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o'reilly - oracle sql the essential reference

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Oracle SQL The Essential Reference [...]... Foreword xxiii • Entry SQL- 92 contained only features from SQL- 89 • Intermediate SQL- 92 added about half of the new features • Full SQL- 92 represented the complete standard Both the SQL- 86 and SQL- 89 standards defined a subset of the SQL language as it was implemented in commercial database products In contrast, when it was defined, the SQL- 92 standard anticipated developments in SQL products, and still... respects PL /SQL first appeared for client-side use (in Oracle s SQL* Forms) in 1988, and with Oracle7 in 1992 for triggers and stored procedures that execute within the database The Evolution of SQL: the 1990s and Beyond If the 1970s was the decade of SQL invention, and the 1980s was the decade of SQL commercialization, then the 1990s was the decade of SQL evolution During this period, the various vendors... specification of the language If the SQL language is the Rosetta stone that unlocks access to the world’s information, then the SQL standard document is something of a Rosetta stone itself Other than vendor documentation, the SQL standard provides the only formal, complete definition of the syntax and semantics of the SQL language The history of the standards process is interesting In the 1950s, the U.S Department... automatically by systems implementing the standard The Integrity Enhancement Feature was incorporated into the 1989 revision of the SQL standard that also included a specification for embedding SQL in COBOL, Fortran, and C The next standard was adopted in 1992 and is known as SQL- 92 SQL- 92 added numerous capabilities to the SQL language, including outer joins, date-time and other datatypes, standardized error... presented together Chapter 6, SQL* Plus, presents Oracle s standard interface to the SQL language SQL* Plus is such an integral part of Oracle that no programmer can do without it This chapter provides a summary of the use of this product that I hope conveys the power of SQL* Plus.* Chapter 7, PL /SQL, provides a concise definition of the structure and syntax for the basic elements of PL /SQL, as well as the basic... addition to the core functionality of SQL/ Foundation, the SQL committee has developed other parts of the SQL specification, including some that utilize the object model now part of SQL Briefly, these include the following parts of SQL1 999: • SQL/ PSM (persistent stored modules): procedural language capabilities for looping, branching, procedure invocation, and dynamic exception handling • SQL/ OLB (object... including many of their arbitrary restrictions The document defined the basic SQL language, including the ability to CREATE tables and views, but not the ability to DROP or ALTER them, nor to GRANT or REVOKE access privileges The lack of referential integrity capabilities in SQL- 86 was a glaring omission, from the viewpoint of relational database advocates Because of the heated criticism, the SQL standards... information about PL /SQL, see Steven Feuerstein and Bill Pribye’s Oracle PL /SQL Programming, 2nd Edition (O’Reilly & Associates, 1998) and the other PL /SQL books in the Feuerstein series This is the Title of the Book, eMatter Edition Copyright © 2000 O’Reilly & Associates, Inc All rights reserved xxx Preface Chapter 8, SQL Statement Tuning, explains how the Oracle kernel actually executes the SQL statements... and the database system determines the precise ways in which the data will be accessed and the sequence of the various processing steps needed to produce the desired result A very useful aspect of SQL is the “closure” property: a query result is generated in the form of a table Therefore, the set of rows returned by a query can be inserted into another table, or used as part of a query expression in SQL, ... (primary) key column(s) In a SQL database, a join operation matches rows from multiple tables by comparing the values of their columns This approach is very much the antithesis of object references that directly point from one object to another Because of the strong differences in their type systems, much has been made of the so-called “impedance mismatch” between SQL and object-oriented programming languages . 1970s was the decade of SQL invention, and the 1980s was the decade of SQL commercialization, then the 1990s was the decade of SQL evolution. During this period, the various vendors with SQL products. of these early users of ORACLE were so impressed with the power of the relational model and the ease of use SQL pro- vided that they often overlooked many of the reliability shortcomings of the. Oracle SQL The Essential Reference

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