1<!-- 2doc/src/sgml/ref/alter_opfamily.sgml 3PostgreSQL documentation 4--> 5 6<refentry id="sql-alteropfamily"> 7 <indexterm zone="sql-alteropfamily"> 8 <primary>ALTER OPERATOR FAMILY</primary> 9 </indexterm> 10 11 <refmeta> 12 <refentrytitle>ALTER OPERATOR FAMILY</refentrytitle> 13 <manvolnum>7</manvolnum> 14 <refmiscinfo>SQL - Language Statements</refmiscinfo> 15 </refmeta> 16 17 <refnamediv> 18 <refname>ALTER OPERATOR FAMILY</refname> 19 <refpurpose>change the definition of an operator family</refpurpose> 20 </refnamediv> 21 22 <refsynopsisdiv> 23<synopsis> 24ALTER OPERATOR FAMILY <replaceable>name</replaceable> USING <replaceable class="parameter">index_method</replaceable> ADD 25 { OPERATOR <replaceable class="parameter">strategy_number</replaceable> <replaceable class="parameter">operator_name</replaceable> ( <replaceable class="parameter">op_type</replaceable>, <replaceable class="parameter">op_type</replaceable> ) 26 [ FOR SEARCH | FOR ORDER BY <replaceable class="parameter">sort_family_name</replaceable> ] 27 | FUNCTION <replaceable class="parameter">support_number</replaceable> [ ( <replaceable class="parameter">op_type</replaceable> [ , <replaceable class="parameter">op_type</replaceable> ] ) ] 28 <replaceable class="parameter">function_name</replaceable> [ ( <replaceable class="parameter">argument_type</replaceable> [, ...] ) ] 29 } [, ... ] 30 31ALTER OPERATOR FAMILY <replaceable>name</replaceable> USING <replaceable class="parameter">index_method</replaceable> DROP 32 { OPERATOR <replaceable class="parameter">strategy_number</replaceable> ( <replaceable class="parameter">op_type</replaceable> [ , <replaceable class="parameter">op_type</replaceable> ] ) 33 | FUNCTION <replaceable class="parameter">support_number</replaceable> ( <replaceable class="parameter">op_type</replaceable> [ , <replaceable class="parameter">op_type</replaceable> ] ) 34 } [, ... ] 35 36ALTER OPERATOR FAMILY <replaceable>name</replaceable> USING <replaceable class="parameter">index_method</replaceable> 37 RENAME TO <replaceable>new_name</replaceable> 38 39ALTER OPERATOR FAMILY <replaceable>name</replaceable> USING <replaceable class="parameter">index_method</replaceable> 40 OWNER TO { <replaceable>new_owner</replaceable> | CURRENT_USER | SESSION_USER } 41 42ALTER OPERATOR FAMILY <replaceable>name</replaceable> USING <replaceable class="parameter">index_method</replaceable> 43 SET SCHEMA <replaceable>new_schema</replaceable> 44</synopsis> 45 </refsynopsisdiv> 46 47 <refsect1> 48 <title>Description</title> 49 50 <para> 51 <command>ALTER OPERATOR FAMILY</command> changes the definition of 52 an operator family. You can add operators and support functions 53 to the family, remove them from the family, 54 or change the family's name or owner. 55 </para> 56 57 <para> 58 When operators and support functions are added to a family with 59 <command>ALTER OPERATOR FAMILY</command>, they are not part of any 60 specific operator class within the family, but are just <quote>loose</quote> 61 within the family. This indicates that these operators and functions 62 are compatible with the family's semantics, but are not required for 63 correct functioning of any specific index. (Operators and functions 64 that are so required should be declared as part of an operator class, 65 instead; see <xref linkend="sql-createopclass"/>.) 66 <productname>PostgreSQL</productname> will allow loose members of a 67 family to be dropped from the family at any time, but members of an 68 operator class cannot be dropped without dropping the whole class and 69 any indexes that depend on it. 70 Typically, single-data-type operators 71 and functions are part of operator classes because they are needed to 72 support an index on that specific data type, while cross-data-type 73 operators and functions are made loose members of the family. 74 </para> 75 76 <para> 77 You must be a superuser to use <command>ALTER OPERATOR FAMILY</command>. 78 (This restriction is made because an erroneous operator family definition 79 could confuse or even crash the server.) 