I | Understanding DB2: Learning Visually with Examples (2nd Edition)

identity column: A column that provides a way for DB2 to automatically generate a numeric value for each row inserted into the table. Identity columns are defined with the AS IDENTITY clause. A table can only have one identity column.

idle agent: A database agent that currently does not have a database connection or an application attachment.

implicit privilege

(1) A privilege that accompanies the ownership of an object, such as the privilege to drop a synonym one owns or the holding of an authority, such as the privilege of SYSADM authority to terminate any utility job.

(2) A privilege that is granted to a user who has the privilege to execute a package on data objects used within the package that does not require granted explicit privileges.

import

(1) To copy data from an external file, using formats such as PC/IXF, DEL, WSF, or ASC, into database tables.

(2) In the Information Catalog Center, to read the contents of a tag language file to initially populate the information catalog, change the information catalog contents, or copy the contents of another information catalog.

See also [export]

import utility: A transactional utility that inserts user-supplied record data into a table.

incremental backup: A copy of all database data that has changed since the most recent successful full backup operation. This is also known as a cumulative backup image, because a series of incremental backups taken over time will each have the contents of the previous incremental backup image. The predecessor of an incremental backup image is always the most recent successful full backup of the same object.

index: A set of pointers that are logically ordered by the values of a key. Indexes provide quick access to data and can enforce uniqueness on the rows in a table. When you request an index, the database manager builds the structure and maintains it automatically. The database manager uses indexes to improve performance and ensure uniqueness.

index key: The set of columns in a table that determines the order of index entries.

individual privilege: A privilege that is granted to a single data object.

indoubt: The status of a unit of recovery. If the database manager fails after it finishes its phase 1 commit processing and before it starts phase 2, only the commit coordinator knows if an individual unit of recovery is to be committed or rolled back. At an emergency restart, if the database manager lacks the information that it needs to make this decision, the status of the unit of recovery is indoubt until the database manager obtains this information from the coordinator. More than one unit of recovery can be indoubt at restart.

indoubt resolution: The process of resolving the status of an indoubt logical unit of work to either the committed or the roll back state.

indoubt transaction: A transaction in which one phase of a two-phase commit completes successfully but the system fails before a subsequent phase can complete.

inflight: A status of a unit of recovery.

information catalog: A collection of metadata, managed by the Information Catalog Center, containing descriptive data (business metadata) that helps users identify and locate data and information available to them in the organization. An information catalog also contains some technical metadata.

informational configuration parameter: A type of configuration parameter that holds information that cannot be modified.

inheritance: The passing of class resources or attributes from a parent class downstream in the class hierarchy to a child class.

initialization fullselect: The first fullselect in a recursive common table expression that gets the direct children of the initial value from the source table.

inner join: A join method in which a column that is not common to all of the tables being joined is dropped from the result table.

inoperative package: A package that cannot be used because a function it depends on has been dropped. Such a package must be explicitly rebound.

inoperative trigger: A trigger that depends on an object that has been dropped or made inoperative or on a privilege that has been revoked.

inoperative view

(1) A view no longer usable because the SELECT privilege on a table or view that the view is dependent on is revoked from the definer of the view.

(2) An object on which the view definition is dependent was dropped (or possibly made inoperative in the case of another view).

insert rule: A condition enforced by the database manager that must be met before a row can be inserted into a table.

insert trigger: A trigger that is defined with the triggering SQL operation INSERT.

instance

(1) A logical DB2 extender server environment. You can have several instances of DB2 extenders server on the same workstation, but only one instance for each DB2 instance.

(2)

See also [database manager instance]

instance-owning partition: The first database-partition server that is installed in a partitioned database environment.

interactive SQL: A set of SQL statements that is provided through an interface such as the Command Center or Command Line Processor. These statements are processed as dynamic SQL statements. For example, an interactive SELECT statement can be processed dynamically using the DECLARE CURSOR, PREPARE, DESCRIBE, OPEN, FETCH, and CLOSE statements.

inter-partition parallelism: A single database operation (for example, index creation) that is executed in parallel across the partitions of a partitioned database.

inter-process communication (IPC): A mechanism of an operating system that allows processes to communicate with each other within the same computer or over a network.

inter-query parallelism: The ability of multiple applications to query a database at the same time. Each query executes independently of the others, but DB2 runs all of them at the same time.

intra-partition parallelism: The subdivision of a single database operation (for example, index creation) into multiple parts, which are then executed in parallel within a single database partition.

intra-query parallelism: The ability to process parts of a single query at the same time using either intra-partition parallelism, inter-partition parallelism, or both.

invalid package: A package that depends on an object that has been dropped.

I/O parallelism: See [parallelism]

IP address: A 4-byte value that uniquely identifies a TCP/IP host.

isolation level

(1) A security feature that determines how data is locked from other processes while it is being accessed.

(2) An attribute that defines the degree to which an application process is isolated from other concurrently executing application processes.