Functions that build provenance circuit gates for semiring operations. More...

Functions
UUID	provsql.provenance_times (UUID[] tokens)
	Create a times (product) gate from multiple provenance tokens.
UUID	provsql.provenance_monus (UUID token1, UUID token2)
	Create a monus (difference) gate from two provenance tokens.
UUID	provsql.provenance_project (UUID token, INT[] positions)
	Create a project gate for where-provenance tracking.
UUID	provsql.provenance_eq (UUID token, INT pos1, INT pos2)
	Create an equijoin gate for where-provenance tracking.
UUID	provsql.provenance_plus (UUID[] tokens)
	Create a plus (sum) gate from an array of provenance tokens.
UUID	provsql.provenance_cmp (UUID left_token, OID comparison_op, UUID right_token)
	Create a comparison gate for HAVING clause provenance.
UUID	provsql.provenance_arith (INTEGER op, UUID[] children)
	Create an arithmetic gate over scalar-valued provenance children.

Detailed Description

Functions that build provenance circuit gates for semiring operations.

These are called internally by the query rewriter.

Function Documentation

◆ provenance_arith()

UUID provsql.provenance_arith	(	INTEGER	op,
		UUID[]	children )

Create an arithmetic gate over scalar-valued provenance children.

Builds a deterministic gate_arith from an operator tag and an ordered list of children. The tag is one of the provsql_arith_op ENUM values declared in src/provsql_utils.h (PLUS=0, TIMES=1, MINUS=2, DIV=3, NEG=4) and is stored in the gate's info1 field. Children must be UUIDs of scalar-producing gates (gate_rv, gate_value, or another gate_arith). The token UUID is derived deterministically from op and children so identical sub-expressions share their gate.

Parameters

op	Operator tag (`provsql_arith_op`).
children	Ordered list of child gate UUIDs.

Returns: UUID of the (possibly pre-existing) gate_arith.

Source code: provsql.sql line 922

◆ provenance_cmp()

UUID provsql.provenance_cmp	(	UUID	left_token,
		OID	comparison_op,
		UUID	right_token )

Create a comparison gate for HAVING clause provenance.

Parameters

left_token	provenance token for the left operand
comparison_op	OID of the comparison operator
right_token	provenance token for the right operand

Source code: provsql.sql line 879

◆ provenance_eq()

UUID provsql.provenance_eq	(	UUID	token,
		INT	pos1,
		INT	pos2 )

Create an equijoin gate for where-provenance tracking.

Parameters

token	child provenance token
pos1	attribute index in the first relation
pos2	attribute index in the second relation

Source code: provsql.sql line 821

◆ provenance_monus()

UUID provsql.provenance_monus	(	UUID	token1,
		UUID	token2 )

Create a monus (difference) gate from two provenance tokens.

Implements m-semiring monus. Returns token1 if token2 is NULL (used for LEFT OUTER JOIN semantics in the EXCEPT rewriting).

Source code: provsql.sql line 752

◆ provenance_plus()

UUID provsql.provenance_plus ( UUID[] tokens )

Create a plus (sum) gate from an array of provenance tokens.

Filters out NULL and zero-gates; returns gate_zero() if all tokens are trivial, or a single token if only one remains.

Source code: provsql.sql line 842

◆ provenance_project()

UUID provsql.provenance_project	(	UUID	token,
		INT[]	positions )

Create a project gate for where-provenance tracking.

Records the mapping between input and output attribute positions.

Parameters

token	child provenance token
positions	array encoding attribute position mappings

Source code: provsql.sql line 794

◆ provenance_times()

UUID provsql.provenance_times ( UUID[] tokens )

Create a times (product) gate from multiple provenance tokens.

Filters out NULL and one-gates; returns gate_one() if all tokens are trivial, or a single token if only one remains.

Source code: provsql.sql line 717