about this feature and how to enable it.
+ </p>
+ <p class="p"><strong class="ph b">Bug:</strong> <a class="xref" href="https://issues.apache.org/jira/browse/HDFS-12528" target="_blank">HDFS-12528</a></p>
+ <p class="p"><strong class="ph b">Severity:</strong> High</p>
+
+ <p class="p"><strong class="ph b">Workaround:</strong> Verify whether your ETL process is susceptible to this issue before enabling the file handle caching feature.
+ You can set the <span class="keyword cmdname">impalad</span> configuration option <code class="ph codeph">unused_file_handle_timeout_sec</code> to a time period
+ that is shorter than the HDFS setting <code class="ph codeph">dfs.client.read.shortcircuit.streams.cache.expiry.ms</code>. (Keep in mind that
+ the HDFS setting is in milliseconds while the Impala setting is in seconds.)
+ </p>
+ </div>
+ </article>
+
</article>
<article class="topic concept nested2" aria-labelledby="known_issues_usability__ki_usability" id="known_issues_crash__known_issues_usability">
@@ -249,8 +302,8 @@
</div>
- <article class="topic concept nested3" aria-labelledby="ariaid-title13" id="known_issues_usability__IMPALA-4570">
- <h4 class="title topictitle4" id="ariaid-title13">Impala shell tarball is not usable on systems with setuptools versions where '0.7' is a substring of the full version string</h4>
+ <article class="topic concept nested3" aria-labelledby="ariaid-title15" id="known_issues_usability__IMPALA-4570">
+ <h4 class="title topictitle4" id="ariaid-title15">Impala shell tarball is not usable on systems with setuptools versions where '0.7' is a substring of the full version string</h4>
<div class="body conbody">
<p class="p">
For example, this issue could occur on a system using setuptools version 20.7.0.
@@ -264,9 +317,9 @@
</div>
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title14" id="known_issues_usability__IMPALA-3133">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title16" id="known_issues_usability__IMPALA-3133">
- <h4 class="title topictitle4" id="ariaid-title14">Unexpected privileges in show output</h4>
+ <h4 class="title topictitle4" id="ariaid-title16">Unexpected privileges in show output</h4>
<div class="body conbody">
@@ -294,9 +347,9 @@
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title15" id="known_issues_usability__IMPALA-1776">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title17" id="known_issues_usability__IMPALA-1776">
- <h4 class="title topictitle4" id="ariaid-title15">Less than 100% progress on completed simple SELECT queries</h4>
+ <h4 class="title topictitle4" id="ariaid-title17">Less than 100% progress on completed simple SELECT queries</h4>
<div class="body conbody">
@@ -312,9 +365,9 @@
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title16" id="known_issues_usability__concept_lmx_dk5_lx">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title18" id="known_issues_usability__concept_lmx_dk5_lx">
- <h4 class="title topictitle4" id="ariaid-title16">Unexpected column overflow behavior with INT datatypes</h4>
+ <h4 class="title topictitle4" id="ariaid-title18">Unexpected column overflow behavior with INT datatypes</h4>
<div class="body conbody">
@@ -351,11 +404,11 @@
</div>
- <article class="topic concept nested3" aria-labelledby="ariaid-title18" id="known_issues_drivers__IMPALA-1792">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title20" id="known_issues_drivers__IMPALA-1792">
- <h4 class="title topictitle4" id="ariaid-title18">ImpalaODBC: Can not get the value in the SQLGetData(m-x th column) after the SQLBindCol(m th column)</h4>
+ <h4 class="title topictitle4" id="ariaid-title20">ImpalaODBC: Can not get the value in the SQLGetData(m-x th column) after the SQLBindCol(m th column)</h4>
<div class="body conbody">
@@ -392,11 +445,32 @@
</div>
- <article class="topic concept nested3" aria-labelledby="ariaid-title20" id="known_issues_security__renewable_kerberos_tickets">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title22" id="known_issues_security__IMPALA-5638">
+ <h4 class="title topictitle4" id="ariaid-title22">Malicious user can gain unauthorized access to Kudu table data via Impala</h4>
+ <div class="body conbody">
+ <p class="p">
+ A malicious user with <code class="ph codeph">ALTER</code> permissions on an Impala table can access any
+ other Kudu table data by altering the table properties to make it <span class="q">"external"</span>
+ and then changing the underlying table mapping to point to other Kudu tables.
+ This violates and works around the authorization requirement that creating a
+ Kudu external table via Impala requires an <code class="ph codeph">ALL</code> privilege at the server scope.
+ This privilege requirement for <code class="ph codeph">CREATE</code> commands is enforced to precisely avoid
+ this scenario where a malicious user can change the underlying Kudu table
+ mapping. The fix is to enforce the same privilege requirement for <code class="ph codeph">ALTER</code>
+ commands that would make existing non-external Kudu tables external.
+ </p>
+ <p class="p"><strong class="ph b">Bug:</strong> <a class="xref" href="https://issues.apache.org/jira/browse/IMPALA-5638" target="_blank">IMPALA-5638</a></p>
+ <p class="p"><strong class="ph b">Severity:</strong> High</p>
+ <p class="p"><strong class="ph b">Workaround:</strong> A temporary workaround is to revoke <code class="ph codeph">ALTER</code> permissions on Impala tables.</p>
+ <p class="p"><strong class="ph b">Resolution:</strong> Upgrade to an Impala version containing the fix for <a class="xref" href="https://issues.apache.org/jira/browse/IMPALA-5638" target="_blank">IMPALA-5638</a>.</p>
+ </div>
+ </article>
+
+ <article class="topic concept nested3" aria-labelledby="ariaid-title23" id="known_issues_security__renewable_kerberos_tickets">
- <h4 class="title topictitle4" id="ariaid-title20">Kerberos tickets must be renewable</h4>
+ <h4 class="title topictitle4" id="ariaid-title23">Kerberos tickets must be renewable</h4>
<div class="body conbody">
@@ -432,8 +506,8 @@
</div>
- <article class="topic concept nested3" aria-labelledby="ariaid-title22" id="known_issues_resources__IMPALA-5605">
- <h4 class="title topictitle4" id="ariaid-title22">Configuration to prevent crashes caused by thread resource limits</h4>
+ <article class="topic concept nested3" aria-labelledby="ariaid-title25" id="known_issues_resources__IMPALA-5605">
+ <h4 class="title topictitle4" id="ariaid-title25">Configuration to prevent crashes caused by thread resource limits</h4>
<div class="body conbody">
<p class="p">
Impala could encounter a serious error due to resource usage under very high concurrency.