80 </para> 81 82 <para> 83 <command>ALTER OPERATOR FAMILY</command> does not presently check 84 whether the operator family definition includes all the operators and 85 functions required by the index method, nor whether the operators and 86 functions form a self-consistent set. It is the user's 87 responsibility to define a valid operator family. 88 </para> 89 90 <para> 91 Refer to <xref linkend="xindex"/> for further information. 92 </para> 93 </refsect1> 94 95 <refsect1> 96 <title>Parameters</title> 97 98 <variablelist> 99 <varlistentry> 100 <term><replaceable class="parameter">name</replaceable></term> 101 <listitem> 102 <para> 103 The name (optionally schema-qualified) of an existing operator 104 family. 105 </para> 106 </listitem> 107 </varlistentry> 108 109 <varlistentry> 110 <term><replaceable class="parameter">index_method</replaceable></term> 111 <listitem> 112 <para> 113 The name of the index method this operator family is for. 114 </para> 115 </listitem> 116 </varlistentry> 117 118 <varlistentry> 119 <term><replaceable class="parameter">strategy_number</replaceable></term> 120 <listitem> 121 <para> 122 The index method's strategy number for an operator 123 associated with the operator family. 124 </para> 125 </listitem> 126 </varlistentry> 127 128 <varlistentry> 129 <term><replaceable class="parameter">operator_name</replaceable></term> 130 <listitem> 131 <para> 132 The name (optionally schema-qualified) of an operator associated 133 with the operator family. 134 </para> 135 </listitem> 136 </varlistentry> 137 138 <varlistentry> 139 <term><replaceable class="parameter">op_type</replaceable></term> 140 <listitem> 141 <para> 142 In an <literal>OPERATOR</literal> clause, 143 the operand data type(s) of the operator, or <literal>NONE</literal> to 144 signify a left-unary or right-unary operator. Unlike the comparable 145 syntax in <command>CREATE OPERATOR CLASS</command>, the operand data types 146 must always be specified. 147 </para> 148 149 <para> 150 In an <literal>ADD FUNCTION</literal> clause, the operand data type(s) the 151 function is intended to support, if different from 152 the input data type(s) of the function. For B-tree comparison functions 153 and hash functions it is not necessary to specify <replaceable 154 class="parameter">op_type</replaceable> since the function's input 155 data type(s) are always the correct ones to use. For B-tree sort 156 support functions, B-Tree equal image functions, and all 157 functions in GiST, SP-GiST and GIN operator classes, it is 158 necessary to specify the operand data type(s) the function is to 159 be used with. 160 </para> 161 162 <para> 163 In a <literal>DROP FUNCTION</literal> clause, the operand data type(s) the 164 function is intended to support must be specified. 165 </para> 166 </listitem> 167 </varlistentry> 168 169 <varlistentry> 170 <term><replaceable class="parameter">sort_family_name</replaceable></term> 171 <listitem> 172 <para> 173 The name (optionally schema-qualified) of an existing <literal>btree</literal> operator 174 family that describes the sort ordering associated with an ordering 175 operator. 176 </para> 177 178 <para> 179 If neither <literal>FOR SEARCH</literal> nor <literal>FOR ORDER BY</literal> is 180 specified, <literal>FOR SEARCH</literal> is the default. 181 </para> 182 </listitem> 183 </varlistentry> 184 185 <varlistentry> 186 <term><replaceable class="parameter">support_number</replaceable></term> 187 <listitem> 188 <para> 189 The index method's support function number for a 190 function associated with the operator family. 191 </para> 192 </listitem> 193 </varlistentry> 194 195 <varlistentry> 196 <term><replaceable class="parameter">function_name</replaceable></term> 197 <listitem> 198 <para> 199 The name (optionally schema-qualified) of a function that is an index 200 method support function for the operator family. If no argument list 201 is specified, the name must be unique in its schema. 202 </para> 203 </listitem> 204 </varlistentry> 205 206 <varlistentry> 207 <term><replaceable class="parameter">argument_type</replaceable></term> 208 <listitem> 209 <para> 210 The parameter data type(s) of the function. 211 </para> 212 </listitem> 213 </varlistentry> 214 215 <varlistentry> 216 <term><replaceable class="parameter">new_name</replaceable></term> 217 <listitem> 218 <para> 219 The new name of the operator family. 