@@ -904,14 +904,32 @@ pgbench <optional> <replaceable>options</replaceable> </optional> <replaceable>d
904904 <para>
905905 Sets variable <replaceable>varname</replaceable> to a value calculated
906906 from <replaceable>expression</replaceable>.
907- The expression may contain integer constants such as <literal>5432</literal>,
907+ The expression may contain the <literal>NULL</literal> constant,
908+ boolean constants <literal>TRUE</literal> and <literal>FALSE</literal>,
909+ integer constants such as <literal>5432</literal>,
908910 double constants such as <literal>3.14159</literal>,
909911 references to variables <literal>:</literal><replaceable>variablename</replaceable>,
910- unary operators (<literal>+</literal>, <literal>-</literal>) and binary operators
911- (<literal>+</literal>, <literal>-</literal>, <literal>*</literal>, <literal>/</literal>,
912- <literal>%</literal>) with their usual precedence and associativity,
913- <link linkend="pgbench-builtin-functions">function calls</link>, and 914- parentheses.
912+ <link linkend="pgbench-builtin-operators">operators</link>
913+ with their usual SQL precedence and associativity,
914+ <link linkend="pgbench-builtin-functions">function calls</link>,
915+ SQL <link linkend="functions-case"><token>CASE</token> generic conditional
916+ expressions</link> and parentheses.
917+ </para>
918+
919+ <para>
920+ Functions and most operators return <literal>NULL</literal> on
921+ <literal>NULL</literal> input.
922+ </para>
923+
924+ <para>
925+ For conditional purposes, non zero numerical values are
926+ <literal>TRUE</literal>, zero numerical values and <literal>NULL</literal>
927+ are <literal>FALSE</literal>.
928+ </para>
929+
930+ <para>
931+ When no final <token>ELSE</token> clause is provided to a
932+ <token>CASE</token>, the default value is <literal>NULL</literal>.
915933 </para>
916934
917935 <para>
@@ -920,6 +938,7 @@ pgbench <optional> <replaceable>options</replaceable> </optional> <replaceable>d
920938\set ntellers 10 * :scale
921939\set aid (1021 * random(1, 100000 * :scale)) % \
922940 (100000 * :scale) + 1
941+ \set divx CASE WHEN :x <> 0 THEN :y/:x ELSE NULL END
923942</programlisting></para>
924943 </listitem>
925944 </varlistentry>
@@ -996,6 +1015,177 @@ pgbench <optional> <replaceable>options</replaceable> </optional> <replaceable>d
9961015 </variablelist>
9971016 </refsect2>
9981017
1018+ <refsect2 id="pgbench-builtin-operators">
1019+ <title>Built-In Operators</title>
1020+
1021+ <para>
1022+ The arithmetic, bitwise, comparison and logical operators listed in
1023+ <xref linkend="pgbench-operators"/> are built into <application>pgbench</application>
1024+ and may be used in expressions appearing in
1025+ <link linkend="pgbench-metacommand-set"><literal>\set</literal></link>.
