com.bigdata.rdf.sparql.ast.eval

Interface AST2BOpBase.Annotations

All Known Subinterfaces:

AbstractOptimizerTestCase.Annotations, AST2BOpRTO.Annotations, ASTStaticJoinOptimizer.Annotations

Enclosing class:

AST2BOpBase

public static interface AST2BOpBase.Annotations

Annotations used to mark named and default graph patterns on the IPredicates. Rather than attaching a named or default graph expander, we annotate the predicate with the metadata for the access path and then convert that annotation to the appropriate pipeline operators.

Field Summary

Fields

Modifier and Type	Field and Description
static String	AUTO_COMMIT Boolean indicating whether the AST2BOpUpdate should autocommit.
static String	COST_SCAN The estimated cost of a SCAN + FILTER approach to a default graph or named graph query.
static String	COST_SUBQUERY A SubqueryCostReport on the estimated cost of a SUBQUERY approach to a default graph or named graph query.
static String	DATASET The Dataset associated with the access path (quads mode only).
static boolean	DEFAULT_QUADS
static String	ESTIMATED_CARDINALITY The estimated cardinality of an access path as determined during static query optimization.
static String	NKNOWN The #of known graphs in the Dataset for a default graph or named graph query.
static String	ORIGINAL_INDEX The original index assigned to the access path by the static query optimizer.
static String	QUADS Boolean flag indicates that the database is operating in quads mode.
static String	SCOPE The StatementPattern.Scope of the access path (quads mode only).
static String	SIMPLE_JOIN Boolean annotation indicates whether the generated JOIN is simple (a single JOIN operator with optional constraints but without any variable materialization requirements) or complex (a JOIN operator associated with at least one constraint which requires the materialization of variables that are not already known to be materialized).

Field Detail

QUADS

static final String QUADS

Boolean flag indicates that the database is operating in quads mode.

DEFAULT_QUADS

static final boolean DEFAULT_QUADS

See Also:

Constant Field Values

DATASET

static final String DATASET

The Dataset associated with the access path (quads mode only). The Dataset is only provided by openrdf when FROM or FROM NAMED was used in the query. Otherwise the Dataset will be null and is not attached as an annotation.

Note: This annotation MUST be stripped from the query plan to prevent an attempt to serialized it for RMI in scale-out (the Dataset is not Serializable, can be quite large, and is captured by other constructions in the generated query plan).

SCOPE

static final String SCOPE

The StatementPattern.Scope of the access path (quads mode only). In quads mode the StatementPattern.Scope is always provided by openrdf.

See Also:

StatementPattern.Scope.NAMED_CONTEXTS, StatementPattern.Scope.DEFAULT_CONTEXTS

SIMPLE_JOIN

static final String SIMPLE_JOIN

Boolean annotation indicates whether the generated JOIN is simple (a single JOIN operator with optional constraints but without any variable materialization requirements) or complex (a JOIN operator associated with at least one constraint which requires the materialization of variables that are not already known to be materialized).

ORIGINAL_INDEX

static final String ORIGINAL_INDEX

The original index assigned to the access path by the static query optimizer.

Note: The actual index will be chosen at runtime based on the asBound predicate. In scale-out, the binding sets are send to the node having the shard on which the asBound predicate would read. TODO It would make sense to lift this annotation into a different AST optimizer so it is always present. An optimization for index locality for as-bound evaluation depends on the presence of this annotation.

See Also:

Choosing the index for testing fully bound access paths based on index locality

ESTIMATED_CARDINALITY

static final String ESTIMATED_CARDINALITY

The estimated cardinality of an access path as determined during static query optimization. This is the fast range count if the predicate and Long.MAX_VALUE if the predicate is part of an optional join (this is used by the query optimized to order the optional joins to the end since they can not increase the selectivity of the query).

COST_SCAN

static final String COST_SCAN

The estimated cost of a SCAN + FILTER approach to a default graph or named graph query.

COST_SUBQUERY

static final String COST_SUBQUERY

A SubqueryCostReport on the estimated cost of a SUBQUERY approach to a default graph or named graph query.

NKNOWN

static final String NKNOWN

The #of known graphs in the Dataset for a default graph or named graph query.

AUTO_COMMIT

static final String AUTO_COMMIT

Boolean indicating whether the AST2BOpUpdate should autocommit. Default value is TRUE.