com.aspc.DBObj.Internal

Class DBObjectSearchPlan

java.lang.Object

com.aspc.DBObj.Internal.SearchPlan

com.aspc.DBObj.Internal.DBObjectSearchPlan

Direct Known Subclasses:

DBObjectSearchPlanV8

public abstract class DBObjectSearchPlan
extends SearchPlan

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	MAX_JOINS maximum number of tables to JOIN
static java.lang.String	RESOLUTION_ARCHIVE_CACHE The search was resolved by using archive cache.
static java.lang.String	RESOLUTION_DB_SEARCH The query was resolved by doing a DB scan.
static java.lang.String	RESOLUTION_FIELD_CACHE The query was handled by the field cache
static java.lang.String	RESOLUTION_FIELD_CACHE_IN The query was handled by the field cache
static java.lang.String	RESOLUTION_FULL_SEARCH The query was resolved by doing a full scan.
static java.lang.String	RESOLUTION_LINKAGE_CACHE the query was resolved by using linkage cache
static java.lang.String	RESOLUTION_LOAD_CACHE_IN The query was handled by the load cache
static java.lang.String	RESOLUTION_REVERSED The query was resolved by reversing the clause.
static java.lang.String	RESOLUTION_SPLIT_SEARCH The query was resolved by doing a SPLIT scan.

Fields inherited from class com.aspc.DBObj.Internal.SearchPlan

ALWAYS_LOAD_FIELD_CACHE_LIMIT, DEFAULT_TIMEOUT, maxFullListInsteadOfAffirmativeRestriction, maxFullRecordScan, query, RESOLUTION_KNOWN_TO_FAIL, RESOLUTION_UNKOWN

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method and Description
abstract void	addTranslateMap(java.util.Map<java.lang.String,TranslateClause> translateMap) Add the list of items
abstract java.lang.String[]	listSqlUsed() List the SQL statements used.
abstract PossibleRowsHolder	tryKeyWord() key word searches.
abstract PossibleRowsHolder	tryReverseSearch(DBClause usedClause, long currentLoadRows) Try to resolve the search by reversing the clauses.
abstract PossibleRowsHolder	trySplitOR() Split up OR clauses.
abstract PossibleRowsHolder	trySplitSearch() deal with OR clauses
abstract boolean	useClauseInsteadOfFullScan(long estimatedClauseRows) only do this search if we are going to limit loading of records.
abstract boolean	useFullSearch() Should we try the full search option ?
abstract boolean	useLinkageCache() Should we use linkageCache for this search ?

Methods inherited from class com.aspc.DBObj.Internal.SearchPlan

addClauseUsed, archiveSearch, checkThirdPhase, checkTimeout, cleanCriteria, doLayerSearch, getBottomLayer, getCriteria, getDataBase, getEstimatedDatabaseRows, getEstimatedMatchRows, getEstimatedMatchRows, getFirstClausedUsed, getMaxFullListInsteadOfAffirmativeRestriction, getMaxFullRecordScan, getMaximumRequiredRows, getQuery, getResolution, getSecondClausedUsed, getStartTime, getThirdClausedUsed, getTopLayer, isLayerExcluded, setForcePhaseThree, setMasterPlan, setMaxFullListInsteadOfAffirmativeRestriction, setMaxFullRecordScan, setMaximumRequiredRows, setResolution, tryPlanCache, useCache, willSearchFail

Methods inherited from class java.lang.Object

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

Field Detail

MAX_JOINS

public static final int MAX_JOINS

maximum number of tables to JOIN

See Also:

Constant Field Values

RESOLUTION_REVERSED

public static final java.lang.String RESOLUTION_REVERSED

The query was resolved by reversing the clause.

See Also:

Constant Field Values

RESOLUTION_FULL_SEARCH

public static final java.lang.String RESOLUTION_FULL_SEARCH

The query was resolved by doing a full scan.

