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Package rdflib :: Package store :: Package FOPLRelationalModel :: Module BinaryRelationPartition :: Class BinaryRelationPartition
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Type BinaryRelationPartition

object --+
         |
        BinaryRelationPartition

Known Subclasses:
AssociativeBox, NamedBinaryRelations, NamedLiteralProperties
The common ancestor of the three partitions for assertions.
Implements behavior common to all 3.  Each subclass is expected to define the following:

nameSuffix - The suffix appended to the name of the table
termEnumerations - a 4 item list (for each quad 'slot') of lists (or None) which enumerate the allowable term types
                   for each quad slot (one of 'U' - URIs,'V' - Variable,'L' - Literals,'B' - BNodes,'F' - Formulae)
columnNames - a list of column names for each quad slot (can be of additional length where each item is a 3-item tuple of:
              column name, column type, index)
columnIntersectionList - a list of 2 item tuples (the quad index and a boolean indicating whether or not the associated term is an identifier)
                         this list (the order of which is very important) is used for generating intersections between the partition and the identifier / value hash
hardCodedResultFields - a dictionary mapping quad slot indices to their hardcoded value (for partitions - such as ABOX - which have a hardcoded value for a particular quad slot)
hardCodedResultTermsTypes - a dictionary mapping quad slot indices to their hardcoded term type (for partitions - such as Literal properties - which have hardcoded values for a particular quad slot's term type)
Method Summary
  __init__(self, identifier, idHash, valueHash)
  __repr__(self)
  createSQL(self)
Generates a CREATE TABLE statement which creates a SQL table used for persisting assertions associated with this partition
  flushInsertions(self, db)
Adds the pending identifiers / values and assertions (using executemany for maximum efficiency), and resets the queue.
  foreignKeySQL(self, slot)
Generates foreign key expression relating a particular quad term with the identifier hash
  generateHashIntersections(self)
Generates the SQL JOINS (INNER and LEFT) used to intersect the identifier and value hashes with this partition.
  generateWhereClause(self, queryPattern)
Takes a query pattern (a list of quad terms - subject,predicate,object,context) and generates a SQL WHERE clauses which works in conjunction to the intersections to filter the result set by partial matching (by REGEX), full matching (by integer half-hash), and term types.
  IndexManagementSQL(self, create)
  insertRelations(self, quadSlots)
Takes a list of QuadSlot objects and queues the new identifiers / values to insert and the assertions as well (so they can be added in a batch for maximum efficiency)
  insertRelationsSQLCMD(self)
Generates a SQL command with parameter references (%s) in order to facilitate efficient batch insertion of multiple assertions by Python DB implementations (such as MySQLdb)
  selectContextFields(self, first)
Generates a list of column aliases for the SELECT SQL command used in order to fetch contexts from each partition
  selectFields(self, first)
Returns a list of column aliases for the SELECT SQL command used to fetch quads from a partition
    Inherited from object
  __delattr__(...)
x.__delattr__('name') <==> del x.name
  __getattribute__(...)
x.__getattribute__('name') <==> x.name
  __hash__(x)
x.__hash__() <==> hash(x)
  __new__(T, S, ...)
T.__new__(S, ...) -> a new object with type S, a subtype of T
  __reduce__(...)
helper for pickle
  __reduce_ex__(...)
helper for pickle
  __setattr__(...)
x.__setattr__('name', value) <==> x.name = value
  __str__(x)
x.__str__() <==> str(x)

Class Variable Summary
str assertedColumnName = 'asserted'
str indexSuffix = 'Index'

Method Details

createSQL(self)

Generates a CREATE TABLE statement which creates a SQL table used for persisting assertions associated with this partition

flushInsertions(self, db)

Adds the pending identifiers / values and assertions (using executemany for maximum efficiency), and resets the queue.

foreignKeySQL(self, slot)

Generates foreign key expression relating a particular quad term with the identifier hash

generateHashIntersections(self)

Generates the SQL JOINS (INNER and LEFT) used to intersect the identifier and value hashes with this partition. This relies on each parition setting up an ordered list of intersections (ordered with optimization in mind). For instance the ABOX partition would want to intersect on classes first (since this will have a lower cardinality than any other field) wherease the Literal Properties partition would want to intersect on datatypes first. The paritions and hashes are joined on the integer half-MD5-hash of the URI (or literal) as well as the 'Term Type'

generateWhereClause(self, queryPattern)

Takes a query pattern (a list of quad terms - subject,predicate,object,context) and generates a SQL WHERE clauses which works in conjunction to the intersections to filter the result set by partial matching (by REGEX), full matching (by integer half-hash), and term types. For maximally efficient SELECT queries

insertRelations(self, quadSlots)

Takes a list of QuadSlot objects and queues the new identifiers / values to insert and the assertions as well (so they can be added in a batch for maximum efficiency)

insertRelationsSQLCMD(self)

Generates a SQL command with parameter references (%s) in order to facilitate efficient batch insertion of multiple assertions by Python DB implementations (such as MySQLdb)

selectContextFields(self, first)

Generates a list of column aliases for the SELECT SQL command used in order to fetch contexts from each partition

selectFields(self, first=False)

Returns a list of column aliases for the SELECT SQL command used to fetch quads from a partition

Class Variable Details

assertedColumnName

Type:
str
Value:
'asserted'

indexSuffix

Type:
str
Value:
'Index'

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