HP NonStop SQL/MX Glossary Abstract This glossary describes terms that are specific to HP NonStop™ SQL/MX. Product Version NonStop SQL/MX Releases 2.0 and 2.1 Supported Release Version Updates (RVUs) This publication supports G06.23 and all subsequent G-series RVUs until otherwise indicated by its replacement publication.
Document History Part Number Product Version Published 520363-001 NonStop SQL/MX Release 1.5 November 2001 524766-001 NonStop SQL/MX Release 1.5 August 2002 523731-001 NonStop SQL/MX Release 1.8 December 2002 523732-001 NonStop SQL/MX Release 2.0 April 2004 523732-002 NonStop SQL/MX Releases 2.0 and 2.
HP NonStop SQL/MX Glossary Glossary What’s New in This Manual iii Manual Information iii New and Changed Information iv About This Manual v Audience v Related Documentation v Notation Conventions viii Glossary A B C D E F G H I J K L M N O P Q R S T U V Glossary-1 Glossary-3 Glossary-3 Glossary-7 Glossary-10 Glossary-13 Glossary-13 Glossary-14 Glossary-15 Glossary-16 Glossary-17 Glossary-17 Glossary-19 Glossary-22 Glossary-24 Glossary-26 Glossary-28 Glossary-28 Glossary-31 Glossary-37 Glossary-39 Glos
Glossary (continued) Contents Glossary (continued) W Glossary-40 HP NonStop SQL/MX Glossary—523732-002 ii
What’s New in This Manual Manual Information HP NonStop SQL/MX Glossary Abstract This glossary describes terms that are specific to HP NonStop™ SQL/MX. Product Version NonStop SQL/MX Releases 2.0 and 2.1 Supported Release Version Updates (RVUs) This publication supports G06.23 and all subsequent G-series RVUs until otherwise indicated by its replacement publication. Part Number Published 523732-002 June 2005 Document History Part Number Product Version Published 520363-001 NonStop SQL/MX Release 1.
New and Changed Information What’s New in This Manual New and Changed Information These terms have been added or changed for this release: alias mapping MPALIAS table SQL/MP alias ANSI external name OLT optimization SQL/MX catalog manager ANSI internal name SQL-92 user metadata tables bulk move SQL:1999 mixed-workload environment SQL:2003 The technical content of this publication has been updated and reflects the state of the product at the G06.26 RVU.
About This Manual This manual lists terms relevant to NonStop SQL/MX and related subsystems. Audience This manual was written for SQL/MX database administrators and programmers who are using the SQL/MX conversational or programmatic interface.
Related Documentation About This Manual Specialized Guides SQL/MX Installation and Management Guide Describes how to plan for, install, create, and manage an SQL/MX database. Explains how to use installation and management commands and utilities. SQL/MX Query Guide Describes how to understand query execution plans and write optimal queries for an SQL/MX database. SQL/MX Data Mining Guide Describes the SQL/MX data structures and operations to carry out the knowledge-discovery process.
Related Documentation About This Manual Technical Library (NTL). For more information about downloading online help, see the SQL/MX Installation and Management Guide. These manuals are part of the SQL/MP library of manuals and are essential references for information about SQL/MP Data Definition Language (DDL) and SQL/MP installation and management: Related SQL/MP Manuals SQL/MP Reference Manual Describes the SQL/MP language elements, expressions, predicates, functions, and statements.
Notation Conventions About This Manual Programming Manuals Introductory Guides SQL/MX Comparison Guide for SQL/MP Users SQL/MX Quick Start SQL/MX Programming Manual for C and COBOL SQL/MX Programming Manual for Java Reference Manuals SQL/MX Reference Manual SQL/MX Messages Manual SQL/MX Glossary SQL/MX Connectivity Service Administrative Command Reference DataLoader/MX Reference Manual Specialized Guides SQL/MX Installation and Management Guide NSM/web Installation Guide SQL/MX Guide to Stor
General Syntax Notation About This Manual This requirement is described under Backup DAM Volumes and Physical Disk Drives on page 3-2. General Syntax Notation This list summarizes the notation conventions for syntax presentation in this manual. UPPERCASE LETTERS. Uppercase letters indicate keywords and reserved words. Type these items exactly as shown. Items not enclosed in brackets are required. For example: MAXATTACH lowercase italic letters.
Change Bar Notation About This Manual HP NonStop SQL/MX Glossary—523732-002 x
Glossary A B C D E F G H I J K M N O P Q R S T U V W L A 3GL. Third-generation language. A high-level programming language such as C or Java. 4GL. A nonprocedural, high-level language, such as structured query language (SQL), that is used for database management systems. aborted transaction. A transaction that was backed out (undone). See also transaction access option. A DML statement option that affects the consistency of data accessed by the statement execution.