220 </para> 221 </listitem> 222 </varlistentry> 223 224 <varlistentry> 225 <term><replaceable class="parameter">new_owner</replaceable></term> 226 <listitem> 227 <para> 228 The new owner of the operator family. 229 </para> 230 </listitem> 231 </varlistentry> 232 233 <varlistentry> 234 <term><replaceable class="parameter">new_schema</replaceable></term> 235 <listitem> 236 <para> 237 The new schema for the operator family. 238 </para> 239 </listitem> 240 </varlistentry> 241 </variablelist> 242 243 <para> 244 The <literal>OPERATOR</literal> and <literal>FUNCTION</literal> 245 clauses can appear in any order. 246 </para> 247 248 </refsect1> 249 250 <refsect1> 251 <title>Notes</title> 252 253 <para> 254 Notice that the <literal>DROP</literal> syntax only specifies the <quote>slot</quote> 255 in the operator family, by strategy or support number and input data 256 type(s). The name of the operator or function occupying the slot is not 257 mentioned. Also, for <literal>DROP FUNCTION</literal> the type(s) to specify 258 are the input data type(s) the function is intended to support; for 259 GiST, SP-GiST and GIN indexes this might have nothing to do with the actual 260 input argument types of the function. 261 </para> 262 263 <para> 264 Because the index machinery does not check access permissions on functions 265 before using them, including a function or operator in an operator family 266 is tantamount to granting public execute permission on it. This is usually 267 not an issue for the sorts of functions that are useful in an operator 268 family. 269 </para> 270 271 <para> 272 The operators should not be defined by SQL functions. A SQL function 273 is likely to be inlined into the calling query, which will prevent 274 the optimizer from recognizing that the query matches an index. 275 </para> 276 277 <para> 278 Before <productname>PostgreSQL</productname> 8.4, the <literal>OPERATOR</literal> 279 clause could include a <literal>RECHECK</literal> option. This is no longer 280 supported because whether an index operator is <quote>lossy</quote> is now 281 determined on-the-fly at run time. This allows efficient handling of 282 cases where an operator might or might not be lossy. 283 </para> 284 </refsect1> 285 286 <refsect1> 287 <title>Examples</title> 288 289 <para> 290 The following example command adds cross-data-type operators and 291 support functions to an operator family that already contains B-tree 292 operator classes for data types <type>int4</type> and <type>int2</type>. 293 </para> 294 295<programlisting> 296ALTER OPERATOR FAMILY integer_ops USING btree ADD 297 298 -- int4 vs int2 299 OPERATOR 1 < (int4, int2) , 300 OPERATOR 2 <= (int4, int2) , 301 OPERATOR 3 = (int4, int2) , 302 OPERATOR 4 >= (int4, int2) , 303 OPERATOR 5 > (int4, int2) , 304 FUNCTION 1 btint42cmp(int4, int2) , 305 306 -- int2 vs int4 307 OPERATOR 1 < (int2, int4) , 308 OPERATOR 2 <= (int2, int4) , 309 OPERATOR 3 = (int2, int4) , 310 OPERATOR 4 >= (int2, int4) , 311 OPERATOR 5 > (int2, int4) , 312 FUNCTION 1 btint24cmp(int2, int4) ; 313</programlisting> 314 315 <para> 316 To remove these entries again: 317 </para> 318 319<programlisting> 320ALTER OPERATOR FAMILY integer_ops USING btree DROP 321 322 -- int4 vs int2 323 OPERATOR 1 (int4, int2) , 324 OPERATOR 2 (int4, int2) , 325 OPERATOR 3 (int4, int2) , 326 OPERATOR 4 (int4, int2) , 327 OPERATOR 5 (int4, int2) , 328 FUNCTION 1 (int4, int2) , 329 330 -- int2 vs int4 331 OPERATOR 1 (int2, int4) , 332 OPERATOR 2 (int2, int4) , 333 OPERATOR 3 (int2, int4) , 334 OPERATOR 4 (int2, int4) , 335 OPERATOR 5 (int2, int4) , 336 FUNCTION 1 (int2, int4) ; 337</programlisting> 338 </refsect1> 339 340 <refsect1> 341 <title>Compatibility</title> 342 343 <para> 344 There is no <command>ALTER OPERATOR FAMILY</command> statement in 345 the SQL standard. 346 </para> 347 </refsect1> 348 349 <refsect1> 350 <title>See Also</title> 351 352 <simplelist type="inline"> 353 <member><xref linkend="sql-createopfamily"/></member> 354 <member><xref linkend="sql-dropopfamily"/></member> 355 <member><xref linkend="sql-createopclass"/></member> 356 <member><xref linkend="sql-alteropclass"/></member> 357 <member><xref linkend="sql-dropopclass"/></member> 358 </simplelist> 359 </refsect1> 360</refentry> 361