-
Optionally, an operator class for BRIN can supply the
+
An operator class for BRIN can optionally specify the
following method:
void options(local_relopts *relopts)
- Defines set of user-visible parameters that control operator class
+ Defines a set of user-visible parameters that control operator class
behavior.
- The options function has given pointer to
+ The options function is passed a pointer to a
local_relopts struct, which needs to be
filled with a set of operator class specific options. The options
- can be accessed from other support functions using
+ can be accessed from other support functions using the
PG_HAS_OPCLASS_OPTIONS() and
PG_GET_OPCLASS_OPTIONS() macros.
- Since both key extraction for indexed value and representation of the
- key in
GIN are flexible,
it may depends on
+ Since both key extraction of indexed values and representation of the
+ key in
GIN are flexible,
they may depend on
user-specified parameters.
Optionally, a B-tree operator family may provide
options (operator class specific
options) support functions, registered under support
- function number 5. These functions define set of user-visible
+ function number 5. These functions define a set of user-visible
parameters that control operator class behavior.
options(relopts local_relopts *) returns void
- The function has given pointer to local_relopts
+ The function is passed a pointer to a local_relopts
struct, which needs to be filled with a set of operator class
specific options. The options can be accessed from other support
- functions using PG_HAS_OPCLASS_OPTIONS() and
+ functions using the PG_HAS_OPCLASS_OPTIONS() and
PG_GET_OPCLASS_OPTIONS() macros.
- Currently, no B-Tree operator class has options
+ Currently, no B-Tree operator class has an options
support function. B-tree doesn't allow flexible representation of keys
like GiST, SP-GiST, GIN and BRIN do. So, options
- probably doesn't have much usage in current shape of B-tree index
+ probably doesn't have much application in the current B-tree index
access method. Nevertheless, this support function was added to B-tree
- for uniformity, and probably it will found its usage during further
+ for uniformity, and will probably find uses during further
evolution of B-tree in
PostgreSQL.
- The options function has given pointer to
+ The options function is passed a pointer to a
local_relopts struct, which needs to be
- filled with s set of operator class specific options. The options
- can be accessed from other support functions using
+ filled with a set of operator class specific options. The options
+ can be accessed from other support functions using the
PG_HAS_OPCLASS_OPTIONS() and
PG_GET_OPCLASS_OPTIONS() macros.
- Since both key extraction for indexed value and representation of the
- key in
GIN are flexible,
it may depends on
+ Since both key extraction of indexed values and representation of the
+ key in
GIN are flexible,
they may depend on
user-specified parameters.
options
- Allows defintion of user-visible parameters that control operator
+ Allows definition of user-visible parameters that control operator
class behavior.
- The function has given pointer to local_relopts
+ The function is passed a pointer to a local_relopts
struct, which needs to be filled with a set of operator class
specific options. The options can be accessed from other support
- functions using PG_HAS_OPCLASS_OPTIONS() and
+ functions using the PG_HAS_OPCLASS_OPTIONS() and
PG_GET_OPCLASS_OPTIONS() macros.
- The sample implementation of my_option() and parameters usage
- in the another support function are given below:
+ An example implementation of my_options() and parameters use
+ from other support functions are given below:
typedef enum MyEnumType
int str_param; /* string parameter */
} MyOptionsStruct;
-/* String representations for enum values */
+/* String representation of enum values */
static relopt_enum_elt_def myEnumValues[] =
{
{"on", MY_ENUM_ON},
static char *str_param_default = "default";
/*
- * Sample validatior: checks that string is not longer than 8 bytes.
+ * Sample validator: checks that string is not longer than 8 bytes.
*/
static void
validate_my_string_relopt(const char *value)
Since the representation of the key in
GiST is
- flexible, it may depends on user-specified parameters. For instace,
- the length of key signature may be such parameter. See
+ flexible, it may depend on user-specified parameters. For instance,
+ the length of key signature may be specified. See
gtsvector_options() for example.
values for the support method, while the second argument is a pointer to a
C struct where output values must be placed. Four of the mandatory methods just
return void, since all their results appear in the output struct; but
- leaf_consistent additionally returns a boolean result.
+ leaf_consistent returns a boolean result.
The methods must not modify any fields of their input structs. In all
cases, the output struct is initialized to zeroes before calling the
user-defined method. The optional sixth method compress
- accepts datum to be indexed as the only argument and returns a value suitable
+ accepts a datum to be indexed as the only argument and returns a value suitable
for physical storage in a leaf tuple. The optional seventh method
- options accepts internal pointer to a C struct, where
+ options accepts an internal pointer to a C struct, where
opclass-specific parameters should be placed, and returns void.
- The function has given pointer to local_relopts
+ The function is passed a pointer to a local_relopts
struct, which needs to be filled with a set of operator class
specific options. The options can be accessed from other support
- functions using PG_HAS_OPCLASS_OPTIONS() and
+ functions using the PG_HAS_OPCLASS_OPTIONS() and
PG_GET_OPCLASS_OPTIONS() macros.
Since the representation of the key in
SP-GiST is
- flexible, it may depends on user-specified parameters.
+ flexible, it may depend on user-specified parameters.
- Additionally, some opclasses allow user to set specific parameters, which
- controls its behavior. Each builtin index access method have optional
- options support function, which defines set of
+ Additionally, some opclasses allow users to specify parameters which
+ control their behavior. Each builtin index access method has an optional
+ options support function, which defines a set of
opclass-specific parameters.
|
- Defines set of options that are specific for this operator class
+ Defines a set of options that are specific to this operator class
(optional)
5
|
- Defines set of options that are specific for this operator class
+ Defines a set of options that are specific to this operator class
(optional)
3
|
options
- Defines set of options that are specific for this operator class
+ Defines a set of options that are specific to this operator class
(optional)
10
|
options
- Defines set of options that are specific for this operator class
+ Defines a set of options that are specific to this operator class
(optional)
6
|
options
- Defines set of options that are specific for this operator class
+ Defines a set of options that are specific to this operator class
(optional)
7
|
options
- Defines set of options that are specific for this operator class
+ Defines a set of options that are specific to this operator class
(optional)
5