@@ -465,8 +539,8 @@ impala hard nproc 262144
</div>
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title23" id="known_issues_resources__flatbuffers_mem_usage">
- <h4 class="title topictitle4" id="ariaid-title23">Memory usage when compact_catalog_topic flag enabled</h4>
+ <article class="topic concept nested3" aria-labelledby="ariaid-title26" id="known_issues_resources__flatbuffers_mem_usage">
+ <h4 class="title topictitle4" id="ariaid-title26">Memory usage when compact_catalog_topic flag enabled</h4>
<div class="body conbody">
<p class="p">
The efficiency improvement from <a class="xref" href="https://issues.apache.org/jira/browse/IMPALA-4029" target="_blank">IMPALA-4029</a>
@@ -491,8 +565,8 @@ impala hard nproc 262144
</div>
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title24" id="known_issues_resources__IMPALA-2294">
- <h4 class="title topictitle4" id="ariaid-title24">Kerberos initialization errors due to high memory usage</h4>
+ <article class="topic concept nested3" aria-labelledby="ariaid-title27" id="known_issues_resources__IMPALA-2294">
+ <h4 class="title topictitle4" id="ariaid-title27">Kerberos initialization errors due to high memory usage</h4>
<div class="body conbody">
<div class="p">
On a kerberized cluster with high memory utilization, <span class="keyword cmdname">kinit</span> commands executed after
@@ -529,8 +603,8 @@ vm.overcommit_memory=1
</div>
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title25" id="known_issues_resources__drop_table_purge_s3a">
- <h4 class="title topictitle4" id="ariaid-title25">DROP TABLE PURGE on S3A table may not delete externally written files</h4>
+ <article class="topic concept nested3" aria-labelledby="ariaid-title28" id="known_issues_resources__drop_table_purge_s3a">
+ <h4 class="title topictitle4" id="ariaid-title28">DROP TABLE PURGE on S3A table may not delete externally written files</h4>
<div class="body conbody">
<p class="p">
A <code class="ph codeph">DROP TABLE PURGE</code> statement against an S3 table could leave the data files
@@ -543,9 +617,9 @@ vm.overcommit_memory=1
</div>
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title26" id="known_issues_resources__catalogd_heap">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title29" id="known_issues_resources__catalogd_heap">
- <h4 class="title topictitle4" id="ariaid-title26">Impala catalogd heap issues when upgrading to <span class="keyword">Impala 2.5</span></h4>
+ <h4 class="title topictitle4" id="ariaid-title29">Impala catalogd heap issues when upgrading to <span class="keyword">Impala 2.5</span></h4>
<div class="body conbody">
@@ -628,9 +702,9 @@ vm.overcommit_memory=1
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title27" id="known_issues_resources__IMPALA-3509">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title30" id="known_issues_resources__IMPALA-3509">
- <h4 class="title topictitle4" id="ariaid-title27">Breakpad minidumps can be very large when the thread count is high</h4>
+ <h4 class="title topictitle4" id="ariaid-title30">Breakpad minidumps can be very large when the thread count is high</h4>
<div class="body conbody">
@@ -659,9 +733,9 @@ vm.overcommit_memory=1
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title28" id="known_issues_resources__IMPALA-3662">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title31" id="known_issues_resources__IMPALA-3662">
- <h4 class="title topictitle4" id="ariaid-title28">Parquet scanner memory increase after IMPALA-2736</h4>
+ <h4 class="title topictitle4" id="ariaid-title31">Parquet scanner memory increase after IMPALA-2736</h4>
<div class="body conbody">
@@ -725,9 +799,9 @@ vm.overcommit_memory=1
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title29" id="known_issues_resources__IMPALA-691">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title32" id="known_issues_resources__IMPALA-691">
- <h4 class="title topictitle4" id="ariaid-title29">Process mem limit does not account for the JVM's memory usage</h4>
+ <h4 class="title topictitle4" id="ariaid-title32">Process mem limit does not account for the JVM's memory usage</h4>
@@ -751,11 +825,11 @@ vm.overcommit_memory=1
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title30" id="known_issues_resources__IMPALA-2375">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title33" id="known_issues_resources__IMPALA-2375">
- <h4 class="title topictitle4" id="ariaid-title30">Fix issues with the legacy join and agg nodes using --enable_partitioned_hash_join=false and --enable_partitioned_aggregation=false</h4>
+ <h4 class="title topictitle4" id="ariaid-title33">Fix issues with the legacy join and agg nodes using --enable_partitioned_hash_join=false and --enable_partitioned_aggregation=false</h4>
<div class="body conbody">
@@ -789,8 +863,8 @@ vm.overcommit_memory=1
</div>
- <article class="topic concept nested3" aria-labelledby="ariaid-title32" id="known_issues_correctness__IMPALA-4513">
- <h4 class="title topictitle4" id="ariaid-title32">ABS(n) where n is the lowest bound for the int types returns negative values</h4>
+ <article class="topic concept nested3" aria-labelledby="ariaid-title35" id="known_issues_correctness__IMPALA-4513">
+ <h4 class="title topictitle4" id="ariaid-title35">ABS(n) where n is the lowest bound for the int types returns negative values</h4>
<div class="body conbody">
<p class="p">
If the <code class="ph codeph">abs()</code> function evaluates a number that is right at the lower bound for
@@ -806,8 +880,8 @@ vm.overcommit_memory=1
</div>
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title33" id="known_issues_correctness__IMPALA-4266">
- <h4 class="title topictitle4" id="ariaid-title33">Java udf expression returning string in group by can give incorrect results.</h4>
+ <article class="topic concept nested3" aria-labelledby="ariaid-title36" id="known_issues_correctness__IMPALA-4266">
+ <h4 class="title topictitle4" id="ariaid-title36">Java udf expression returning string in group by can give incorrect results.</h4>
<div class="body conbody">
<p class="p">
If the <code class="ph codeph">GROUP BY</code> clause included a call to a Java UDF that returned a string value,
@@ -823,9 +897,9 @@ vm.overcommit_memory=1
</div>
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title34" id="known_issues_correctness__IMPALA-3084">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title37" id="known_issues_correctness__IMPALA-3084">
- <h4 class="title topictitle4" id="ariaid-title34">Incorrect assignment of NULL checking predicate through an outer join of a nested collection.</h4>
+ <h4 class="title topictitle4" id="ariaid-title37">Incorrect assignment of NULL checking predicate through an outer join of a nested collection.</h4>
<div class="body conbody">
@@ -849,9 +923,9 @@ vm.overcommit_memory=1
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title35" id="known_issues_correctness__IMPALA-3094">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title38" id="known_issues_correctness__IMPALA-3094">
