Class ConglomerateDescriptor
java.lang.Object
org.apache.derby.iapi.sql.dictionary.TupleDescriptor
org.apache.derby.iapi.sql.dictionary.UniqueTupleDescriptor
org.apache.derby.iapi.sql.dictionary.ConglomerateDescriptor
- All Implemented Interfaces:
Dependable
,Provider
The ConglomerateDescriptor class is used to get information about
conglomerates for the purpose of optimization.
A ConglomerateDescriptor can map to a base table, an index
or a index backing a constraint. Multiple ConglomerateDescriptors
can map to a single underlying store conglomerate, such as when
multiple index definitions share a physical file.
NOTE: The language module does not have to know much about conglomerates
with this architecture. To get the cost of using a conglomerate, all it
has to do is pass the ConglomerateDescriptor to the access methods, along
with the predicate. What the access methods need from a
ConglomerateDescriptor remains to be seen.
- Version:
- 0.1
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate String[]
private long
private final boolean
private final boolean
private final IndexRowGenerator
private String
private final UUID
private final UUID
private final UUID
Fields inherited from interface org.apache.derby.catalog.Dependable
ACTIVATION, ALIAS, COLUMNS_IN_TABLE, COLUMNS_PERMISSION, CONGLOMERATE, CONSTRAINT, DEFAULT, FILE, HEAP, INDEX, PERM, PREPARED_STATEMENT, ROLE_GRANT, ROUTINE_PERMISSION, SCHEMA, SEQUENCE, STORED_PREPARED_STATEMENT, TABLE, TABLE_PERMISSION, TRIGGER, VIEW
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Constructor Summary
ConstructorsConstructorDescriptionConglomerateDescriptor
(DataDictionary dataDictionary, long conglomerateNumber, String name, boolean indexable, IndexRowGenerator indexRowGenerator, boolean forConstraint, UUID uuid, UUID tableID, UUID schemaID) Constructor for a conglomerate descriptor. -
Method Summary
Modifier and TypeMethodDescriptiondescribeSharedConglomerate
(ConglomerateDescriptor[] descriptors, boolean ignoreThis) This method searches the received array of conglom descriptors to find all descriptors that currently share a physical conglom with "this".drop
(LanguageConnectionContext lcc, TableDescriptor td) Drop this ConglomerateDescriptor when it represents an index.Get the provider's type.String[]
Get the column names for this conglomerate descriptor.Gets the name of the conglomerate.long
Gets the number for the conglomerate.Get an object which can be written to disk and which, when read from disk, will find or reconstruct this in-memory Dependable.Each descriptor must identify itself with its type; i.e index, check constraint whatever.Gets the index row generator for this conglomerate, null if the conglomerate is not an index.Get the provider's UUIDReturn the name of this Provider.Gets the UUID for the schema that the conglomerate belongs to.Gets the UUID for the table that the conglomerate belongs to.getUUID()
Gets the UUID String for the conglomerate.boolean
Tells whether the conglomerate is an index backing up a constraint.boolean
isIndex()
Tells whether the conglomerate can be used as an index.void
setColumnNames
(String[] columnNames) Set the column names for this conglomerate descriptor.void
setConglomerateName
(String newName) Set the name of the conglomerate.void
setConglomerateNumber
(long conglomerateNumber) Set the conglomerate number.toString()
Convert the conglomerate descriptor to a StringMethods inherited from class org.apache.derby.iapi.sql.dictionary.TupleDescriptor
getColumnDependableFinder, getDataDictionary, getDependableFinder, isPersistent, setDataDictionary
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
Methods inherited from interface org.apache.derby.catalog.Dependable
isPersistent
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Field Details
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conglomerateNumber
private long conglomerateNumber -
name
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columnNames
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indexable
private final boolean indexable -
forConstraint
private final boolean forConstraint -
indexRowGenerator
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uuid
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tableID
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schemaID
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Constructor Details
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ConglomerateDescriptor
ConglomerateDescriptor(DataDictionary dataDictionary, long conglomerateNumber, String name, boolean indexable, IndexRowGenerator indexRowGenerator, boolean forConstraint, UUID uuid, UUID tableID, UUID schemaID) Constructor for a conglomerate descriptor.- Parameters:
dataDictionary
- The data dictionary that this descriptor lives inconglomerateNumber
- The number for the conglomerate we're interested inname
- The name of the conglomerate, if anyindexable
- TRUE means the conglomerate is indexable, FALSE means it isn'tindexRowGenerator
- The descriptor of the index if it's not a heapforConstraint
- TRUE means the conglomerate is an index backing up a constraint, FALSE means it isn'tuuid
- UUID for this conglomeratetableID
- UUID for the table that this conglomerate belongs toschemaID
- UUID for the schema that this conglomerate belongs to
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Method Details
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getConglomerateNumber
public long getConglomerateNumber()Gets the number for the conglomerate.- Returns:
- A long identifier for the conglomerate
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setConglomerateNumber
public void setConglomerateNumber(long conglomerateNumber) Set the conglomerate number. This is useful when swapping conglomerates, like for bulkInsert.- Parameters:
conglomerateNumber
- The new conglomerate number.
