com.aspc.DBObj.Internal

Class SearchPlan

java.lang.Object

com.aspc.DBObj.Internal.SearchPlan

Direct Known Subclasses:

DBObjectSearchPlan, SimpleCassandraSearchPlan, SimpleSearchPlan, SimpleSearchPlan, TestSelectSearchPlan.NoFindPlan

public abstract class SearchPlan
extends java.lang.Object

Analyze the clauses to create the best method of search. THREAD MODE: SINGLE-THREADED one search plan per query

Since:

2 June 2002

Author:

Nigel Leck

Field Summary

Fields

Modifier and Type	Field and Description
static int	ALWAYS_LOAD_FIELD_CACHE_LIMIT If the estimate rows is less than this value just load it anyway
static long	DEFAULT_TIMEOUT The default time out period for a query
protected int	maxFullListInsteadOfAffirmativeRestriction max full list
protected long	maxFullRecordScan max full scan
protected DBQuery	query the query
static java.lang.String	RESOLUTION_KNOWN_TO_FAIL This query will fail we should not try
static java.lang.String	RESOLUTION_UNKOWN The resolution is Unknown

Constructor Summary

Constructors

Constructor and Description
SearchPlan(DBQuery query) Creates a new Search plan

Method Summary

Modifier and Type	Method and Description
void	addClauseUsed(DBPathClause bestClause) add the clause that was used
abstract boolean	archiveSearch(LayerSearchResult lsr) do an archive search
boolean	checkThirdPhase(PossibleRowsHolder rows) check third phase
long	checkTimeout() Check the query timeout.
static DBClause	cleanCriteria(DBQuery query, DBClause clause) clean a criteria
abstract void	doLayerSearch(LayerSearchResult lsr)
VirtualDB	getBottomLayer() The bottom most possible layer
DBCriteria	getCriteria() Short hand to the query's criteria
VirtualDB	getDataBase() The virtual database for this plan
long	getEstimatedDatabaseRows() The number of rows in the database for this class.
long	getEstimatedMatchRows(DBCriteria criteria)
long	getEstimatedMatchRows(DBPathClause pc) The estimated number of rows that will be returned by this clause.
DBPathClause	getFirstClausedUsed() what clause was used ?
int	getMaxFullListInsteadOfAffirmativeRestriction() The maximum size of the full table list that will be used for a in-memory table scan instead of an affirmative restriction database search
long	getMaxFullRecordScan() the max full record to scan
int	getMaximumRequiredRows() get the maximum number of rows to fetch.
DBQuery	getQuery() The actual query for this plan
java.lang.String	getResolution() What was the resolution ?
DBPathClause	getSecondClausedUsed() The second clause was used ?
long	getStartTime() When did the query start ?
DBPathClause	getThirdClausedUsed() The third clause was used ?
VirtualDB	getTopLayer() The top most possible layer
boolean	isLayerExcluded(int layerId) Is the search excluded from this layer ?
void	setForcePhaseThree(boolean flag) force phase three
SearchPlan	setMasterPlan(SearchPlan masterPlan) Set the master plan
void	setMaxFullListInsteadOfAffirmativeRestriction(int max) set the maximum size of the full table list that will be used for a in-memory table scan instead of an affirmative restriction database search
void	setMaxFullRecordScan(long maxRows) set max full record scan
void	setMaximumRequiredRows(int rows) set the maximum number of rows to fetch.
void	setResolution(java.lang.String type) How did we find the records ?
PossibleRowsHolder	tryPlanCache() CAN YOU HANDLE THIS QUERY ? If so return the possible rows here.
boolean	useCache() Should we use the cache for this query.
boolean	willSearchFail() Will this search fail ?

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

ALWAYS_LOAD_FIELD_CACHE_LIMIT

public static final int ALWAYS_LOAD_FIELD_CACHE_LIMIT

If the estimate rows is less than this value just load it anyway

See Also:

Constant Field Values

RESOLUTION_UNKOWN

public static final java.lang.String RESOLUTION_UNKOWN

The resolution is Unknown

See Also:

Constant Field Values

RESOLUTION_KNOWN_TO_FAIL

public static final java.lang.String RESOLUTION_KNOWN_TO_FAIL

This query will fail we should not try

See Also:

Constant Field Values

DEFAULT_TIMEOUT

public static final long DEFAULT_TIMEOUT

The default time out period for a query

maxFullListInsteadOfAffirmativeRestriction

protected int maxFullListInsteadOfAffirmativeRestriction

max full list

query

protected final DBQuery query

the query

maxFullRecordScan

protected long maxFullRecordScan

max full scan

Constructor Detail

SearchPlan

public SearchPlan(@Nonnull
                  DBQuery query)

Creates a new Search plan

Parameters:

query - The query

Method Detail

setMasterPlan

public SearchPlan setMasterPlan(SearchPlan masterPlan)

Set the master plan

Parameters:

masterPlan - the master plan

Returns:

the old master plan

cleanCriteria

public static DBClause cleanCriteria(DBQuery query,
                                     DBClause clause)

clean a criteria

Parameters:

query - the query

clause - the clause to check

Returns:

the cleaned clause.

doLayerSearch

public abstract void doLayerSearch(LayerSearchResult lsr)
                            throws java.lang.Exception

Parameters:

lsr - the result

Throws:

java.lang.Exception - a serious problem

archiveSearch

public abstract boolean archiveSearch(LayerSearchResult lsr)
                               throws java.lang.Exception

do an archive search

Parameters:

lsr - the result

Returns:

true if we hit the database

Throws:

java.lang.Exception - a serious problem

useCache

@CheckReturnValue
public boolean useCache()

Should we use the cache for this query. Do you know that we will not find it so that a cache search is slow ?

