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impala/docs/topics/impala_bit_functions.xml
Alex Rodoni e8ee827a6d [DOCS] Built-in Functions doc format Changes 
- The function titles were changed to upper case.
- The function titles no longer use <codeph>. <codeph> font appears
smaller than the <p> font.
- Return type were changed to upper case data types.
- Minor typos were fixed, such as extra commas and periods in titles.
- The indexterm dita elememts were removed. Indexterm was incomplete
and WIP. No plan to go ahead and implement it, so removed.

Change-Id: I797532463da8d29fe5bc7543cfdfb5b2b82db197
Reviewed-on: http://gerrit.cloudera.org:8080/11619
Tested-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>
Reviewed-by: Michael Brown <mikeb@cloudera.com>
2018-10-10 18:18:09 +00:00

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<?xml version="1.0" encoding="UTF-8"?>
<!--
Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements. See the NOTICE file
distributed with this work for additional information
regarding copyright ownership. The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied. See the License for the
specific language governing permissions and limitations
under the License.
-->
<!DOCTYPE concept PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">
<concept id="bit_functions" rev="2.3.0">
<title>Impala Bit Functions</title>
<titlealts audience="PDF">
<navtitle>Bit Functions</navtitle>
</titlealts>
<prolog>
<metadata>
<data name="Category" value="Impala"/>
<data name="Category" value="Impala Functions"/>
<data name="Category" value="SQL"/>
<data name="Category" value="Data Analysts"/>
<data name="Category" value="Developers"/>
<data name="Category" value="Querying"/>
</metadata>
</prolog>
<conbody>
<p rev="2.3.0">
Bit manipulation functions perform bitwise operations involved in scientific processing or
computer science algorithms. For example, these functions include setting, clearing, or
testing bits within an integer value, or changing the positions of bits with or without
wraparound.
</p>
<p>
If a function takes two integer arguments that are required to be of the same type, the
smaller argument is promoted to the type of the larger one if required. For example,
<codeph>BITAND(1,4096)</codeph> treats both arguments as <codeph>SMALLINT</codeph>,
because 1 can be represented as a <codeph>TINYINT</codeph> but 4096 requires a
<codeph>SMALLINT</codeph>.
</p>
<p>
Remember that all Impala integer values are signed. Therefore, when dealing with binary
values where the most significant bit is 1, the specified or returned values might be
negative when represented in base 10.
</p>
<p>
Whenever any argument is <codeph>NULL</codeph>, either the input value, bit position, or
number of shift or rotate positions, the return value from any of these functions is also
<codeph>NULL</codeph>
</p>
<p conref="../shared/impala_common.xml#common/related_info"/>
<p>
The bit functions operate on all the integral data types:
<xref href="impala_int.xml#int"/>, <xref href="impala_bigint.xml#bigint"/>,
<xref href="impala_smallint.xml#smallint"/>, and
<xref href="impala_tinyint.xml#tinyint"/>.
</p>
<p>
<b>Function reference:</b>
</p>
<p>
Impala supports the following bit functions:
</p>
<ul>
<li>
<xref href="#bit_functions/bitand">BITAND</xref>
</li>
<li>
<xref href="#bit_functions/bitnot">BITNOT</xref>
</li>
<li>
<xref href="#bit_functions/bitor">BITOR</xref>
</li>
<li>
<xref href="#bit_functions/bitxor">BITXOR</xref>
</li>
<li>
<xref href="#bit_functions/countset">COUNTSET</xref>
</li>
<li>
<xref href="#bit_functions/getbit">GETBIT</xref>
</li>
<li>
<xref href="#bit_functions/rotateleft">ROTATELEFT</xref>
</li>
<li>
<xref href="#bit_functions/rotateright">ROTATERIGHT</xref>
</li>
<li>
<xref href="#bit_functions/setbit">SETBIT</xref>
</li>
<li>
<xref href="#bit_functions/shiftleft">SHIFTLEFT</xref>
</li>
<li>
<xref href="#bit_functions/shiftright">SHIFTRIGHT</xref>
</li>
</ul>
<dl>
<dlentry id="bitand">
<dt>
BITAND(integer_type a, same_type b)
</dt>
<dd>
<b>Purpose:</b> Returns an integer value representing the bits that are set to 1 in
both of the arguments. If the arguments are of different sizes, the smaller is
promoted to the type of the larger.
