Wiki / Operator Families / B-tree classes

btree/float4_ops (class)

B-tree operator class for float4; member of float_ops.

Reading PostgreSQL 18.6.

Description

B-tree operator class for float4; member of float_ops.

Object kind: Operator class
Index AM: B-tree
Input type: float4
Stored key type: Same as input type (catalog zero)
Default class: yes

Usage

btree/float4_ops

Operator classes and families

An index definition can specify an operator class for each column of an index.

The operator class identifies the operators to be used by the index for that column. For example, a B-tree index on the type int4 would use the int4_ops class; this operator class includes comparison functions for values of type int4 . In practice the default operator class for the column's data type is usually sufficient. The main reason for having operator classes is that for some data types, there could be more than one meaningful index behavior. For example, we might want to sort a complex-number data type either by absolute value or by real part. We could do this by defining two operator classes for the data type and then selecting the proper class when making an index. The operator class determines the basic sort ordering (which can then be modified by adding sort options COLLATE , ASC / DESC and/or NULLS FIRST / NULLS LAST ).

There are also some built-in operator classes besides the default ones:

Family operator strategies

Operator overload	Strategy	Purpose	Membership scope	Source description
<(float4,float4)	1	search	Class input pair	less than
<=(float4,float4)	2	search	Class input pair	less than or equal
=(float4,float4)	3	search	Class input pair	equal
>=(float4,float4)	4	search	Class input pair	greater than or equal
>(float4,float4)	5	search	Class input pair	greater than
<(float4,float8)	1	search	Family member	less than
<=(float4,float8)	2	search	Family member	less than or equal
=(float4,float8)	3	search	Family member	equal
>=(float4,float8)	4	search	Family member	greater than or equal
>(float4,float8)	5	search	Family member	greater than
<(float8,float8)	1	search	Family member	less than
<=(float8,float8)	2	search	Family member	less than or equal
=(float8,float8)	3	search	Family member	equal
>=(float8,float8)	4	search	Family member	greater than or equal
>(float8,float8)	5	search	Family member	greater than
<(float8,float4)	1	search	Family member	less than
<=(float8,float4)	2	search	Family member	less than or equal
=(float8,float4)	3	search	Family member	equal
>=(float8,float4)	4	search	Family member	greater than or equal
>(float8,float4)	5	search	Family member	greater than

Family support functions

Support number	Left type	Right type	Function signature	Result type
1	float4	float4	btfloat4cmp(float4,float4)	int4
2	float4	float4	btfloat4sortsupport(internal)	void
1	float4	float8	btfloat48cmp(float4,float8)	int4
1	float8	float8	btfloat8cmp(float8,float8)	int4
2	float8	float8	btfloat8sortsupport(internal)	void
1	float8	float4	btfloat84cmp(float8,float4)	int4
3	float8	float8	in_range(float8,float8,float8,bool,bool)	bool
3	float4	float8	in_range(float4,float4,float8,bool,bool)	bool

Classes in this family

Class	Input type	Key type	Default
float4_ops	float4	Same as input type	yes
float8_ops	float8	Same as input type	yes

Related entries

Documentation and source

Source build

Version: 18.6
Build: https://ftp.postgresql.org/pub/source/v18.6/postgresql-18.6.tar.bz2
Source fingerprint: 555610c24d53e4316da5b7d3fc25c279d96856d5e0e23ee308c328c5fa881d9f

Compare versions

PostgreSQL 10 → 11: changed.

--- PostgreSQL 10
+++ PostgreSQL 11
@@ -282,6 +282,24 @@
       "number": "2",
       "result_type": "void",
       "right_type": "float8"
+    },
+    {
+      "family": "float_ops",
+      "function": "in_range(float4,float4,float8,bool,bool)",
+      "left_type": "float4",
+      "method": "btree",
+      "number": "3",
+      "result_type": "bool",
+      "right_type": "float8"
+    },
+    {
+      "family": "float_ops",
+      "function": "in_range(float8,float8,float8,bool,bool)",
+      "left_type": "float8",
+      "method": "btree",
+      "number": "3",
+      "result_type": "bool",
+      "right_type": "float8"
     }
   ]
 }

Compares recorded interfaces and attributes. Source fingerprints and build metadata are excluded; an absent sample is not proof of the introduction or removal release.

Related entries

Export JSON · Back to Operator Families · Recorded in PostgreSQL 10 through 20; the first sample is not necessarily its introduction.