ANSI internal name Glossary SQL/MX, they are given external names. ANSI external names must conform to ANSI naming conventions. See also ANSI internal name. ANSI internal name. A name defined when objects are stored in the metadata. ANSI SQL objects have both external and internal names. When objects are created or altered in SQL/MX, they are given external names. However, when the same objects are stored in the metadata, they are stored by their internal names.
automatic SQL recompilation Glossary automatic SQL recompilation. The SQL recompilation in memory of a program or SQL statement invoked by the SQL executor at run time. Automatic recompilation occurs, for example, when an SQL object definition has changed since the program’s last explicit SQL compilation. B backout. To restore a file, database, or system to its previous condition by removing changes.
CAST specification Glossary CAST specification. A specification or function that converts data to the data type you specify. catalog. A named logical object that contains descriptions of a set of schemas. catalog reference. An indicator that a catalog is known to a node and possibly related to catalog references on other nodes.
clustering key Glossary clustering key. A storage key made up of a set of columns in a table whose values act as logical row-ids. The set of columns that make up the clustering key must guarantee uniqueness. See also primary key. COBOL preprocessor. See SQL preprocessor. collation. A convention that governs the ordering of any two character strings formed with characters from their character sets. SQL/MX supports only the default collation that is based on binary ordering. See also character set. column.
compiled module Glossary compiled module. See module. concurrency. Access to the same data at the same time by two or more processes. concurrent access. The ability of two or more processes to gain access to the same data at the same time. See also read uncommitted access and read committed access configuration client library. An administrative library for MXCS with a programmatic interface. It connects to MXCS components and passes administrative commands and responses back and forth.
cursor position Glossary cursor position. The current position of a cursor before, at, or after a row in a set of selected rows. cursor stability. The guarantee that a row at the current cursor position cannot be modified by another program. For SQL/MX to guarantee cursor stability, you must specify SERIALIZABLE access for the SELECT statement that defines the cursor. customizer. See SQLJ customizer. D DAM parallelism.
data source Glossary data source. The data a user wants to access and the associated operating system, database management system (dbms), and network platform used to access the dbms. To manage ODBC client access to SQL/MX data, you can add, configure, and delete ODBC/MX data sources on both the HP NonStop system and the client computer. data type. A set of valid values with an associated data format. All values in a column must conform to the format of the column’s data type.
DDL statement Glossary DDL statement. A statement used to define, delete, or modify the SQL definition of an object, catalog, or to change the authorization to use the object, catalog, or schema. Contrast with DCL statement and DML statement. deadlock. A block to data access caused by processes contending for the same data.
distributed database Glossary distributed database. A database whose objects reside on more than one node in a network of nodes and whose objects can be accessed from any node in the network. distributed transaction. A transaction that accesses data located on multiple nodes of a network, or one that accesses data by means of requesters or servers at multiple nodes of a network. distribution service. When used in SQL/MX error messages, refers to the SQL/MX file system. DML. Data Manipulation Language.
entry-sequenced table Glossary Records can be added or updated but not deleted, but variable-length values cannot be shortened or lengthened. Entry-sequenced files can be used only with SQL/MP. Contrast with key-sequenced file. entry-sequenced table. A table stored in an entry-sequenced file and whose primary key is a system-generated record address. Entry-sequenced tables can be used only with SQL/MP tables. Contrast with key-sequenced table. environment variable.
execution plan Glossary of information about the execution upon completion. Each SQLJ clause in a Java program is implicitly or explicitly associated with an execution context. execution plan. An execution method, including the semantics and execution characteristics, for a single compiled SQL statement. The SQL compiler stores the execution plan in an SQL module during explicit compilation, and the SQL executor uses the plan to execute the SQL statement at run time.
field Glossary named CAT.SCH.MOD, when externally qualified with the table set tabset1, version ver3, and group grp2, becomes CAT.SCH.GRP2^MOD^TABSET1^VER3. For more information, see the SQL/MX Programming Manual for C and COBOL or the SQL/MX Programming Manual for Java. F field. A portion of a record reserved for a specific item of information. In relational terms, each column of a table represents one field.
grouped select Glossary grouped select. A query that generates a single row in the result table by processing a set of rows from the table produced by the FROM clause. The grouping is determined by a GROUP BY clause, a set (or aggregate) function in the select list, or a grouped view in the FROM clause. The SELECT operation can result in one group (if no GROUP BY clause is specified) or a set of groups. grouped view.
host language Glossary host language. Any programming language whose statements can be combined with SQL statements in the same source program. SQL/MX supports C, C++, COBOL, and Java as host languages. host language compiler. The C, C++, COBOL or Java compiler. host program. A source program that contains both host language statements and embedded SQL statements. host variable.
inner query Glossary inner query. A subquery nested within a statement or another subquery. See also outer query and subquery. inner table. In the evaluation of a join, the table that the executor accesses after the outer table. INOUT parameter mode. The mode of a parameter that passes data to and accepts data from a user-defined routine. Contrast with IN parameter mode and OUT parameter mode. Insert/update/delete. A group of three operations that are used to change data in SQL/MX tables.
