Gbase 8C system table PG_ amop

pg_amop The system table stores information about the association with the access method operator family . If an operator is a member of an operator family , Will occupy a row in this table . A family member is a search Operator or a ordering The operator . An operator can appear in multiple families , But it cannot appear in multiple search positions or sorting positions in a family .

name	type	quote	describe
oid	oid		Row identifier （ Hidden attribute , Must be explicitly selected to display ）
amopfamily	oid	pg_opfamily.oid	The operator family of this item
amoplefttype	oid	pg_type.oid	The left hand input data type of the operator
amoprighttype	oid	pg_type.oid	The right hand input data type of the operator
amopstrategy	int2		Operator policy number
amoppurpose	char		Operation compliant ,s Represent search ,o Indicates sort
amopopr	oid	pg_operator.oid	Operator OID
amopmethod	oid	pg_am.oid	Use the index access method of this operator family
amopsortfamily	oid	pg_opfamily.oid	If it is a sort operator , This item will be based on this B Tree operator family sort , If it is a search operator, it is 0

search The operator indicates that an index of this operator family can be searched , Find all the satisfaction WHERE indexed_column operator constant The line of . obviously , Such an operator must return a Boolean value , And its left input type must match the field data type of the index .

ordering The operator indicates that an index of this operator family can be scanned , Return to ORDER BYindexed_column operator constant Rows represented in sequence . Such an operator can return any sortable data type , Its left input type must also match the field data type of the index . ORDER BY The exact semantics of is by amopsortfamily Field specified , This field must refer to a... For the return type of the operator btree Operator family .