- <h4 class="title topictitle4" id="ariaid-title35">Incorrect result due to constant evaluation in query with outer join</h4>
+ <h4 class="title topictitle4" id="ariaid-title38">Incorrect result due to constant evaluation in query with outer join</h4>
<div class="body conbody">
@@ -894,9 +968,9 @@ explain SELECT 1 FROM alltypestiny a1
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title36" id="known_issues_correctness__IMPALA-3126">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title39" id="known_issues_correctness__IMPALA-3126">
- <h4 class="title topictitle4" id="ariaid-title36">Incorrect assignment of an inner join On-clause predicate through an outer join.</h4>
+ <h4 class="title topictitle4" id="ariaid-title39">Incorrect assignment of an inner join On-clause predicate through an outer join.</h4>
<div class="body conbody">
@@ -1072,9 +1146,9 @@ where b.int_col = c.int_col
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title37" id="known_issues_correctness__IMPALA-3006">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title40" id="known_issues_correctness__IMPALA-3006">
- <h4 class="title topictitle4" id="ariaid-title37">Impala may use incorrect bit order with BIT_PACKED encoding</h4>
+ <h4 class="title topictitle4" id="ariaid-title40">Impala may use incorrect bit order with BIT_PACKED encoding</h4>
<div class="body conbody">
@@ -1095,9 +1169,9 @@ where b.int_col = c.int_col
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title38" id="known_issues_correctness__IMPALA-3082">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title41" id="known_issues_correctness__IMPALA-3082">
- <h4 class="title topictitle4" id="ariaid-title38">BST between 1972 and 1995</h4>
+ <h4 class="title topictitle4" id="ariaid-title41">BST between 1972 and 1995</h4>
<div class="body conbody">
@@ -1126,9 +1200,9 @@ select
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title39" id="known_issues_correctness__IMPALA-1170">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title42" id="known_issues_correctness__IMPALA-1170">
- <h4 class="title topictitle4" id="ariaid-title39">parse_url() returns incorrect result if @ character in URL</h4>
+ <h4 class="title topictitle4" id="ariaid-title42">parse_url() returns incorrect result if @ character in URL</h4>
<div class="body conbody">
@@ -1147,9 +1221,9 @@ select
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title40" id="known_issues_correctness__IMPALA-2422">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title43" id="known_issues_correctness__IMPALA-2422">
- <h4 class="title topictitle4" id="ariaid-title40">% escaping does not work correctly when occurs at the end in a LIKE clause</h4>
+ <h4 class="title topictitle4" id="ariaid-title43">% escaping does not work correctly when occurs at the end in a LIKE clause</h4>
<div class="body conbody">
@@ -1166,9 +1240,9 @@ select
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title41" id="known_issues_correctness__IMPALA-397">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title44" id="known_issues_correctness__IMPALA-397">
- <h4 class="title topictitle4" id="ariaid-title41">ORDER BY rand() does not work.</h4>
+ <h4 class="title topictitle4" id="ariaid-title44">ORDER BY rand() does not work.</h4>
<div class="body conbody">
@@ -1185,9 +1259,9 @@ select
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title42" id="known_issues_correctness__IMPALA-2643">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title45" id="known_issues_correctness__IMPALA-2643">
- <h4 class="title topictitle4" id="ariaid-title42">Duplicated column in inline view causes dropping null slots during scan</h4>
+ <h4 class="title topictitle4" id="ariaid-title45">Duplicated column in inline view causes dropping null slots during scan</h4>
<div class="body conbody">
@@ -1210,11 +1284,11 @@ select
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title43" id="known_issues_correctness__IMPALA-1459">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title46" id="known_issues_correctness__IMPALA-1459">
- <h4 class="title topictitle4" id="ariaid-title43">Incorrect assignment of predicates through an outer join in an inline view.</h4>
+ <h4 class="title topictitle4" id="ariaid-title46">Incorrect assignment of predicates through an outer join in an inline view.</h4>
<div class="body conbody">
@@ -1233,9 +1307,9 @@ select
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title44" id="known_issues_correctness__IMPALA-2603">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title47" id="known_issues_correctness__IMPALA-2603">
- <h4 class="title topictitle4" id="ariaid-title44">Crash: impala::Coordinator::ValidateCollectionSlots</h4>
+ <h4 class="title topictitle4" id="ariaid-title47">Crash: impala::Coordinator::ValidateCollectionSlots</h4>
<div class="body conbody">
@@ -1252,9 +1326,9 @@ select
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title45" id="known_issues_correctness__IMPALA-2665">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title48" id="known_issues_correctness__IMPALA-2665">
- <h4 class="title topictitle4" id="ariaid-title45">Incorrect assignment of On-clause predicate inside inline view with an outer join.</h4>
+ <h4 class="title topictitle4" id="ariaid-title48">Incorrect assignment of On-clause predicate inside inline view with an outer join.</h4>
<div class="body conbody">
@@ -1287,9 +1361,9 @@ select
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title46" id="known_issues_correctness__IMPALA-2144">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title49" id="known_issues_correctness__IMPALA-2144">
- <h4 class="title topictitle4" id="ariaid-title46">Wrong assignment of having clause predicate across outer join</h4>
+ <h4 class="title topictitle4" id="ariaid-title49">Wrong assignment of having clause predicate across outer join</h4>
<div class="body conbody">
@@ -1308,9 +1382,9 @@ select
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title47" id="known_issues_correctness__IMPALA-2093">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title50" id="known_issues_correctness__IMPALA-2093">
- <h4 class="title topictitle4" id="ariaid-title47">Wrong plan of NOT IN aggregate subquery when a constant is used in subquery predicate</h4>
+ <h4 class="title topictitle4" id="ariaid-title50">Wrong plan of NOT IN aggregate subquery when a constant is used in subquery predicate</h4>
<div class="body conbody">
@@ -1344,9 +1418,9 @@ select
</div>
- <article class="topic concept nested3" aria-labelledby="ariaid-title49" id="known_issues_metadata__IMPALA-2648">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title52" id="known_issues_metadata__IMPALA-2648">
- <h4 class="title topictitle4" id="ariaid-title49">Catalogd may crash when loading metadata for tables with many partitions, many columns and with incremental stats</h4>