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getUUID
Gets the UUID String for the conglomerate.- Specified by:
getUUID
in classUniqueTupleDescriptor
- Returns:
- The UUID String for the conglomerate
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getTableID
Gets the UUID for the table that the conglomerate belongs to.- Returns:
- The UUID String for the conglomerate
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getSchemaID
Gets the UUID for the schema that the conglomerate belongs to.- Returns:
- The UUID String for the schema that the conglomerate belongs to
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isIndex
public boolean isIndex()Tells whether the conglomerate can be used as an index.- Returns:
- TRUE if the conglomerate can be used as an index, FALSE if not
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isConstraint
public boolean isConstraint()Tells whether the conglomerate is an index backing up a constraint.- Returns:
- TRUE if the conglomerate is an index backing up a constraint, FALSE if not
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getConglomerateName
Gets the name of the conglomerate. For heaps, this is null. For indexes, it is the index name.- Returns:
- The name of the conglomerate, null if it's the heap for a table.
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setConglomerateName
Set the name of the conglomerate. Used only by rename index.- Parameters:
newName
- The new name of the conglomerate.
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getIndexDescriptor
Gets the index row generator for this conglomerate, null if the conglomerate is not an index.- Returns:
- The index descriptor for this conglomerate, if any.
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setColumnNames
Set the column names for this conglomerate descriptor. This is useful for tracing the optimizer.- Parameters:
columnNames
- 0-based array of column names.
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getColumnNames
Get the column names for this conglomerate descriptor. This is useful for tracing the optimizer.- Returns:
- the column names for the conglomerate descriptor.
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getDependableFinder
Description copied from interface:Dependable
Get an object which can be written to disk and which, when read from disk, will find or reconstruct this in-memory Dependable.- Specified by:
getDependableFinder
in interfaceDependable
- Returns:
- the stored form of this provider
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getObjectName
Return the name of this Provider. (Useful for errors.)- Specified by:
getObjectName
in interfaceDependable
- Returns:
- String The name of this provider.
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getObjectID
Get the provider's UUID- Specified by:
getObjectID
in interfaceDependable
- Returns:
- The provider's UUID
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getClassType
Get the provider's type.- Specified by:
getClassType
in interfaceDependable
- Returns:
- char The provider's type.
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toString
Convert the conglomerate descriptor to a String -
getDescriptorType
Description copied from class:TupleDescriptor
Each descriptor must identify itself with its type; i.e index, check constraint whatever.- Overrides:
getDescriptorType
in classTupleDescriptor
- See Also:
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getDescriptorName
- Overrides:
getDescriptorName
in classTupleDescriptor
- See Also:
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drop
public ConglomerateDescriptor drop(LanguageConnectionContext lcc, TableDescriptor td) throws StandardException Drop this ConglomerateDescriptor when it represents an index. If this is the last desciptor for a physical index then the physical index (conglomerate) and its descriptor will be dropped.- Parameters:
lcc
- Connection context to use for droppingtd
- TableDescriptor for the table to which this conglomerate belongs- Returns:
- If the conglomerate described by this descriptor is an index conglomerate that is shared by multiple constraints/indexes, then we may have to create a new conglomerate to satisfy the constraints/indexes which remain after we drop the existing conglomerate. If that's needed then we'll return a conglomerate descriptor which describes what the new conglomerate must look like. It is then up to the caller of this method to create a new corresponding conglomerate. We don't create the index here because depending on who called us, it might not make sense to create it--esp. if we get here because of a DROP TABLE.
- Throws:
StandardException
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