Returns:

true if we can use cache.

getStartTime

@CheckReturnValue
public long getStartTime()

When did the query start ?

Returns:

The start time in milliseconds.

getBottomLayer

@CheckReturnValue
 @Nonnull
public VirtualDB getBottomLayer()

The bottom most possible layer

Returns:

The layer.

checkTimeout

public long checkTimeout()
                  throws QueryTimeoutException

Check the query timeout.

Returns:

The remaining time in milliseconds.

Throws:

QueryTimeoutException - The query has run longer than the maximum query time.

tryPlanCache

@CheckReturnValue
 @Nullable
public PossibleRowsHolder tryPlanCache()
                                                             throws java.lang.Exception

CAN YOU HANDLE THIS QUERY ? If so return the possible rows here.

The possible rows need to be the super set of rows. The actual filtering will happen in DBResult.

Returns:

The possible rows from the plan's special cache.

Throws:

java.lang.Exception - A serious problem

setResolution

public void setResolution(java.lang.String type)

How did we find the records ?

Parameters:

type - The resolution

getResolution

@CheckReturnValue
public java.lang.String getResolution()

What was the resolution ?

Returns:

The description.

setMaximumRequiredRows

public void setMaximumRequiredRows(int rows)

set the maximum number of rows to fetch.

Parameters:

rows - the max rows.

getMaximumRequiredRows

@CheckReturnValue
public int getMaximumRequiredRows()

get the maximum number of rows to fetch.

Returns:

the max rows.

getQuery

@CheckReturnValue
public final DBQuery getQuery()

The actual query for this plan

Returns:

The query for this plan.

getCriteria

@CheckReturnValue
public final DBCriteria getCriteria()

Short hand to the query's criteria

Returns:

The criteria

getDataBase

@CheckReturnValue
public final VirtualDB getDataBase()

The virtual database for this plan

Returns:

The layer.

willSearchFail

@CheckReturnValue
public boolean willSearchFail()

Will this search fail ?

Returns:

True if the search is known to fail.

getTopLayer

@CheckReturnValue
 @Nonnull
public VirtualDB getTopLayer()

The top most possible layer

Returns:

The layer.

isLayerExcluded

@CheckReturnValue
public boolean isLayerExcluded(int layerId)

Is the search excluded from this layer ?

Parameters:

layerId - The layer Id

Returns:

true if excluded.

getFirstClausedUsed

@CheckReturnValue
 @Nullable
public DBPathClause getFirstClausedUsed()

what clause was used ?

Returns:

the clause

getSecondClausedUsed

@CheckReturnValue
 @Nullable
public DBPathClause getSecondClausedUsed()

The second clause was used ?

Returns:

the clause

getThirdClausedUsed

@CheckReturnValue
 @Nullable
public DBPathClause getThirdClausedUsed()

The third clause was used ?

Returns:

the clause

getMaxFullRecordScan

@CheckReturnValue
 @Nonnegative
public long getMaxFullRecordScan()

the max full record to scan

Returns:

the max rows

setMaxFullRecordScan

public void setMaxFullRecordScan(long maxRows)

set max full record scan

Parameters:

maxRows - the max rows

addClauseUsed

public void addClauseUsed(@Nullable
                          DBPathClause bestClause)

add the clause that was used

Parameters:

bestClause - the clause used

setForcePhaseThree

public void setForcePhaseThree(boolean flag)

force phase three

Parameters:

flag - true to turn on.

checkThirdPhase

@CheckReturnValue
public boolean checkThirdPhase(@Nonnull
                                                 PossibleRowsHolder rows)

check third phase

Parameters:

rows - the rows

Returns:

true if we should check.

getEstimatedDatabaseRows

@CheckReturnValue
 @Nonnegative
public long getEstimatedDatabaseRows()

The number of rows in the database for this class.

Returns:

The number of rows.

getEstimatedMatchRows

@CheckReturnValue
 @Nonnegative
public long getEstimatedMatchRows(@Nonnull
                                                                  DBPathClause pc)

The estimated number of rows that will be returned by this clause. If we can only pick one clause then pick the one with the least number of rows.

Parameters:

pc - The clause to estimate

Returns:

The number of rows.

getEstimatedMatchRows

@CheckReturnValue
 @Nonnegative
public long getEstimatedMatchRows(@Nonnull
                                                                  DBCriteria criteria)

getMaxFullListInsteadOfAffirmativeRestriction

@CheckReturnValue
 @Nonnegative
public int getMaxFullListInsteadOfAffirmativeRestriction()

The maximum size of the full table list that will be used for a in-memory table scan instead of an affirmative restriction database search

Returns:

The number of rows.

setMaxFullListInsteadOfAffirmativeRestriction

public void setMaxFullListInsteadOfAffirmativeRestriction(int max)

set the maximum size of the full table list that will be used for a in-memory table scan instead of an affirmative restriction database search

Parameters:

max - the maximum rows.