+ <h4 class="title topictitle4" id="ariaid-title52">Catalogd may crash when loading metadata for tables with many partitions, many columns and with incremental stats</h4>
<div class="body conbody">
@@ -1371,11 +1445,11 @@ select
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title50" id="known_issues_metadata__IMPALA-1420">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title53" id="known_issues_metadata__IMPALA-1420">
- <h4 class="title topictitle4" id="ariaid-title50">Can't update stats manually via alter table after upgrading to <span class="keyword">Impala 2.0</span></h4>
+ <h4 class="title topictitle4" id="ariaid-title53">Can't update stats manually via alter table after upgrading to <span class="keyword">Impala 2.0</span></h4>
<div class="body conbody">
@@ -1420,9 +1494,9 @@ select
- <article class="topic concept nested3" aria-labelledby="ariaid-title52" id="known_issues_interop__describe_formatted_avro">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title55" id="known_issues_interop__describe_formatted_avro">
- <h4 class="title topictitle4" id="ariaid-title52">DESCRIBE FORMATTED gives error on Avro table</h4>
+ <h4 class="title topictitle4" id="ariaid-title55">DESCRIBE FORMATTED gives error on Avro table</h4>
<div class="body conbody">
@@ -1454,11 +1528,11 @@ ALTER TABLE table_name SET TBLPROPERTIES('EXTERNAL'='TRUE');
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title53" id="known_issues_interop__IMP-469">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title56" id="known_issues_interop__IMP-469">
- <h4 class="title topictitle4" id="ariaid-title53">Deviation from Hive behavior: Impala does not do implicit casts between string and numeric and boolean types.</h4>
+ <h4 class="title topictitle4" id="ariaid-title56">Deviation from Hive behavior: Impala does not do implicit casts between string and numeric and boolean types.</h4>
<div class="body conbody">
@@ -1474,11 +1548,11 @@ ALTER TABLE table_name SET TBLPROPERTIES('EXTERNAL'='TRUE');
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title54" id="known_issues_interop__IMP-175">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title57" id="known_issues_interop__IMP-175">
- <h4 class="title topictitle4" id="ariaid-title54">Deviation from Hive behavior: Out of range values float/double values are returned as maximum allowed value of type (Hive returns NULL)</h4>
+ <h4 class="title topictitle4" id="ariaid-title57">Deviation from Hive behavior: Out of range values float/double values are returned as maximum allowed value of type (Hive returns NULL)</h4>
<div class="body conbody">
@@ -1495,11 +1569,11 @@ ALTER TABLE table_name SET TBLPROPERTIES('EXTERNAL'='TRUE');
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title55" id="known_issues_interop__flume_writeformat_text">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title58" id="known_issues_interop__flume_writeformat_text">
- <h4 class="title topictitle4" id="ariaid-title55">Configuration needed for Flume to be compatible with Impala</h4>
+ <h4 class="title topictitle4" id="ariaid-title58">Configuration needed for Flume to be compatible with Impala</h4>
<div class="body conbody">
@@ -1518,11 +1592,11 @@ ALTER TABLE table_name SET TBLPROPERTIES('EXTERNAL'='TRUE');
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title56" id="known_issues_interop__IMPALA-635">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title59" id="known_issues_interop__IMPALA-635">
- <h4 class="title topictitle4" id="ariaid-title56">Avro Scanner fails to parse some schemas</h4>
+ <h4 class="title topictitle4" id="ariaid-title59">Avro Scanner fails to parse some schemas</h4>
<div class="body conbody">
@@ -1548,11 +1622,11 @@ ALTER TABLE table_name SET TBLPROPERTIES('EXTERNAL'='TRUE');
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title57" id="known_issues_interop__IMPALA-1024">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title60" id="known_issues_interop__IMPALA-1024">
- <h4 class="title topictitle4" id="ariaid-title57">Impala BE cannot parse Avro schema that contains a trailing semi-colon</h4>
+ <h4 class="title topictitle4" id="ariaid-title60">Impala BE cannot parse Avro schema that contains a trailing semi-colon</h4>
<div class="body conbody">
@@ -1572,11 +1646,11 @@ ALTER TABLE table_name SET TBLPROPERTIES('EXTERNAL'='TRUE');
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title58" id="known_issues_interop__IMPALA-2154">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title61" id="known_issues_interop__IMPALA-2154">
- <h4 class="title topictitle4" id="ariaid-title58">Fix decompressor to allow parsing gzips with multiple streams</h4>
+ <h4 class="title topictitle4" id="ariaid-title61">Fix decompressor to allow parsing gzips with multiple streams</h4>
<div class="body conbody">
@@ -1599,11 +1673,11 @@ ALTER TABLE table_name SET TBLPROPERTIES('EXTERNAL'='TRUE');
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title59" id="known_issues_interop__IMPALA-1578">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title62" id="known_issues_interop__IMPALA-1578">
- <h4 class="title topictitle4" id="ariaid-title59">Impala incorrectly handles text data when the new line character \n\r is split between different HDFS block</h4>
+ <h4 class="title topictitle4" id="ariaid-title62">Impala incorrectly handles text data when the new line character \n\r is split between different HDFS block</h4>
<div class="body conbody">
@@ -1626,11 +1700,11 @@ ALTER TABLE table_name SET TBLPROPERTIES('EXTERNAL'='TRUE');
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title60" id="known_issues_interop__IMPALA-1862">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title63" id="known_issues_interop__IMPALA-1862">
- <h4 class="title topictitle4" id="ariaid-title60">Invalid bool value not reported as a scanner error</h4>
+ <h4 class="title topictitle4" id="ariaid-title63">Invalid bool value not reported as a scanner error</h4>
<div class="body conbody">
@@ -1648,11 +1722,11 @@ ALTER TABLE table_name SET TBLPROPERTIES('EXTERNAL'='TRUE');
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title61" id="known_issues_interop__IMPALA-1652">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title64" id="known_issues_interop__IMPALA-1652">
- <h4 class="title topictitle4" id="ariaid-title61">Incorrect results with basic predicate on CHAR typed column.</h4>
+ <h4 class="title topictitle4" id="ariaid-title64">Incorrect results with basic predicate on CHAR typed column.</h4>
<div class="body conbody">
@@ -1676,9 +1750,9 @@ ALTER TABLE table_name SET TBLPROPERTIES('EXTERNAL'='TRUE');
</article>
- <article class="topic concept nested2" aria-labelledby="ariaid-title62" id="known_issues_crash__known_issues_limitations">
+ <article class="topic concept nested2" aria-labelledby="ariaid-title65" id="known_issues_crash__known_issues_limitations">