1026+ </para>
1027+
1028+ <table id="pgbench-operators">
1029+ <title>pgbench Operators by increasing precedence</title>
1030+ <tgroup cols="4">
1031+ <thead>
1032+ <row>
1033+ <entry>Operator</entry>
1034+ <entry>Description</entry>
1035+ <entry>Example</entry>
1036+ <entry>Result</entry>
1037+ </row>
1038+ </thead>
1039+ <tbody>
1040+ <row>
1041+ <entry><literal>OR</literal></entry>
1042+ <entry>logical or</entry>
1043+ <entry><literal>5 or 0</literal></entry>
1044+ <entry><literal>TRUE</literal></entry>
1045+ </row>
1046+ <row>
1047+ <entry><literal>AND</literal></entry>
1048+ <entry>logical and</entry>
1049+ <entry><literal>3 and 0</literal></entry>
1050+ <entry><literal>FALSE</literal></entry>
1051+ </row>
1052+ <row>
1053+ <entry><literal>NOT</literal></entry>
1054+ <entry>logical not</entry>
1055+ <entry><literal>not false</literal></entry>
1056+ <entry><literal>TRUE</literal></entry>
1057+ </row>
1058+ <row>
1059+ <entry><literal>IS [NOT] (NULL|TRUE|FALSE)</literal></entry>
1060+ <entry>value tests</entry>
1061+ <entry><literal>1 is null</literal></entry>
1062+ <entry><literal>FALSE</literal></entry>
1063+ </row>
1064+ <row>
1065+ <entry><literal>ISNULL|NOTNULL</literal></entry>
1066+ <entry>null tests</entry>
1067+ <entry><literal>1 notnull</literal></entry>
1068+ <entry><literal>TRUE</literal></entry>
1069+ </row>
1070+ <row>
1071+ <entry><literal>=</literal></entry>
1072+ <entry>is equal</entry>
1073+ <entry><literal>5 = 4</literal></entry>
1074+ <entry><literal>FALSE</literal></entry>
1075+ </row>
1076+ <row>
1077+ <entry><literal><></literal></entry>
1078+ <entry>is not equal</entry>
1079+ <entry><literal>5 <> 4</literal></entry>
1080+ <entry><literal>TRUE</literal></entry>
1081+ </row>
1082+ <row>
1083+ <entry><literal>!=</literal></entry>
1084+ <entry>is not equal</entry>
1085+ <entry><literal>5 != 5</literal></entry>
1086+ <entry><literal>FALSE</literal></entry>
1087+ </row>
1088+ <row>
1089+ <entry><literal><</literal></entry>
1090+ <entry>lower than</entry>
1091+ <entry><literal>5 < 4</literal></entry>
1092+ <entry><literal>FALSE</literal></entry>
1093+ </row>
1094+ <row>
1095+ <entry><literal><=</literal></entry>
1096+ <entry>lower or equal</entry>
1097+ <entry><literal>5 <= 4</literal></entry>
1098+ <entry><literal>FALSE</literal></entry>
1099+ </row>
1100+ <row>
1101+ <entry><literal>></literal></entry>
1102+ <entry>greater than</entry>
1103+ <entry><literal>5 > 4</literal></entry>
1104+ <entry><literal>TRUE</literal></entry>
1105+ </row>
1106+ <row>
1107+ <entry><literal>>=</literal></entry>
1108+ <entry>greater or equal</entry>
1109+ <entry><literal>5 >= 4</literal></entry>
1110+ <entry><literal>TRUE</literal></entry>
1111+ </row>
1112+ <row>
1113+ <entry><literal>|</literal></entry>
1114+ <entry>integer bitwise OR</entry>
1115+ <entry><literal>1 | 2</literal></entry>
1116+ <entry><literal>3</literal></entry>
1117+ </row>
1118+ <row>
1119+ <entry><literal>#</literal></entry>
1120+ <entry>integer bitwise XOR</entry>
1121+ <entry><literal>1 # 3</literal></entry>
1122+ <entry><literal>2</literal></entry>
1123+ </row>
1124+ <row>
1125+ <entry><literal>&</literal></entry>
1126+ <entry>integer bitwise AND</entry>
1127+ <entry><literal>1 & 3</literal></entry>
1128+ <entry><literal>1</literal></entry>
1129+ </row>
1130+ <row>
1131+ <entry><literal>~</literal></entry>
1132+ <entry>integer bitwise NOT</entry>
1133+ <entry><literal>~ 1</literal></entry>
1134+ <entry><literal>-2</literal></entry>
1135+ </row>