Java Database Connectivity (JDBC) Glossary Java Database Connectivity (JDBC). The Java standard for access to relational databases such as SQL/MP or SQL/MX. Java method. A function defined in a Java class. Java object. An instantiation of a Java class. Java Virtual Machine (JVM). Software that loads, links, verifies, and interprets Java bytecode. join. A database operation that combines two or more tables into a single logical table so that data can be selected from all the tables at once.
leaf operator Glossary leaf operator. An operator in an operator tree that has no children. An example of a leaf operator in an operator tree is the scan node. The EXPLAIN row for a relational leaf operator will have NULL value for the left and the right child column. left hybrid hash join. A left hybrid hash join returns an unmatched outer row even when it does not find a match in the inner table. Null values are supplied for the missing inner rows.
lock escalation Glossary lock escalation. The replacement of all the row locks on a partition or table by a single partition lock or table lock when the number of row locks approaches a limit. See also lock granularity. lock exclusion mode. A lock attribute that determines whether any process except the lock holder can access the locked data. See also exclusive lock and shared lock. lock granularity. The size of a lockable unit.
Microsoft ODBC driver manager Glossary Microsoft ODBC driver manager. An ODBC component that manages access to ODBC drivers for ODBC applications. The driver manager loads and unloads ODBC drivers and passes calls for ODBC functions to the correct driver. ODBC/MX uses the Microsoft 3.0 (or later) Driver Manager. Microsoft ODBC server. An ODBC component in the client/server architecture that stores, retrieves, and protects data in the database.
module language Glossary module language. A language for expressing SQL operations in pure SQL syntactic form used in module definition files and embedded module definitions. module management qualified module name. See externally qualified module name. Module TableSet Specification String (MTSS). A regular identifier used by the Module Management subsystem to represent a table set or target.
MXSQLCO Glossary MXSQLCO. The SQL COBOL preprocessor. See SQL preprocessor. MXUDR. The SQL/MX UDR server. See also SQL/MX UDR server. MXV. See SQL/MX software version (MXV). N name resolution. The process of resolving names in a statement by mapping logical names to their physical names and expanding partially qualified object and schema names by using the current default values. namespace. A logical naming scheme for grouping related types.
nonsensitive command. Glossary nonsensitive command. A SQL/MX connectivity service (MXCS) administrative command that returns only the status or attributes of objects in the MXCS subsystem being administered. Contrast with sensitive command. NonStop Data Access Manager. See Data Access Manager (DAM). NonStop ODBC driver. A Microsoft ODBC component needed for an ODBC application to communicate with a server. ODBC drivers are DLLs and are loaded on demand. NonStop ODBC/MX.
NonStop SQL/MP Glossary NonStop SQL/MP. See SQL/MP. NonStop SQL/MX. See SQL/MX. NonStop SQL/MP conversational interface. See SQLCI. NonStop SQL/MX conversational interface. See MXCI. NonStop TMF product. See Transaction Management Facility (TMF). normalizer.
object schema version (OSV). Glossary object schema version (OSV). The schema version of a database object’s schema. The version is assigned to the object at create time and changes when the object’s schema is upgraded or downgraded. OFV. See object feature version (OFV). OLT optimization. A method of optimizing online transaction processing performance and influencing SQL query performance.
OUT parameter mode Glossary OUT parameter mode. The mode of a parameter that accepts data from a user-defined routine (UDR). In an SQLJ program, this mode specifies a host variable or expression that accepts data from an SQLJ clause. It is the default mode if the host expression is part of an INTO list or an assignment expression. Contrast with IN parameter mode and INOUT parameter mode. outer query. A statement containing a subquery or a subquery containing another subquery.
plan fragment Glossary plan fragment. A portion of a query execution plan that executes within a single process such as DAM, ESP, or master executor. policy file. A file that instructs the Java security manager to allow certain restricted operations. positioned iterator. A type of iterator where the data types of columns in the iterator declaration correspond in order to the data types of columns in the result table. Contrast with named iterator. See also iterator. precision.
program independence Glossary program independence. The ability to change an application without changing the database. Contrast with data independence. programmatic SQL. The SQL statements and directives that can be embedded in a hostlanguage program; the application programming interface for SQL/MX. Contrast with MXCI. publish. To insert rows of data into a queue or channel by using an INSERT or UPDATE statement. Q query.