- <h3 class="title topictitle3" id="ariaid-title62">Impala Known Issues: Limitations</h3>
+ <h3 class="title topictitle3" id="ariaid-title65">Impala Known Issues: Limitations</h3>
<div class="body conbody">
@@ -1689,8 +1763,8 @@ ALTER TABLE table_name SET TBLPROPERTIES('EXTERNAL'='TRUE');
</div>
- <article class="topic concept nested3" aria-labelledby="ariaid-title63" id="known_issues_limitations__IMPALA-4551">
- <h4 class="title topictitle4" id="ariaid-title63">Set limits on size of expression trees</h4>
+ <article class="topic concept nested3" aria-labelledby="ariaid-title66" id="known_issues_limitations__IMPALA-4551">
+ <h4 class="title topictitle4" id="ariaid-title66">Set limits on size of expression trees</h4>
<div class="body conbody">
<p class="p">
Very deeply nested expressions within queries can exceed internal Impala limits,
@@ -1704,11 +1778,11 @@ ALTER TABLE table_name SET TBLPROPERTIES('EXTERNAL'='TRUE');
</div>
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title64" id="known_issues_limitations__IMPALA-77">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title67" id="known_issues_limitations__IMPALA-77">
- <h4 class="title topictitle4" id="ariaid-title64">Impala does not support running on clusters with federated namespaces</h4>
+ <h4 class="title topictitle4" id="ariaid-title67">Impala does not support running on clusters with federated namespaces</h4>
<div class="body conbody">
@@ -1735,9 +1809,9 @@ ALTER TABLE table_name SET TBLPROPERTIES('EXTERNAL'='TRUE');
</article>
- <article class="topic concept nested2" aria-labelledby="ariaid-title65" id="known_issues_crash__known_issues_misc">
+ <article class="topic concept nested2" aria-labelledby="ariaid-title68" id="known_issues_crash__known_issues_misc">
- <h3 class="title topictitle3" id="ariaid-title65">Impala Known Issues: Miscellaneous / Older Issues</h3>
+ <h3 class="title topictitle3" id="ariaid-title68">Impala Known Issues: Miscellaneous / Older Issues</h3>
<div class="body conbody">
@@ -1747,11 +1821,11 @@ ALTER TABLE table_name SET TBLPROPERTIES('EXTERNAL'='TRUE');
</div>
- <article class="topic concept nested3" aria-labelledby="ariaid-title66" id="known_issues_misc__IMPALA-2005">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title69" id="known_issues_misc__IMPALA-2005">
- <h4 class="title topictitle4" id="ariaid-title66">A failed CTAS does not drop the table if the insert fails.</h4>
+ <h4 class="title topictitle4" id="ariaid-title69">A failed CTAS does not drop the table if the insert fails.</h4>
<div class="body conbody">
@@ -1772,11 +1846,11 @@ ALTER TABLE table_name SET TBLPROPERTIES('EXTERNAL'='TRUE');
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title67" id="known_issues_misc__IMPALA-1821">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title70" id="known_issues_misc__IMPALA-1821">
- <h4 class="title topictitle4" id="ariaid-title67">Casting scenarios with invalid/inconsistent results</h4>
+ <h4 class="title topictitle4" id="ariaid-title70">Casting scenarios with invalid/inconsistent results</h4>
<div class="body conbody">
@@ -1796,11 +1870,11 @@ ALTER TABLE table_name SET TBLPROPERTIES('EXTERNAL'='TRUE');
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title68" id="known_issues_misc__IMPALA-1619">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title71" id="known_issues_misc__IMPALA-1619">
- <h4 class="title topictitle4" id="ariaid-title68">Support individual memory allocations larger than 1 GB</h4>
+ <h4 class="title topictitle4" id="ariaid-title71">Support individual memory allocations larger than 1 GB</h4>
<div class="body conbody">
@@ -1820,11 +1894,11 @@ ALTER TABLE table_name SET TBLPROPERTIES('EXTERNAL'='TRUE');
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title69" id="known_issues_misc__IMPALA-941">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title72" id="known_issues_misc__IMPALA-941">
- <h4 class="title topictitle4" id="ariaid-title69">Impala Parser issue when using fully qualified table names that start with a number.</h4>
+ <h4 class="title topictitle4" id="ariaid-title72">Impala Parser issue when using fully qualified table names that start with a number.</h4>
<div class="body conbody">
@@ -1845,11 +1919,11 @@ ALTER TABLE table_name SET TBLPROPERTIES('EXTERNAL'='TRUE');
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title70" id="known_issues_misc__IMPALA-532">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title73" id="known_issues_misc__IMPALA-532">
- <h4 class="title topictitle4" id="ariaid-title70">Impala should tolerate bad locale settings</h4>
+ <h4 class="title topictitle4" id="ariaid-title73">Impala should tolerate bad locale settings</h4>
<div class="body conbody">
@@ -1874,11 +1948,11 @@ ALTER TABLE table_name SET TBLPROPERTIES('EXTERNAL'='TRUE');
</article>
- <article class="topic concept nested3" aria-labelledby="ariaid-title71" id="known_issues_misc__IMP-1203">
+ <article class="topic concept nested3" aria-labelledby="ariaid-title74" id="known_issues_misc__IMP-1203">
- <h4 class="title topictitle4" id="ariaid-title71">Log Level 3 Not Recommended for Impala</h4>
+ <h4 class="title topictitle4" id="ariaid-title74">Log Level 3 Not Recommended for Impala</h4>
<div class="body conbody">
http://git-wip-us.apache.org/repos/asf/incubator-impala/blob/ca9005be/docs/build/html/topics/impala_kudu.html
----------------------------------------------------------------------
diff --git a/docs/build/html/topics/impala_kudu.html b/docs/build/html/topics/impala_kudu.html
index 1ede7b6..d610595 100644
--- a/docs/build/html/topics/impala_kudu.html
+++ b/docs/build/html/topics/impala_kudu.html
@@ -1389,6 +1389,14 @@ kudu.table_name | impala::some_database.table_name_demo
the predicate pushdown for a specific query against a Kudu table.
</p>
+ <p class="p">
+ The <code class="ph codeph">TABLESAMPLE</code> clause of the <code class="ph codeph">SELECT</code>
+ statement does not apply to a table reference derived from a view, a subquery,
+ or anything other than a real base table. This clause only works for tables
+ backed by HDFS or HDFS-like data files, therefore it does not apply to Kudu or
+ HBase tables.
+ </p>
+
http://git-wip-us.apache.org/repos/asf/incubator-impala/blob/ca9005be/docs/build/html/topics/impala_logging.html
----------------------------------------------------------------------
diff --git a/docs/build/html/topics/impala_logging.html b/docs/build/html/topics/impala_logging.html
index 1882468..995c817 100644
--- a/docs/build/html/topics/impala_logging.html
+++ b/docs/build/html/topics/impala_logging.html
@@ -341,8 +341,7 @@ I0107 08:42:12.292706 14876 logging.cc:76] Flags (see also /varz are on debug we
<p class="p">
For more information on how to configure GLOG, including how to set variable logging levels for different
system components, see
- <a class="xref" href="http://google-glog.googlecode.com/svn/trunk/doc/glog.html" target="_blank">How
- To Use Google Logging Library (glog)</a>.