1136+ <row>
1137+ <entry><literal><<</literal></entry>
1138+ <entry>integer bitwise shift left</entry>
1139+ <entry><literal>1 << 2</literal></entry>
1140+ <entry><literal>4</literal></entry>
1141+ </row>
1142+ <row>
1143+ <entry><literal>>></literal></entry>
1144+ <entry>integer bitwise shift right</entry>
1145+ <entry><literal>8 >> 2</literal></entry>
1146+ <entry><literal>2</literal></entry>
1147+ </row>
1148+ <row>
1149+ <entry><literal>+</literal></entry>
1150+ <entry>addition</entry>
1151+ <entry><literal>5 + 4</literal></entry>
1152+ <entry><literal>9</literal></entry>
1153+ </row>
1154+ <row>
1155+ <entry><literal>-</literal></entry>
1156+ <entry>substraction</entry>
1157+ <entry><literal>3 - 2.0</literal></entry>
1158+ <entry><literal>1.0</literal></entry>
1159+ </row>
1160+ <row>
1161+ <entry><literal>*</literal></entry>
1162+ <entry>multiplication</entry>
1163+ <entry><literal>5 * 4</literal></entry>
1164+ <entry><literal>20</literal></entry>
1165+ </row>
1166+ <row>
1167+ <entry><literal>/</literal></entry>
1168+ <entry>division (integer truncates the results)</entry>
1169+ <entry><literal>5 / 3</literal></entry>
1170+ <entry><literal>1</literal></entry>
1171+ </row>
1172+ <row>
1173+ <entry><literal>%</literal></entry>
1174+ <entry>modulo</entry>
1175+ <entry><literal>3 % 2</literal></entry>
1176+ <entry><literal>1</literal></entry>
1177+ </row>
1178+ <row>
1179+ <entry><literal>-</literal></entry>
1180+ <entry>opposite</entry>
1181+ <entry><literal>- 2.0</literal></entry>
1182+ <entry><literal>-2.0</literal></entry>
1183+ </row>
1184+ </tbody>
1185+ </tgroup>
1186+ </table>
1187+ </refsect2>
1188+
9991189 <refsect2 id="pgbench-builtin-functions">
10001190 <title>Built-In Functions</title>
10011191
@@ -1041,6 +1231,13 @@ pgbench <optional> <replaceable>options</replaceable> </optional> <replaceable>d
10411231 <entry><literal>double(5432)</literal></entry>
10421232 <entry><literal>5432.0</literal></entry>
10431233 </row>
1234+ <row>
1235+ <entry><literal><function>exp(<replaceable>x</replaceable>)</function></literal></entry>
1236+ <entry>double</entry>
1237+ <entry>exponential</entry>
1238+ <entry><literal>exp(1.0)</literal></entry>
1239+ <entry><literal>2.718281828459045</literal></entry>
1240+ </row>
10441241 <row>
10451242 <entry><literal><function>greatest(<replaceable>a</replaceable> [, <replaceable>...</replaceable> ] )</function></literal></entry>
10461243 <entry>double if any <replaceable>a</replaceable> is double, else integer</entry>
@@ -1062,6 +1259,20 @@ pgbench <optional> <replaceable>options</replaceable> </optional> <replaceable>d
10621259 <entry><literal>least(5, 4, 3, 2.1)</literal></entry>
10631260 <entry><literal>2.1</literal></entry>
10641261 </row>
1262+ <row>
1263+ <entry><literal><function>ln(<replaceable>x</replaceable>)</function></literal></entry>
1264+ <entry>double</entry>
1265+ <entry>natural logarithm</entry>
1266+ <entry><literal>ln(2.718281828459045)</literal></entry>
1267+ <entry><literal>1.0</literal></entry>
1268+ </row>
1269+ <row>
1270+ <entry><literal><function>mod(<replaceable>i</replaceable>, <replaceable>bj</replaceable>)</function></literal></entry>
1271+ <entry>integer</entry>
1272+ <entry>modulo</entry>
1273+ <entry><literal>mod(54, 32)</literal></entry>
1274+ <entry><literal>22</literal></entry>
1275+ </row>
10651276 <row>
10661277 <entry><literal><function>pi()</function></literal></entry>
10671278 <entry>double</entry>
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