See Also:

Constant Field Values

RESOLUTION_LINKAGE_CACHE

public static final java.lang.String RESOLUTION_LINKAGE_CACHE

the query was resolved by using linkage cache

See Also:

Constant Field Values

RESOLUTION_DB_SEARCH

public static final java.lang.String RESOLUTION_DB_SEARCH

The query was resolved by doing a DB scan.

See Also:

Constant Field Values

RESOLUTION_SPLIT_SEARCH

public static final java.lang.String RESOLUTION_SPLIT_SEARCH

The query was resolved by doing a SPLIT scan.

See Also:

Constant Field Values

RESOLUTION_FIELD_CACHE

public static final java.lang.String RESOLUTION_FIELD_CACHE

The query was handled by the field cache

See Also:

Constant Field Values

RESOLUTION_FIELD_CACHE_IN

public static final java.lang.String RESOLUTION_FIELD_CACHE_IN

The query was handled by the field cache

See Also:

Constant Field Values

RESOLUTION_LOAD_CACHE_IN

public static final java.lang.String RESOLUTION_LOAD_CACHE_IN

The query was handled by the load cache

See Also:

Constant Field Values

RESOLUTION_ARCHIVE_CACHE

public static final java.lang.String RESOLUTION_ARCHIVE_CACHE

The search was resolved by using archive cache.

See Also:

Constant Field Values

Constructor Detail

DBObjectSearchPlan

public DBObjectSearchPlan(@Nonnull
                          DBQuery query)

Creates a new Search plan

Parameters:

query - The query

Method Detail

addTranslateMap

public abstract void addTranslateMap(java.util.Map<java.lang.String,TranslateClause> translateMap)

Add the list of items

Parameters:

translateMap - the map of alias

listSqlUsed

public abstract java.lang.String[] listSqlUsed()

List the SQL statements used.

Returns:

the list of SQL statements

tryReverseSearch

public abstract PossibleRowsHolder tryReverseSearch(DBClause usedClause,
                                                    long currentLoadRows)
                                             throws java.lang.Exception

Try to resolve the search by reversing the clauses.

  SELECT *
  FROM Dilution
  WHERE instrument.ric like 'A%'
           | |
            V
   Step 1
   -------
   SELECT id
   FROM Asset
   WHERE ric like 'A%'

  Step 2
  -------
  SELECT *
  FROM Dilution
  WHERE instrument IS IN ( 1@10~10 ....)

 

Parameters:

usedClause - the clause has been used.

currentLoadRows - current estimate

Returns:

possible rows.

Throws:

java.lang.Exception - A serious problem

trySplitSearch

public abstract PossibleRowsHolder trySplitSearch()
                                           throws java.lang.Exception

deal with OR clauses

Returns:

the possible rows

Throws:

java.lang.Exception - a serious problem

trySplitOR

public abstract PossibleRowsHolder trySplitOR()
                                       throws java.lang.Exception

Split up OR clauses.

Returns:

The possible rows from the plan's special cache.

Throws:

java.lang.Exception - A serious problem

tryKeyWord

public abstract PossibleRowsHolder tryKeyWord()
                                       throws java.lang.Exception

key word searches.

Returns:

the key word

Throws:

java.lang.Exception - a serious problem.

useLinkageCache

public abstract boolean useLinkageCache()

Should we use linkageCache for this search ?

Returns:

TRUE if we should use linkage cache.

useFullSearch

public abstract boolean useFullSearch()
                               throws java.lang.Exception

Should we try the full search option ?

Returns:

TRUE if full search can be used.

Throws:

java.lang.Exception - A serious problem

useClauseInsteadOfFullScan

public abstract boolean useClauseInsteadOfFullScan(long estimatedClauseRows)

only do this search if we are going to limit loading of records. because some reverse searches can actually require more than the total number of rows for the base class to be loaded.

Parameters:

estimatedClauseRows - the estimate of the rows for this clause.

Returns:

true if we need to use the full scan