+ <a class="xref" href="https://github.com/google/glog" target="_blank">documentation for the glog project on github</a>.
</p>
<section class="section" id="log_levels__loglevels_details"><h3 class="title sectiontitle">Understanding What is Logged at Different Logging Levels</h3>
http://git-wip-us.apache.org/repos/asf/incubator-impala/blob/ca9005be/docs/build/html/topics/impala_map.html
----------------------------------------------------------------------
diff --git a/docs/build/html/topics/impala_map.html b/docs/build/html/topics/impala_map.html
index 96cd2e8..17a1c25 100644
--- a/docs/build/html/topics/impala_map.html
+++ b/docs/build/html/topics/impala_map.html
@@ -102,7 +102,7 @@ type ::= <var class="keyword varname">primitive_type</var> | <var class="keyword
</p>
</li>
<li class="li">
- <p class="p" id="map__d6e3003">
+ <p class="p" id="map__d6e3156">
The maximum length of the column definition for any complex type, including declarations for any nested types,
is 4000 characters.
</p>
http://git-wip-us.apache.org/repos/asf/incubator-impala/blob/ca9005be/docs/build/html/topics/impala_math_functions.html
----------------------------------------------------------------------
diff --git a/docs/build/html/topics/impala_math_functions.html b/docs/build/html/topics/impala_math_functions.html
index 431e6c3..ce10a98 100644
--- a/docs/build/html/topics/impala_math_functions.html
+++ b/docs/build/html/topics/impala_math_functions.html
@@ -1413,66 +1413,209 @@ select x, unix_timestamp(now()), rand(unix_timestamp(now()))
<dt class="dt dlterm" id="math_functions__truncate">
<code class="ph codeph">truncate(double_or_decimal a[, digits_to_leave])</code>,
- <span class="ph" id="math_functions__dtrunc"><code class="ph codeph">dtrunc(double_or_decimal a[, digits_to_leave])</code></span>
+ <span class="ph" id="math_functions__dtrunc"><code class="ph codeph">dtrunc(double_or_decimal a[, digits_to_leave])</code></span>,
+ <span class="ph" id="math_functions__trunc_number"><code class="ph codeph">trunc(double_or_decimal a[, digits_to_leave])</code></span>
</dt>
<dd class="dd">
+
<strong class="ph b">Purpose:</strong> Removes some or all fractional digits from a numeric value.
- With no argument, removes all fractional digits, leaving an integer value.
- The optional argument specifies the number of fractional digits to include
- in the return value, and only applies with the argument type is <code class="ph codeph">DECIMAL</code>.
- <code class="ph codeph">truncate()</code> and <code class="ph codeph">dtrunc()</code> are aliases for the same function.
+ <p class="p">
+ <strong class="ph b">Arguments:</strong>
+ With a single floating-point argument, removes all fractional digits, leaving an
+ integer value. The optional second argument specifies the number of fractional digits
+ to include in the return value, and only applies when the argument type is
+ <code class="ph codeph">DECIMAL</code>. A second argument of 0 truncates to a whole integer value.
+ A second argument of negative N sets N digits to 0 on the left side of the decimal
+ </p>
+ <p class="p">
+ <strong class="ph b">Scale argument:</strong> The scale argument applies only when truncating
+ <code class="ph codeph">DECIMAL</code> values. It is an integer specifying how many
+ significant digits to leave to the right of the decimal point.
+ A scale argument of 0 truncates to a whole integer value. A scale
+ argument of negative N sets N digits to 0 on the left side of the decimal
+ point.
+ </p>
+ <p class="p">
+ <code class="ph codeph">truncate()</code>, <code class="ph codeph">dtrunc()</code>,
+ <span class="ph">and <code class="ph codeph">trunc()</code></span> are aliases for the
+ same function.
+ </p>
<p class="p">
<strong class="ph b">Return type:</strong> <code class="ph codeph">decimal</code> for <code class="ph codeph">DECIMAL</code> arguments;
<code class="ph codeph">bigint</code> for <code class="ph codeph">DOUBLE</code> arguments
</p>
<p class="p">
+ <strong class="ph b">Added in:</strong> The <code class="ph codeph">trunc()</code> alias was added in
+ <span class="keyword">Impala 2.10</span>.
+ </p>
+ <p class="p">
+ <strong class="ph b">Usage notes:</strong>
+ </p>
+ <p class="p">
+ You can also pass a <code class="ph codeph">DOUBLE</code> argument, or <code class="ph codeph">DECIMAL</code>
+ argument with optional scale, to the <code class="ph codeph">dtrunc()</code> or
+ <code class="ph codeph">truncate</code> functions. Using the <code class="ph codeph">trunc()</code>
+ function for numeric values is common with other industry-standard database
+ systems, so you might find such <code class="ph codeph">trunc()</code> calls in code that you
+ are porting to Impala.
+ </p>
+ <p class="p">
+ The <code class="ph codeph">trunc()</code> function also has a signature that applies to
+ <code class="ph codeph">TIMESTAMP</code> values. See <a class="xref" href="impala_datetime_functions.html">Impala Date and Time Functions</a>
+ for details.
+ </p>
+ <p class="p">
<strong class="ph b">Examples:</strong>
</p>
-<pre class="pre codeblock"><code>select truncate(3.45)
+ <p class="p">
+ The following examples demonstrate the <code class="ph codeph">truncate()</code>
+ and <code class="ph codeph">dtrunc()</code> signatures for this function:
+ </p>
+<pre class="pre codeblock"><code>select truncate(3.45);
+----------------+
| truncate(3.45) |
+----------------+
| 3 |
+----------------+
-select truncate(-3.45)
+select truncate(-3.45);
+-----------------+
| truncate(-3.45) |
+-----------------+
| -3 |
+-----------------+
-select truncate(3.456,1)
+select truncate(3.456,1);
+--------------------+
| truncate(3.456, 1) |
+--------------------+
| 3.4 |
+--------------------+
-select dtrunc(3.456,1)
+select dtrunc(3.456,1);
+------------------+
| dtrunc(3.456, 1) |
+------------------+
| 3.4 |
+------------------+
-select truncate(3.456,2)
+select truncate(3.456,2);
+--------------------+
| truncate(3.456, 2) |
+--------------------+
| 3.45 |
+--------------------+
-select truncate(3.456,7)
+select truncate(3.456,7);
+--------------------+
| truncate(3.456, 7) |
+--------------------+
| 3.4560000 |
+--------------------+
</code></pre>
+ <p class="p">
+ The following examples demonstrate using <code class="ph codeph">trunc()</code> with
+ <code class="ph codeph">DECIMAL</code> or <code class="ph codeph">DOUBLE</code> values, and with
+ an optional scale argument for <code class="ph codeph">DECIMAL</code> values.
