Uses of Interface
simpledb.query.Scan

Packages that use Scan

simpledb.index.query
simpledb.materialize
simpledb.multibuffer
simpledb.query

Uses of Scan in simpledb.index.query

Classes in simpledb.index.query that implement Scan

class	IndexJoinScan The scan class corresponding to the indexjoin relational algebra operator.
class	IndexSelectScan The scan class corresponding to the select relational algebra operator.

Methods in simpledb.index.query that return Scan

Scan	IndexSelectPlan.open() Creates a new indexselect scan for this query
Scan	IndexJoinPlan.open() Opens an indexjoin scan for this query

Constructors in simpledb.index.query with parameters of type Scan

IndexJoinScan(Scan s, Index idx, String joinfield, TableScan ts)
Creates an index join scan for the specified LHS scan and RHS index.

Uses of Scan in simpledb.materialize

Classes in simpledb.materialize that implement Scan

class	GroupByScan The Scan class for the groupby operator.
class	MergeJoinScan The Scan class for the mergejoin operator.
class	SortScan

Methods in simpledb.materialize that return Scan

Scan	SortPlan.open() This method is where most of the action is.
Scan	MergeJoinPlan.open() The method first sorts its two underlying scans on their join field.
Scan	MaterializePlan.open() This method loops through the underlying query, copying its output records into a temporary table.
Scan	GroupByPlan.open() This method opens a sort plan for the specified plan.

Methods in simpledb.materialize with parameters of type Scan

int	RecordComparator.compare(Scan s1, Scan s2) Compares the current records of the two specified scans.
void	MaxFn.processFirst(Scan s) Starts a new maximum to be the field value in the current record.
void	CountFn.processFirst(Scan s) Starts a new count.
void	AggregationFn.processFirst(Scan s) Uses the current record of the specified scan to be the first record in the group.
void	MaxFn.processNext(Scan s) Replaces the current maximum by the field value in the current record, if it is higher.
void	CountFn.processNext(Scan s) Since SimpleDB does not support null values, this method always increments the count, regardless of the field.
void	AggregationFn.processNext(Scan s) Uses the current record of the specified scan to be the next record in the group.

Constructors in simpledb.materialize with parameters of type Scan

GroupByScan(Scan s, Collection<String> groupfields, Collection<AggregationFn> aggfns)
Creates a groupby scan, given a grouped table scan.

GroupValue(Scan s, Collection<String> fields)
Creates a new group value, given the specified scan and list of fields.

MergeJoinScan(Scan s1, SortScan s2, String fldname1, String fldname2)
Creates a mergejoin scan for the two underlying sorted scans.

Uses of Scan in simpledb.multibuffer

Classes in simpledb.multibuffer that implement Scan

class	ChunkScan The class for the chunk operator.
class	MultiBufferProductScan The Scan class for the muti-buffer version of the product operator.

Methods in simpledb.multibuffer that return Scan

Scan	MultiBufferProductPlan.open() A scan for this query is created and returned, as follows.

Constructors in simpledb.multibuffer with parameters of type Scan

MultiBufferProductScan(Scan lhsscan, TableInfo ti, Transaction tx)
Creates the scan class for the product of the LHS scan and a table.

Uses of Scan in simpledb.query

Subinterfaces of Scan in simpledb.query

interface

UpdateScan The interface implemented by all updateable scans.

Classes in simpledb.query that implement Scan

class	ProductScan The scan class corresponding to the product relational algebra operator.
class	ProjectScan The scan class corresponding to the project relational algebra operator.
class	SelectScan The scan class corresponding to the select relational algebra operator.
class	TableScan The Scan class corresponding to a table.

Methods in simpledb.query that return Scan

Scan	TablePlan.open() Creates a table scan for this query.
Scan	SelectPlan.open() Creates a select scan for this query.
Scan	ProjectPlan.open() Creates a project scan for this query.
Scan	ProductPlan.open() Creates a product scan for this query.
Scan	Plan.open() Opens a scan corresponding to this plan.

Methods in simpledb.query with parameters of type Scan

Constant	FieldNameExpression.evaluate(Scan s) Evaluates the field by getting its value in the scan.
Constant	Expression.evaluate(Scan s) Evaluates the expression with respect to the current record of the specified scan.
Constant	ConstantExpression.evaluate(Scan s) Returns the constant, regardless of the scan.
boolean	Term.isSatisfied(Scan s) Returns true if both of the term's expressions evaluate to the same constant, with respect to the specified scan.
boolean	Predicate.isSatisfied(Scan s) Returns true if the predicate evaluates to true with respect to the specified scan.

Constructors in simpledb.query with parameters of type Scan

ProductScan(Scan s1, Scan s2)
Creates a product scan having the two underlying scans.

ProjectScan(Scan s, Collection<String> fieldlist)
Creates a project scan having the specified underlying scan and field list.

SelectScan(Scan s, Predicate pred)
Creates a select scan having the specified underlying scan and predicate.