Chapter6 Flashcards
is the main database object
Tables
is defined with columns and stores rows of data
Table
are used to hold temporary data specific to a transaction or session
Temporary tables
- these types of columns do not consume storage space on disk
- database derives values in virtual columns from normal columns
Virtual columns
- is a customized representation of data from one or more tables and/or view
- are queries stored in the database that select data from one or more tables
View
is a way to generate continuous numbers
Sequence
is an alias for any table, view, sequence, or other accessible database object
Synonym
are objects used to summarize and replicate data
Materialized view
is a logical structure to define the relationship between columns in a table
Dimension
is a method of storing data from related tables at a common physical
Cluster
are created with user-defined datatypes.
Object table
is a collection of related database objects grouped together
schema
is a schema object that enables you to access an object from a different database.
Database links
is a stored PL/SQL program that gets executed when a specified condition occurs on the table.
Tiggers
any java stuff
java objects
- procedure
- function
- packages
PL/SQL programs
is a PL/SQL programmatic construct
procedure
like procedure but it returns a value
function
it is a grouping of related PL/SQL
package
- variable length strings (backward compatibility)
- discourage in Oracle
- 2GBYTES
long
variable length binary string
2Kbytes
raw
- variable length binary strings
- 2GBYTES
long raw
- is one of the Large Object datatypes provided to store variable length character data
- Character large object
CLOB
is one of the Large Object datatypes and stores variable-length Unicode character data
NCLOB
- represents all non-Oracle numeric datatypes(floats, decimal, integer)
- can store both fixed-point and floating-point number
Number
datatype represents a 32-bit floating-point number
Binary_Float
datatype represents a 64-bit floating-point number
BINARY_DOUBLE
it a subtype of Number ans is internally represented as Number
FLOAT
it stores date and time information
date
- stores date and time information with fractional seconds precision
- fractional_seconds_precision
timestamp
Equivalent to Number (p,0)
INTEGER
NCHAR with max 4K bytes, no blank-padded
NVARCHAR2
Base-64 string unique row address
ROWID
Base-64 string index-organized table
UROWID
Binary large object
BLOB
locator to a large binary file outside database
BFILE
the special characters allowed in identifier name are the $, _ , #
also do not use quotation marks on identifier name
table and column names are ____
- can be up to 30 characters long
identifiers
the existing data in the table is validated to verify that it conforms to the constraint.
Enable validate
This does not validate the existing data but enables the constraint for future constraint checking
Enable Novalidate
The constraint id disable but the constraint is kept valid
Disable Validate
the constraint is disabled and no checks are done on or future or existing data
Disable novalidate
index in the form of a balanced tree
B-tree index
- each bit position represents a row that may or may not contain the indexed value
- best for low-cardinality column
bitmap index
is a structure associated with tables used to speed up the queries
index