+ (The behavior is the same for the <code class="ph codeph">truncate()</code> and
+ <code class="ph codeph">dtrunc()</code> aliases also.)
+ </p>
+<pre class="pre codeblock"><code>
+create table t1 (d decimal(20,7));
+
+-- By default, no digits to the right of the decimal point.
+insert into t1 values (1.1), (2.22), (3.333), (4.4444), (5.55555);
+select trunc(d) from t1 order by d;
++----------+
+| trunc(d) |
++----------+
+| 1 |
+| 2 |
+| 3 |
+| 4 |
+| 5 |
++----------+
+
+-- 1 digit to the right of the decimal point.
+select trunc(d,1) from t1 order by d;
++-------------+
+| trunc(d, 1) |
++-------------+
+| 1.1 |
+| 2.2 |
+| 3.3 |
+| 4.4 |
+| 5.5 |
++-------------+
+
+-- 2 digits to the right of the decimal point,
+-- including trailing zeroes if needed.
+select trunc(d,2) from t1 order by d;
++-------------+
+| trunc(d, 2) |
++-------------+
+| 1.10 |
+| 2.22 |
+| 3.33 |
+| 4.44 |
+| 5.55 |
++-------------+
+
+insert into t1 values (9999.9999), (8888.8888);
+
+-- Negative scale truncates digits to the left
+-- of the decimal point.
+select trunc(d,-2) from t1 where d > 100 order by d;
++--------------+
+| trunc(d, -2) |
++--------------+
+| 8800 |
+| 9900 |
++--------------+
+
+-- The scale of the result is adjusted to match the
+-- scale argument.
+select trunc(d,2),
+ precision(trunc(d,2)) as p,
+ scale(trunc(d,2)) as s
+from t1 order by d;
++-------------+----+---+
+| trunc(d, 2) | p | s |
++-------------+----+---+
+| 1.10 | 15 | 2 |
+| 2.22 | 15 | 2 |
+| 3.33 | 15 | 2 |
+| 4.44 | 15 | 2 |
+| 5.55 | 15 | 2 |
+| 8888.88 | 15 | 2 |
+| 9999.99 | 15 | 2 |
++-------------+----+---+
+</code></pre>
+
+<pre class="pre codeblock"><code>
+create table dbl (d double);
+
+insert into dbl values
+ (1.1), (2.22), (3.333), (4.4444), (5.55555),
+ (8888.8888), (9999.9999);
+
+-- With double values, there is no optional scale argument.
+select trunc(d) from dbl order by d;
++----------+
+| trunc(d) |
++----------+
+| 1 |
+| 2 |
+| 3 |
+| 4 |
+| 5 |
+| 8888 |
+| 9999 |
++----------+
+</code></pre>
</dd>
http://git-wip-us.apache.org/repos/asf/incubator-impala/blob/ca9005be/docs/build/html/topics/impala_max_row_size.html
----------------------------------------------------------------------
diff --git a/docs/build/html/topics/impala_max_row_size.html b/docs/build/html/topics/impala_max_row_size.html
new file mode 100644
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+<html lang="en"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta charset="UTF-8"><meta name="copyright" content="(C) Copyright 2017"><meta name="DC.rights.owner" content="(C) Copyright 2017"><meta name="DC.Type" content="concept"><meta name="DC.Relation" scheme="URI" content="../topics/impala_query_options.html"><meta name="prodname" content="Impala"><meta name="prodname" content="Impala"><meta name="version" content="Impala 2.8.x"><meta name="version" content="Impala 2.8.x"><meta name="DC.Format" content="XHTML"><meta name="DC.Identifier" content="max_row_size"><link rel="stylesheet" type="text/css" href="../commonltr.css"><title>MAX_ROW_SIZE Query Option</title></head><body id="max_row_size"><main role="main"><article role="article" aria-labelledby="ariaid-title1">
+
+ <h1 class="title topictitle1" id="ariaid-title1">MAX_ROW_SIZE Query Option</h1>
+
+
+
+ <div class="body conbody">
+
+ <p class="p">
+
+ Ensures that Impala can process rows of at least the specified size. (Larger
+ rows might be successfully processed, but that is not guaranteed.) Applies when
+ constructing intermediate or final rows in the result set. This setting prevents
+ out-of-control memory use when accessing columns containing huge strings.
+ </p>
+
+
+
+ <p class="p">
+ <strong class="ph b">Type:</strong> integer
+ </p>
+
+ <p class="p">
+ <strong class="ph b">Default:</strong>
+ </p>
+ <p class="p">
+ <code class="ph codeph">524288</code> (512 KB)
+ </p>
+
+ <p class="p">
+ <strong class="ph b">Units:</strong> A numeric argument represents a size in bytes; you can also use a suffix of <code class="ph codeph">m</code>
+ or <code class="ph codeph">mb</code> for megabytes, or <code class="ph codeph">g</code> or <code class="ph codeph">gb</code> for gigabytes. If you
+ specify a value with unrecognized formats, subsequent queries fail with an error.
+ </p>
+
+ <p class="p">
+ <strong class="ph b">Added in:</strong> <span class="keyword">Impala 2.10.0</span>
+ </p>
+
+ <p class="p">
+ <strong class="ph b">Usage notes:</strong>
+ </p>
+ <p class="p">
+ If a query fails because it involves rows with long strings and/or
+ many columns, causing the total row size to exceed <code class="ph codeph">MAX_ROW_SIZE</code>
+ bytes, increase the <code class="ph codeph">MAX_ROW_SIZE</code> setting to accommodate
+ the total bytes stored in the largest row. Examine the error messages for any
+ failed queries to see the size of the row that caused the problem.
+ </p>
+ <p class="p">
+ Impala attempts to handle rows that exceed the <code class="ph codeph">MAX_ROW_SIZE</code>
+ value where practical, so in many cases, queries succeed despite having rows
+ that are larger than this setting.
+ </p>
+ <p class="p">
+ Specifying a value that is substantially higher than actually needed can cause
+ Impala to reserve more memory than is necessary to execute the query.