<p>
<b>Usage notes:</b> The <codeph>BITAND()</codeph> function is equivalent to the
<codeph>&amp;</codeph> binary operator.
</p>
<p conref="../shared/impala_common.xml#common/return_type_same"/>
<p conref="../shared/impala_common.xml#common/added_in_230"/>
<p conref="../shared/impala_common.xml#common/example_blurb"/>
<p>
The following examples show the results of ANDing integer values. 255 contains all 1
bits in its lowermost 7 bits. 32767 contains all 1 bits in its lowermost 15 bits.
<!--
Negative numbers have a 1 in the sign bit and the value is the
<xref href="https://en.wikipedia.org/wiki/Two%27s_complement" scope="external" format="html">two's complement</xref>
of the positive equivalent.
-->
You can use the <codeph>BIN()</codeph> function to check the binary representation
of any integer value, although the result is always represented as a 64-bit value.
If necessary, the smaller argument is promoted to the type of the larger one.
</p>
<codeblock>select bitand(255, 32767); /* 0000000011111111 &amp; 0111111111111111 */
+--------------------+
| bitand(255, 32767) |
+--------------------+
| 255 |
+--------------------+
select bitand(32767, 1); /* 0111111111111111 &amp; 0000000000000001 */
+------------------+
| bitand(32767, 1) |
+------------------+
| 1 |
+------------------+
select bitand(32, 16); /* 00010000 &amp; 00001000 */
+----------------+
| bitand(32, 16) |
+----------------+
| 0 |
+----------------+
select bitand(12,5); /* 00001100 &amp; 00000101 */
+---------------+
| bitand(12, 5) |
+---------------+
| 4 |
+---------------+
select bitand(-1,15); /* 11111111 &amp; 00001111 */
+----------------+
| bitand(-1, 15) |
+----------------+
| 15 |
+----------------+
</codeblock>
</dd>
</dlentry>
<dlentry id="bitnot">
<dt>
BITNOT(integer_type a)
</dt>
<dd>
<b>Purpose:</b> Inverts all the bits of the input argument.
<p>
<b>Usage notes:</b> The <codeph>BITNOT()</codeph> function is equivalent to the
<codeph>~</codeph> unary operator.
</p>
<p conref="../shared/impala_common.xml#common/return_type_same"/>
<p conref="../shared/impala_common.xml#common/added_in_230"/>
<p conref="../shared/impala_common.xml#common/example_blurb"/>
<p>
These examples illustrate what happens when you flip all the bits of an integer
value. The sign always changes. The decimal representation is one different between
the positive and negative values.
<!--
because negative values are represented as the
<xref href="https://en.wikipedia.org/wiki/Two%27s_complement" scope="external" format="html">two's complement</xref>
of the corresponding positive value.
-->
</p>
<codeblock>select bitnot(127); /* 01111111 -> 10000000 */
+-------------+
| bitnot(127) |
+-------------+
| -128 |
+-------------+
select bitnot(16); /* 00010000 -> 11101111 */
+------------+
| bitnot(16) |
+------------+
| -17 |
+------------+
select bitnot(0); /* 00000000 -> 11111111 */
+-----------+
| bitnot(0) |
+-----------+
| -1 |
+-----------+
select bitnot(-128); /* 10000000 -> 01111111 */
+--------------+
| bitnot(-128) |
+--------------+
| 127 |
+--------------+
</codeblock>
</dd>
</dlentry>
<dlentry id="bitor">
<dt>
BITOR(integer_type a, same_type b)
</dt>
<dd>
<b>Purpose:</b> Returns an integer value representing the bits that are set to 1 in
either of the arguments. If the arguments are of different sizes, the smaller is
promoted to the type of the larger.
<p>
<b>Usage notes:</b> The <codeph>BITOR()</codeph> function is equivalent to the
<codeph>|</codeph> binary operator.
</p>
<p conref="../shared/impala_common.xml#common/return_type_same"/>
<p conref="../shared/impala_common.xml#common/added_in_230"/>
<p conref="../shared/impala_common.xml#common/example_blurb"/>
<p>
The following examples show the results of ORing integer values.
