simpledb

Class Catalog

java.lang.Object

simpledb.Catalog

public class Catalog
extends java.lang.Object

The Catalog keeps track of all available tables in the database and their associated schemas. For now, this is a stub catalog that must be populated with tables by a user program before it can be used -- eventually, this should be converted to a catalog that reads a catalog table from disk.

Constructor Summary

Constructors

Constructor and Description
Catalog() Constructor.

Method Summary

Modifier and Type	Method and Description
void	addTable(DbFile file) Add a new table to the catalog.
void	addTable(DbFile file, java.lang.String name)
void	addTable(DbFile file, java.lang.String name, java.lang.String pkeyField) Add a new table to the catalog.
void	clear() Delete all tables from the catalog
DbFile	getDatabaseFile(int tableid) Returns the DbFile that can be used to read the contents of the specified table.
java.lang.String	getPrimaryKey(int tableid)
int	getTableId(java.lang.String name) Return the id of the table with a specified name,
java.lang.String	getTableName(int id)
TupleDesc	getTupleDesc(int tableid) Returns the tuple descriptor (schema) of the specified table
void	loadSchema(java.lang.String catalogFile) Reads the schema from a file and creates the appropriate tables in the database.
java.util.Iterator<java.lang.Integer>	tableIdIterator()

Methods inherited from class java.lang.Object

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

Constructor Detail

Catalog

public Catalog()

Constructor. Creates a new, empty catalog.

Method Detail

addTable

public void addTable(DbFile file,
                     java.lang.String name,
                     java.lang.String pkeyField)

Add a new table to the catalog. This table's contents are stored in the specified DbFile.

Parameters:

file - the contents of the table to add; file.getId() is the identfier of this file/tupledesc param for the calls getTupleDesc and getFile

name - the name of the table -- may be an empty string. May not be null. If a name conflict exists, use the last table to be added as the table for a given name.

pkeyField - the name of the primary key field

addTable

public void addTable(DbFile file,
                     java.lang.String name)

addTable

public void addTable(DbFile file)

Add a new table to the catalog. This table has tuples formatted using the specified TupleDesc and its contents are stored in the specified DbFile.

Parameters:

file - the contents of the table to add; file.getId() is the identfier of this file/tupledesc param for the calls getTupleDesc and getFile

getTableId

public int getTableId(java.lang.String name)
               throws java.util.NoSuchElementException

Return the id of the table with a specified name,

Throws:

java.util.NoSuchElementException - if the table doesn't exist

getTupleDesc

public TupleDesc getTupleDesc(int tableid)
                       throws java.util.NoSuchElementException

Returns the tuple descriptor (schema) of the specified table

Parameters:

tableid - The id of the table, as specified by the DbFile.getId() function passed to addTable

Throws:

java.util.NoSuchElementException - if the table doesn't exist

getDatabaseFile

public DbFile getDatabaseFile(int tableid)
                       throws java.util.NoSuchElementException

Returns the DbFile that can be used to read the contents of the specified table.

Parameters:

tableid - The id of the table, as specified by the DbFile.getId() function passed to addTable

Throws:

java.util.NoSuchElementException

getPrimaryKey

public java.lang.String getPrimaryKey(int tableid)

tableIdIterator

public java.util.Iterator<java.lang.Integer> tableIdIterator()

getTableName

public java.lang.String getTableName(int id)

clear

public void clear()

Delete all tables from the catalog

loadSchema

public void loadSchema(java.lang.String catalogFile)

Reads the schema from a file and creates the appropriate tables in the database.

Parameters:

catalogFile -