+ </p>
+ <p class="p">
+ In a Hadoop cluster with highly concurrent workloads and queries that process
+ high volumes of data, traditional SQL tuning advice about minimizing wasted memory
+ is worth remembering. For example, if a table has <code class="ph codeph">STRING</code> columns
+ where a single value might be multiple megabytes, make sure that the
+ <code class="ph codeph">SELECT</code> lists in queries only refer to columns that are actually
+ needed in the result set, instead of using the <code class="ph codeph">SELECT *</code> shorthand.
+ </p>
+
+ <p class="p">
+ <strong class="ph b">Examples:</strong>
+ </p>
+
+ <p class="p">
+ The following examples show the kinds of situations where it is necessary to
+ adjust the <code class="ph codeph">MAX_ROW_SIZE</code> setting. First, we create a table
+ containing some very long values in <code class="ph codeph">STRING</code> columns:
+ </p>
+
+<pre class="pre codeblock"><code>
+create table big_strings (s1 string, s2 string, s3 string) stored as parquet;
+
+-- Turn off compression to more easily reason about data volume by doing SHOW TABLE STATS.
+-- Does not actually affect query success or failure, because MAX_ROW_SIZE applies when
+-- column values are materialized in memory.
+set compression_codec=none;
+set;
+...
+ MAX_ROW_SIZE: [524288]
+...
+
+-- A very small row.
+insert into big_strings values ('one', 'two', 'three');
+-- A row right around the default MAX_ROW_SIZE limit: a 500 KiB string and a 30 KiB string.
+insert into big_strings values (repeat('12345',100000), 'short', repeat('123',10000));
+-- A row that is too big if the query has to materialize both S1 and S3.
+insert into big_strings values (repeat('12345',100000), 'short', repeat('12345',100000));
+
+</code></pre>
+
+ <p class="p">
+ With the default <code class="ph codeph">MAX_ROW_SIZE</code> setting, different queries succeed
+ or fail based on which column values have to be materialized during query processing:
+ </p>
+
+<pre class="pre codeblock"><code>
+-- All the S1 values can be materialized within the 512 KB MAX_ROW_SIZE buffer.
+select count(distinct s1) from big_strings;
++--------------------+
+| count(distinct s1) |
++--------------------+
+| 2 |
++--------------------+
+
+-- A row where even the S1 value is too large to materialize within MAX_ROW_SIZE.
+insert into big_strings values (repeat('12345',1000000), 'short', repeat('12345',1000000));
+
+-- The 5 MiB string is too large to materialize. The message explains the size of the result
+-- set row the query is attempting to materialize.
+select count(distinct(s1)) from big_strings;
+WARNINGS: Row of size 4.77 MB could not be materialized in plan node with id 1.
+ Increase the max_row_size query option (currently 512.00 KB) to process larger rows.
+
+-- If more columns are involved, the result set row being materialized is bigger.
+select count(distinct s1, s2, s3) from big_strings;
+WARNINGS: Row of size 9.54 MB could not be materialized in plan node with id 1.
+ Increase the max_row_size query option (currently 512.00 KB) to process larger rows.
+
+-- Column S2, containing only short strings, can still be examined.
+select count(distinct(s2)) from big_strings;
++----------------------+
+| count(distinct (s2)) |
++----------------------+
+| 2 |
++----------------------+
+
+-- Queries that do not materialize the big column values are OK.
+select count(*) from big_strings;
++----------+
+| count(*) |
++----------+
+| 4 |
++----------+
+
+</code></pre>
+
+ <p class="p">
+ The following examples show how adjusting <code class="ph codeph">MAX_ROW_SIZE</code> upward
+ allows queries involving the long string columns to succeed:
+ </p>
+
+<pre class="pre codeblock"><code>
+-- Boosting MAX_ROW_SIZE moderately allows all S1 values to be materialized.
+set max_row_size=7mb;
+
+select count(distinct s1) from big_strings;
++--------------------+
+| count(distinct s1) |
++--------------------+
+| 3 |
++--------------------+
+
+-- But the combination of S1 + S3 strings is still too large.
+select count(distinct s1, s2, s3) from big_strings;
+WARNINGS: Row of size 9.54 MB could not be materialized in plan node with id 1. Increase the max_row_size query option (currently 7.00 MB) to process larger rows.
+
+-- Boosting MAX_ROW_SIZE to larger than the largest row in the table allows
+-- all queries to complete successfully.
+set max_row_size=12mb;
+
+select count(distinct s1, s2, s3) from big_strings;
++----------------------------+
+| count(distinct s1, s2, s3) |
++----------------------------+
+| 4 |
++----------------------------+
+
+</code></pre>
+
+ <p class="p">
+ The following examples show how to reason about appropriate values for
+ <code class="ph codeph">MAX_ROW_SIZE</code>, based on the characteristics of the
+ columns containing the long values:
+ </p>
+
+<pre class="pre codeblock"><code>
+-- With a large MAX_ROW_SIZE in place, we can examine the columns to
+-- understand the practical lower limit for MAX_ROW_SIZE based on the
+-- table structure and column values.
+select max(length(s1) + length(s2) + length(s3)) / 1e6 as megabytes from big_strings;
++-----------+
+| megabytes |
++-----------+
+| 10.000005 |
++-----------+
+
+-- We can also examine the 'Max Size' for each column after computing stats.
+compute stats big_strings;
+show column stats big_strings;
++--------+--------+------------------+--------+----------+-----------+
+| Column | Type | #Distinct Values | #Nulls | Max Size | Avg Size |
++--------+--------+------------------+--------+----------+-----------+
+| s1 | STRING | 2 | -1 | 5000000 | 2500002.5 |
+| s2 | STRING | 2 | -1 | 10 | 7.5 |
+| s3 | STRING | 2 | -1 | 5000000 | 2500005 |
++--------+--------+------------------+--------+----------+-----------+
+
+</code></pre>
+
+ <p class="p">
+ <strong class="ph b">Related information:</strong>
+ </p>
+ <p class="p">
+ <a class="xref" href="impala_buffer_pool_limit.html">BUFFER_POOL_LIMIT Query Option</a>,
+ <a class="xref" href="impala_default_spillable_buffer_size.html">DEFAULT_SPILLABLE_BUFFER_SIZE Query Option</a>,
+ <a class="xref" href="impala_min_spillable_buffer_size.html">MIN_SPILLABLE_BUFFER_SIZE Query Option</a>,
+ <a class="xref" href="impala_scalability.html">Scalability Considerations for Impala</a>
+ </p>
+
+ </div>
+<nav role="navigation" class="related-links"><div class="familylinks"><div class="parentlink"><strong>Parent topic:</strong> <a class="link" href="../topics/impala_query_options.html">Query Options for the SET Statement</a></div></div></nav></article></main></body></html>
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