</p>
<codeblock>select bitor(1,4); /* 00000001 | 00000100 */
+-------------+
| bitor(1, 4) |
+-------------+
| 5 |
+-------------+
select bitor(16,48); /* 00001000 | 00011000 */
+---------------+
| bitor(16, 48) |
+---------------+
| 48 |
+---------------+
select bitor(0,7); /* 00000000 | 00000111 */
+-------------+
| bitor(0, 7) |
+-------------+
| 7 |
+-------------+
</codeblock>
</dd>
</dlentry>
<dlentry id="bitxor">
<dt>
BITXOR(integer_type a, same_type b)
</dt>
<dd>
<b>Purpose:</b> Returns an integer value representing the bits that are set to 1 in
one but not both of the arguments. If the arguments are of different sizes, the
smaller is promoted to the type of the larger.
<p>
<b>Usage notes:</b> The <codeph>BITXOR()</codeph> function is equivalent to the
<codeph>^</codeph> binary operator.
</p>
<p conref="../shared/impala_common.xml#common/return_type_same"/>
<p conref="../shared/impala_common.xml#common/added_in_230"/>
<p conref="../shared/impala_common.xml#common/example_blurb"/>
<p>
The following examples show the results of XORing integer values. XORing a non-zero
value with zero returns the non-zero value. XORing two identical values returns
zero, because all the 1 bits from the first argument are also 1 bits in the second
argument. XORing different non-zero values turns off some bits and leaves others
turned on, based on whether the same bit is set in both arguments.
</p>
<codeblock>select bitxor(0,15); /* 00000000 ^ 00001111 */
+---------------+
| bitxor(0, 15) |
+---------------+
| 15 |
+---------------+
select bitxor(7,7); /* 00000111 ^ 00000111 */
+--------------+
| bitxor(7, 7) |
+--------------+
| 0 |
+--------------+
select bitxor(8,4); /* 00001000 ^ 00000100 */
+--------------+
| bitxor(8, 4) |
+--------------+
| 12 |
+--------------+
select bitxor(3,7); /* 00000011 ^ 00000111 */
+--------------+
| bitxor(3, 7) |
+--------------+
| 4 |
+--------------+
</codeblock>
</dd>
</dlentry>
<dlentry id="countset">
<dt>
COUNTSET(integer_type a [, INT zero_or_one])
</dt>
<dd>
<b>Purpose:</b> By default, returns the number of 1 bits in the specified integer
value. If the optional second argument is set to zero, it returns the number of 0 bits
instead.
<p
conref="../shared/impala_common.xml#common/usage_notes_blurb"/>
<p>
In discussions of information theory, this operation is referred to as the
<q><xref
href="https://en.wikipedia.org/wiki/Hamming_weight"
scope="external" format="html">population
count</xref></q> or <q>popcount</q>.
</p>
<p conref="../shared/impala_common.xml#common/return_type_same"/>
<p conref="../shared/impala_common.xml#common/added_in_230"/>
<p conref="../shared/impala_common.xml#common/example_blurb"/>
<p>
The following examples show how to count the number of 1 bits in an integer value.
</p>
<codeblock>select countset(1); /* 00000001 */
+-------------+
| countset(1) |
+-------------+
| 1 |
+-------------+
select countset(3); /* 00000011 */
+-------------+
| countset(3) |
+-------------+
| 2 |
+-------------+
select countset(16); /* 00010000 */
+--------------+
| countset(16) |
+--------------+
| 1 |
+--------------+
select countset(17); /* 00010001 */
+--------------+
| countset(17) |
+--------------+
| 2 |
+--------------+
select countset(7,1); /* 00000111 = 3 1 bits; the function counts 1 bits by default */
+----------------+
| countset(7, 1) |
+----------------+
| 3 |
+----------------+
select countset(7,0); /* 00000111 = 5 0 bits; third argument can only be 0 or 1 */
+----------------+
| countset(7, 0) |
+----------------+
| 5 |
+----------------+
</codeblock>
</dd>
</dlentry>
<dlentry id="getbit">
<dt>
GETBIT(integer_type a, INT position)
</dt>
<dd>
<b>Purpose:</b> Returns a 0 or 1 representing the bit at a specified position. The
positions are numbered right to left, starting at zero. The position argument cannot
be negative.
<p
conref="../shared/impala_common.xml#common/usage_notes_blurb"/>
<p>
When you use a literal input value, it is treated as an 8-bit, 16-bit, and so on
value, the smallest type that is appropriate. The type of the input value limits the
range of the positions. Cast the input value to the appropriate type if you need to
ensure it is treated as a 64-bit, 32-bit, and so on value.