read committed access Glossary read committed access. An access option for any DML statement that requires that the data being accessed is from committed rows. SQL/MX requires that a lock can be acquired on the data requested by the DML statement, but does not actually lock the data, thereby reducing lock request conflicts. If a lock cannot be granted (implying that the row contains uncommitted data), the DML statement request waits until the lock in place is released.
repeatable read Glossary repeatable read. The level of consistency that repeatable read access provides. Contrast with cursor stability. See also repeatable read access. repeatable read access. An access option for transaction consistency that ensures that the data accessed by a transaction cannot be changed by other users until the transaction ends. With repeatable read access, a process tests for existing locks on data before acquiring its own lock and holds the lock until the transaction completes.
savepoint Glossary S savepoint. A marker that allows an application to roll back part of a transaction if a minor error is encountered. The application must still commit or roll back the full transaction when it is complete. scale. A positive integer that represents the number of digits to the right of the decimal point in the evaluation of an arithmetic expression. Contrast with precision. schema. A named collection of SQL/MX database objects.
session attribute Glossary session attribute. One of a set of attributes consisting of parameters and options whose values describe the current MXCI session. set function. A function that operates on a group or groups of rows retrieved by the SELECT statement or the subquery in which the set function appears. Also called an aggregate function. shared lock.
SQL conversational interface (SQLCI) Glossary SQL conversational interface (SQLCI). See SQLCI. SQL declare section. A section within a C or COBOL program used to declare host variables. An SQL declare section begins with BEGIN DECLARE SECTION and ends with END DECLARE SECTION. SQL descriptor area. An area that contains multiple item descriptor areas, together with a count of the number of areas.
SQL program Glossary with the SQL statements converted to comments and an SQL module definition file. These two files are submitted to the host language compiler and to the SQL compiler respectively. SQL program. A host-language program containing embedded SQL statements to be compiled by the SQL compiler. SQL source file. A file written in C, C++, COBOL, or Java, containing both SQL and programming language constructs. SQL statement execution time.
SQL:2003 Glossary SQL:2003. The American National Standards Institute (ANSI) version of SQL (structured query language) that includes additional object-oriented features. SQL:2003 is the latest version of the standard. SQL:2003 enables developers to apply SQL databases to problems that are too complex to address with the older, purely relational paradigm. SQL/MP. The NonStop relational database management system (RDBMS) that was first introduced in 1987.
SQL/MX optimizer Glossary SQL/MX optimizer. See optimizer. SQL/MX software version (MXV). The version of the SQL/MX system software that is installed on a node. SQL/MX UDR server. A layer of software between the SQL/MX executor and a Java Virtual Machine (JVM) that provides support for a stored procedure in Java (SPJ) in SQL/MX. Also refers to a running instance of the MXUDR program in which SPJ methods are executed by an embedded Java Virtual Machine (JVM). statement atomicity.
super ID Glossary super ID. A special user ID defined for each node that has NonStop operating system user name SUPER.Super and user ID 255, 255. The super ID can act as the owner of any object or file on the node. swap file. A disk file used by the system for virtual memory. SYSKEY. A storage key defined by the system rather than by the user. See also clustering key. SYSTEM_DEFAULTS.
timestamp check Glossary timestamp check. A comparison performed by SQL/MX of the current redefinition timestamp of a table in an SQL statement with the table’s compile-time timestamp to determine if the table has changed since the last explicit SQL compilation. If the redefinition timestamp of the table has changed, SQL/MX automatically recompiles the SQL statement if it fails the similarity check (or if the similarity check is not enabled). TMF. See Transaction Management Facility (TMF). TNS/R native.
trigger temporary table Glossary trigger temporary table. A pseudo-temporary table created to implement triggers efficiently. These tables are not temporary tables, as defined by ANSI, but an implementation used to help execute triggers. tuple. A data object containing two or more components. type checking. Determines whether data types are compatible. See also compatible data types. type 1 plan. A parallel execution plan in which matching partitions exist in tables that are involved in a join.
user metadata tables Glossary user metadata tables. For SQL/MX, these metadata tables reside in user schemas. The HISTOGRAM and HISTOGRAM_INTERVALS tables contain histogram statistics for user tables within a database. One set of these tables resides in each user schema. The SYSTEM_DEFAULTS table contains default settings for query execution options. There is one SYSTEM_DEFAULTS table on each node where SQL/MX is installed.
worktable Glossary worktable. An internal object that is visible through one or more physical NonStop operating system files. SQL/MX worktables handle special features supported in SQL/MX, such as triggers.
worktable Glossary HP NonStop SQL/MX Glossary—523732-002 Glossary -42
