CREATE_OPERATOR_CLASS(7pg17)

📦 version 17.11, in opensuse-leap 16.0

💅 CREATE OPERATOR CLASS(7) — like, the whole manual page, bestie

okay so this is CREATE OPERATOR CLASS(7) from the PostgreSQL 17.11 docs and honestly? it's kind of a big deal. it's the page that teaches you how to define your very own operator class, which is the glow-up that lets a data type actually hang out with an index. stay with me, it's gonna slay 🎀

✨ NAME ✨

CREATE_OPERATOR_CLASS — define a new operator class 🦋

🌸 SYNOPSIS 🌸

CREATE OPERATOR CLASS name [ DEFAULT ] FOR TYPE data_type
  USING index_method [ FAMILY family_name ] AS
  {  OPERATOR strategy_number operator_name [ ( op_type, op_type ) ] [ FOR SEARCH | FOR ORDER BY sort_family_name ]
   | FUNCTION support_number [ ( op_type [ , op_type ] ) ] function_name ( argument_type [, ...] )
   | STORAGE storage_type
  } [, ... ]

like, that's the whole recipe. screenshot it, bestie 📸

💖 DESCRIPTION 💖

CREATE OPERATOR CLASS creates a new operator class. no cap. an operator class is basically the situationship contract between a data type and an index — it defines how a particular data type can be used with an index ✨

the operator class specifies that certain operators will fill particular roles or “strategies” for this data type and this index method. and it also specifies the support functions that the index method should use when this operator class gets picked for an index column. 💅

⚠️ the one rule: every single operator and function used by an operator class must already be defined before you can create the operator class. no pre-registering your faves, they have to exist first, periodt.

if you give a schema name, the operator class gets created in that schema. otherwise it's created in the current schema (the default vibe). two operator classes in the same schema can share a name only if they're for different index methods — otherwise it's giving identity theft 🫶

the user who defines an operator class becomes its owner. and presently, the creating user must be a superuser. (that restriction exists because an erroneous operator class definition could confuse or even crash the server 😭 yeah, crash it. so, y'know, respect the power.)

CREATE OPERATOR CLASS does not presently check whether the definition includes all the operators and functions required by the index method, nor whether the operators and functions form a self-consistent set. it is the user's responsibility to define a valid operator class. so like… the training wheels are off, bestie, you're the main character now 👑

related operator classes can be grouped into operator families. to add a new operator class to an existing family, just specify the FAMILY option in CREATE OPERATOR CLASS. without that option, the new class gets placed into a family named the same as the new class — and that family gets created if it doesn't already exist. cute, right? 🌈

refer to Section 36.16 for further information 📚

🎀 PARAMETERS 🎀

  • name — the name of the operator class to be created. it can be schema-qualified 💫
  • DEFAULT — if present, the operator class becomes the default operator class for its data type. at most one operator class can be the default for a specific data type and index method. one. single. default. 👑
  • data_type — the column data type that this operator class is for.
  • index_method — the name of the index method this operator class is for.
  • family_name — the name of the existing operator family to add this operator class to. if not specified, a family named the same as the operator class is used (creating it, if it doesn't already exist).
  • strategy_number — the index method's strategy number for an operator associated with the operator class.
  • operator_name — the name (optionally schema-qualified) of an operator associated with the operator class.
  • op_type — in an OPERATOR clause: the operand data type(s) of the operator, or NONE to signify a prefix operator. the operand data types can be omitted in the normal case where they're the same as the operator class's data type. 🌀

in a FUNCTION clause: the operand data type(s) the function is intended to support, if different from the input data type(s) of the function (for B-tree comparison functions and hash functions) or the class's data type (for B-tree sort support functions, B-tree equal image functions, and all functions in GiST, SP-GiST, GIN and BRIN operator classes). these defaults are correct, and so op_type need not be specified in FUNCTION clauses — except for the case of a B-tree sort support function that is meant to support cross-data-type comparisons. iykyk 💅

  • sort_family_name — the name (optionally schema-qualified) of an existing btree operator family that describes the sort ordering associated with an ordering operator. and if neither FOR SEARCH nor FOR ORDER BY is specified, FOR SEARCH is the default. ✨
  • support_number — the index method's support function number for a function associated with the operator class.
  • function_name — the name (optionally schema-qualified) of a function that is an index method support function for the operator class.
  • argument_type — the parameter data type(s) of the function.
  • storage_type — the data type actually stored in the index. normally this is the same as the column data type, but some index methods (currently GiST, GIN, SP-GiST and BRIN) allow it to be different. the STORAGE clause must be omitted unless the index method allows a different type to be used. and if the column data_type is specified as anyarray, the storage_type can be declared as anyelement to indicate that the index entries are members of the element type belonging to the actual array type that each particular index is created for. 🍓

and the fun part: the OPERATOR, FUNCTION, and STORAGE clauses can appear in any order. mix and match, you do you 💐

⚠️ NOTES ⚠️

because the index machinery does not check access permissions on functions before using them, including a function or operator in an operator class is tantamount to granting public execute permission on it. 😳 this is usually not an issue for the sorts of functions that are useful in an operator class — but like, be aware, bestie.

the operators should not be defined by SQL functions. an SQL function is likely to be inlined into the calling query, which will prevent the optimizer from recognizing that the query matches an index. so… don't do that, fr fr. 💀

before PostgreSQL 8.4, the OPERATOR clause could include a RECHECK option. this is no longer supported, because whether an index operator is “lossy” is now determined on-the-fly at run time. this allows efficient handling of cases where an operator might or might not be lossy. glow-up behaviour honestly ✨

🔥 EXAMPLES 🔥

the following example command defines a GiST index operator class for the data type _int4 (array of int4). see the intarray module for the complete example. 🧚

CREATE OPERATOR CLASS gist__int_ops
    DEFAULT FOR TYPE _int4 USING gist AS
        OPERATOR        3       &&,
        OPERATOR        6       = (anyarray, anyarray),
        OPERATOR        7       @>,
        OPERATOR        8       <@,
        OPERATOR        20      @@ (_int4, query_int),
        FUNCTION        1       g_int_consistent (internal, _int4, smallint, oid, internal),
        FUNCTION        2       g_int_union (internal, internal),
        FUNCTION        3       g_int_compress (internal),
        FUNCTION        4       g_int_decompress (internal),
        FUNCTION        5       g_int_penalty (internal, internal, internal),
        FUNCTION        6       g_int_picksplit (internal, internal),
        FUNCTION        7       g_int_same (_int4, _int4, internal);

look at that. seven functions, five operators, one iconic little class. ate and left no crumbs 🍽️

🌈 COMPATIBILITY 🌈

CREATE OPERATOR CLASS is a PostgreSQL extension. there is no CREATE OPERATOR CLASS statement in the SQL standard. so it's not a "you're doing it wrong" situation — the standard just doesn't have one. 💜

🫶 SEE ALSO 🫶

and that's the whole page, bestie — go build something iconic with it 💅✨

sign-off szn: this lil masterpiece is from PostgreSQL 17.11, dated 2026, and it's the CREATE OPERATOR CLASS(7) page — mwah, take care, drink water, and remember to be a superuser responsibly 🎀🦋💖

📦 where this page comes from