</p>
<p conref="../shared/impala_common.xml#common/return_type_same"/>
<p conref="../shared/impala_common.xml#common/added_in_230"/>
<p conref="../shared/impala_common.xml#common/example_blurb"/>
<p>
The following examples show how to test a specific bit within an integer value.
</p>
<codeblock>select getbit(1,0); /* 00000001 */
+--------------+
| getbit(1, 0) |
+--------------+
| 1 |
+--------------+
select getbit(16,1) /* 00010000 */
+---------------+
| getbit(16, 1) |
+---------------+
| 0 |
+---------------+
select getbit(16,4) /* 00010000 */
+---------------+
| getbit(16, 4) |
+---------------+
| 1 |
+---------------+
select getbit(16,5) /* 00010000 */
+---------------+
| getbit(16, 5) |
+---------------+
| 0 |
+---------------+
select getbit(-1,3); /* 11111111 */
+---------------+
| getbit(-1, 3) |
+---------------+
| 1 |
+---------------+
select getbit(-1,25); /* 11111111 */
ERROR: Invalid bit position: 25
select getbit(cast(-1 as int),25); /* 11111111111111111111111111111111 */
+-----------------------------+
| getbit(cast(-1 as int), 25) |
+-----------------------------+
| 1 |
+-----------------------------+
</codeblock>
</dd>
</dlentry>
<dlentry id="rotateleft">
<dt>
ROTATELEFT(integer_type a, INT positions)
</dt>
<dd>
<b>Purpose:</b> Rotates an integer value left by a specified number of bits. As the
most significant bit is taken out of the original value, if it is a 1 bit, it is
<q>rotated</q> back to the least significant bit. Therefore, the final value has the
same number of 1 bits as the original value, just in different positions. In computer
science terms, this operation is a
<q><xref
href="https://en.wikipedia.org/wiki/Circular_shift"
scope="external" format="html">circular
shift</xref></q>.
<p
conref="../shared/impala_common.xml#common/usage_notes_blurb"/>
<p>
Specifying a second argument of zero leaves the original value unchanged. Rotating a
-1 value by any number of positions still returns -1, because the original value has
all 1 bits and all the 1 bits are preserved during rotation. Similarly, rotating a 0
value by any number of positions still returns 0. Rotating a value by the same
number of bits as in the value returns the same value. Because this is a circular
operation, the number of positions is not limited to the number of bits in the input
value. For example, rotating an 8-bit value by 1, 9, 17, and so on positions returns
an identical result in each case.
</p>
<p conref="../shared/impala_common.xml#common/return_type_same"/>
<p conref="../shared/impala_common.xml#common/added_in_230"/>
<p conref="../shared/impala_common.xml#common/example_blurb"/>
<codeblock>select rotateleft(1,4); /* 00000001 -> 00010000 */
+------------------+
| rotateleft(1, 4) |
+------------------+
| 16 |
+------------------+
select rotateleft(-1,155); /* 11111111 -> 11111111 */
+---------------------+
| rotateleft(-1, 155) |
+---------------------+
| -1 |
+---------------------+
select rotateleft(-128,1); /* 10000000 -> 00000001 */
+---------------------+
| rotateleft(-128, 1) |
+---------------------+
| 1 |
+---------------------+
select rotateleft(-127,3); /* 10000001 -> 00001100 */
+---------------------+
| rotateleft(-127, 3) |
+---------------------+
| 12 |
+---------------------+
</codeblock>
</dd>
</dlentry>
<dlentry id="rotateright">
<dt>
ROTATERIGHT(integer_type a, INT positions)
</dt>
<dd>
<b>Purpose:</b> Rotates an integer value right by a specified number of bits. As the
least significant bit is taken out of the original value, if it is a 1 bit, it is
<q>rotated</q> back to the most significant bit. Therefore, the final value has the
same number of 1 bits as the original value, just in different positions. In computer
science terms, this operation is a
<q><xref
href="https://en.wikipedia.org/wiki/Circular_shift"
scope="external" format="html">circular
shift</xref></q>.
