Table of Contents
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1 Introduction
The Neoview SQL database software allows you to use SQL statements, which comply closely
to ANSI SQL:1999, to access SQL databases.
This introduction describes:
•
"SQL Language"
•
"Security"
•
"Data Consistency and Access Options"
•
"Database Integrity and Locking"
•
"Transaction Management"
•
"ANSI Compliance and Neoview SQL Extensions"
•
"Neoview SQL Error Messages"
Other sections of this manual describe the syntax and semantics of individual statements,
commands, and language elements.
SQL Language
The SQL language consists of statements and other language elements that you can use to access
SQL databases. For descriptions of individual SQL statements and SQL utilities, see
"SQL Statements" (page 37)
SQL language elements are part of statements and commands and include data types, expressions,
functions, identifiers, literals, and predicates. For more information, see
Elements" (page 233)
functions and expressions, see
Chapter 7: "OLAP Functions" (page
Security
For information about database security, see the Neoview User Management and Security Guide.
Data Consistency and Access Options
Access options for DML statements affect the consistency of the data that your query accesses.
For any DML statement, you specify access options by using the FOR option ACCESS clause
and, for a SELECT statement, by using this same clause, you can also specify access options for
individual tables and views referenced in the FROM clause.
The possible settings for option in a DML statement are:
"READ COMMITTED "
"READ UNCOMMITTED "
"SERIALIZABLE or REPEATABLE READ"
"SKIP CONFLICT"
The SQL default access option for DML statements is READ COMMITTED.
The implementation for REPEATABLE READ and SERIALIZABLE access options is equivalent.
and
Chapter 3: "SQL Utilities" (page
and
Chapter 5: "SQL Clauses" (page
Chapter 6: "SQL Functions and Expressions" (page 337)
491).
211).
Chapter 4: "SQL Language
313). For information on specific
Specifies that the data accessed by the DML statement
must be from committed rows.
Specifies that the data accessed by the SELECT statement
need not be from committed rows.
Specifies that the DML statement and any concurrent
process (accessing the same data) execute as if the
statement and the other process had run serially rather
than concurrently.
Allows transactions to skip rows locked in a conflicting
mode by another transaction. SKIP CONFLICT cannot be
used in a SET TRANSACTION statement.
Chapter 2:
and
SQL Language
25
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