<p
conref="../shared/impala_common.xml#common/usage_notes_blurb"/>
<p>
Specifying a second argument of zero leaves the original value unchanged. Rotating a
-1 value by any number of positions still returns -1, because the original value has
all 1 bits and all the 1 bits are preserved during rotation. Similarly, rotating a 0
value by any number of positions still returns 0. Rotating a value by the same
number of bits as in the value returns the same value. Because this is a circular
operation, the number of positions is not limited to the number of bits in the input
value. For example, rotating an 8-bit value by 1, 9, 17, and so on positions returns
an identical result in each case.
</p>
<p conref="../shared/impala_common.xml#common/return_type_same"/>
<p conref="../shared/impala_common.xml#common/added_in_230"/>
<p conref="../shared/impala_common.xml#common/example_blurb"/>
<codeblock>select rotateright(16,4); /* 00010000 -> 00000001 */
+--------------------+
| rotateright(16, 4) |
+--------------------+
| 1 |
+--------------------+
select rotateright(-1,155); /* 11111111 -> 11111111 */
+----------------------+
| rotateright(-1, 155) |
+----------------------+
| -1 |
+----------------------+
select rotateright(-128,1); /* 10000000 -> 01000000 */
+----------------------+
| rotateright(-128, 1) |
+----------------------+
| 64 |
+----------------------+
select rotateright(-127,3); /* 10000001 -> 00110000 */
+----------------------+
| rotateright(-127, 3) |
+----------------------+
| 48 |
+----------------------+
</codeblock>
</dd>
</dlentry>
<dlentry id="setbit">
<dt>
SETBIT(integer_type a, INT position [, INT zero_or_one])
</dt>
<dd>
<b>Purpose:</b> By default, changes a bit at a specified position to a 1, if it is not
already. If the optional third argument is set to zero, the specified bit is set to 0
instead.
<p
conref="../shared/impala_common.xml#common/usage_notes_blurb"/>
If the bit at the specified position was already 1 (by default) or 0 (with a third
argument of zero), the return value is the same as the first argument. The positions
are numbered right to left, starting at zero. (Therefore, the return value could be
different from the first argument even if the position argument is zero.) The position
argument cannot be negative.
<p>
When you use a literal input value, it is treated as an 8-bit, 16-bit, and so on
value, the smallest type that is appropriate. The type of the input value limits the
range of the positions. Cast the input value to the appropriate type if you need to
ensure it is treated as a 64-bit, 32-bit, and so on value.
</p>
<p conref="../shared/impala_common.xml#common/return_type_same"/>
<p conref="../shared/impala_common.xml#common/added_in_230"/>
<p conref="../shared/impala_common.xml#common/example_blurb"/>
<codeblock>select setbit(0,0); /* 00000000 -> 00000001 */
+--------------+
| setbit(0, 0) |
+--------------+
| 1 |
+--------------+
select setbit(0,3); /* 00000000 -> 00001000 */
+--------------+
| setbit(0, 3) |
+--------------+
| 8 |
+--------------+
select setbit(7,3); /* 00000111 -> 00001111 */
+--------------+
| setbit(7, 3) |
+--------------+
| 15 |
+--------------+
select setbit(15,3); /* 00001111 -> 00001111 */
+---------------+
| setbit(15, 3) |
+---------------+
| 15 |
+---------------+
select setbit(0,32); /* By default, 0 is a TINYINT with only 8 bits. */
ERROR: Invalid bit position: 32
select setbit(cast(0 as bigint),32); /* For BIGINT, the position can be 0..63. */
+-------------------------------+
| setbit(cast(0 as bigint), 32) |
+-------------------------------+
| 4294967296 |
+-------------------------------+
select setbit(7,3,1); /* 00000111 -> 00001111; setting to 1 is the default */
+-----------------+
| setbit(7, 3, 1) |
+-----------------+
| 15 |
+-----------------+
select setbit(7,2,0); /* 00000111 -> 00000011; third argument of 0 clears instead of sets */
+-----------------+
| setbit(7, 2, 0) |
+-----------------+
| 3 |
+-----------------+
</codeblock>
</dd>
</dlentry>
<dlentry id="shiftleft">
<dt>
SHIFTLEFT(integer_type a, INT positions)
</dt>
<dd>
<b>Purpose:</b> Shifts an integer value left by a specified number of bits. As the
most significant bit is taken out of the original value, it is discarded and the least
significant bit becomes 0. In computer science terms, this operation is a
<q><xref
href="https://en.wikipedia.org/wiki/Logical_shift"
scope="external" format="html">logical
shift</xref></q>.
<p
conref="../shared/impala_common.xml#common/usage_notes_blurb"/>
<p>
The final value has either the same number of 1 bits as the original value, or
fewer. Shifting an 8-bit value by 8 positions, a 16-bit value by 16 positions, and
so on produces a result of zero.
</p>
<p>
Specifying a second argument of zero leaves the original value unchanged. Shifting
any value by 0 returns the original value. Shifting any value by 1 is the same as
multiplying it by 2, as long as the value is small enough; larger values eventually
become negative when shifted, as the sign bit is set. Starting with the value 1 and
shifting it left by N positions gives the same result as 2 to the Nth power, or
<codeph>POW(2,<varname>N</varname>)</codeph>.
</p>
<p conref="../shared/impala_common.xml#common/return_type_same"/>
<p conref="../shared/impala_common.xml#common/added_in_230"/>
<p conref="../shared/impala_common.xml#common/example_blurb"/>
<codeblock>select shiftleft(1,0); /* 00000001 -> 00000001 */
+-----------------+
| shiftleft(1, 0) |
+-----------------+
| 1 |
+-----------------+
select shiftleft(1,3); /* 00000001 -> 00001000 */
+-----------------+
| shiftleft(1, 3) |
+-----------------+
| 8 |
+-----------------+
select shiftleft(8,2); /* 00001000 -> 00100000 */
+-----------------+
| shiftleft(8, 2) |
+-----------------+
| 32 |
+-----------------+
select shiftleft(127,1); /* 01111111 -> 11111110 */
+-------------------+
| shiftleft(127, 1) |
+-------------------+
| -2 |
+-------------------+
select shiftleft(127,5); /* 01111111 -> 11100000 */
+-------------------+
| shiftleft(127, 5) |
+-------------------+
| -32 |
+-------------------+
select shiftleft(-1,4); /* 11111111 -> 11110000 */
+------------------+
| shiftleft(-1, 4) |
+------------------+
| -16 |
+------------------+
</codeblock>
</dd>
</dlentry>
<dlentry id="shiftright">
<dt>
SHIFTRIGHT(integer_type a, INT positions)
</dt>
<dd>
<b>Purpose:</b> Shifts an integer value right by a specified number of bits. As the
least significant bit is taken out of the original value, it is discarded and the most
significant bit becomes 0. In computer science terms, this operation is a
<q><xref
href="https://en.wikipedia.org/wiki/Logical_shift"
scope="external" format="html">logical
shift</xref></q>.
<p
conref="../shared/impala_common.xml#common/usage_notes_blurb"/>
<p>
Therefore, the final value has either the same number of 1 bits as the original
value, or fewer. Shifting an 8-bit value by 8 positions, a 16-bit value by 16
positions, and so on produces a result of zero.
</p>
<p>
Specifying a second argument of zero leaves the original value unchanged. Shifting
any value by 0 returns the original value. Shifting any positive value right by 1 is
the same as dividing it by 2. Negative values become positive when shifted right.
</p>
<p conref="../shared/impala_common.xml#common/return_type_same"/>
<p conref="../shared/impala_common.xml#common/added_in_230"/>
<p conref="../shared/impala_common.xml#common/example_blurb"/>
<codeblock>select shiftright(16,0); /* 00010000 -> 00010000 */
+-------------------+
| shiftright(16, 0) |
+-------------------+
| 16 |
+-------------------+
select shiftright(16,4); /* 00010000 -> 00000001 */
+-------------------+
| shiftright(16, 4) |
+-------------------+
| 1 |
+-------------------+
select shiftright(16,5); /* 00010000 -> 00000000 */
+-------------------+
| shiftright(16, 5) |
+-------------------+
| 0 |
+-------------------+
select shiftright(-1,1); /* 11111111 -> 01111111 */
+-------------------+
| shiftright(-1, 1) |
+-------------------+
| 127 |
+-------------------+
select shiftright(-1,5); /* 11111111 -> 00000111 */
+-------------------+
| shiftright(-1, 5) |
+-------------------+
| 7 |
+-------------------+
</codeblock>
</dd>
</dlentry>
</dl>
</conbody>
</concept>
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