The Query Processor is a Structured Query Language (SQL) parser, optimizer, and query execution engine. The Query Processor accepts and executes SQL commands according to a chosen plan and interacts with the Enterprise Database Server storage engine to return the expected results.
The optimizer chooses the fastest execution plan. In the optimization phase, the Query Processor chooses
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Any indexes to use
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The order in which joins are executed
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The order in which constraints (such as WHERE clauses) are applied
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The algorithms that lead to the best performance
The query execution engine executes the query plan chosen during query optimization. The execution engine also determines the algorithms available to the query optimizer. For example, the Query Processor implements an indexed-loop join algorithm.
The Query Processor enables you to
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Access business-critical data stored in the highly robust and scalable Enterprise Database Server using standard SQL commands from JDBC, ODBC, COBOL, or ALGOL applications.
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Create SQL databases that can be queried using the SQL data manipulation language (DML)
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Build, deploy, and manage applications on your ClearPath MCP server that are secure, scalable, and reliable.
The Query Processor is compliant with the SQL-92, entry level with extensions, data manipulation language (DML) as defined by the American National Standards Institute (ANSI) document X3.135-1992, “Database Language SQL.” The Query Processor provides an ALGOL and a COBOL call-level application program interface (API) that conforms to a subset of the SQL-99 call-level interface (CLI). Administration tools are provided to
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Create a relational view of an existing Enterprise Database Server database.
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Create an SQL database based on an SQL data definition language (DDL).
Benefits of Using the Query Processor
The Query Processor provides the following benefits:
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Reduced network traffic
The Query Processor runs entirely on the ClearPath MCP server. This feature eliminates any network traffic that would result from switching between the ClearPath MCP server and a Windows or other server.
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Scalability
The Query Processor is scalable and supports multiple user sessions at the same time.
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Simplified enterprise development
Using the COBOL or ALGOL API or the JDBC or ODBC interface, you can easily develop applications to interface to the Enterprise Database Server.
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Comprehensive software localization
International customers are able to interact with the Query Processor and its tools on all levels, in their own language, and using their own cultural conventions. Localization entails translation of all dialog boxes, on-line help, error messages, and other user interface text.
The Query Processor supports various character sets and collation based on the Unisys CCSVERSION defined for the Enterprise Database Server database. Using the Query Processor administration tools, you can specify the coded character set (CCS) to be used when connecting to the database and when translating database data and identifiers to and from Unicode.
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Secure communications
The Query Processor supports secure communication using the Transport Layer Security (TLS) cryptographic protocol to interact with Query Processor components.
Components and Capabilities
The Query Processor provides the following components and capabilities:
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The Query Design Center is an interactive query tool that developers and system administrators can use to issue queries against the Enterprise Database Server. This tool makes it easy to develop and design queries against Enterprise Database Server databases and test them outside of user applications.
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The Relational Design Center is an interactive schema administration tool that enables SQL access to Enterprise Database Server databases. Database administrators can import, define, and save schema modifications. Schema administration functions include
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Generating an SQL schema for Enterprise Database Server databases
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Defining and modifying schema attributes to be used for mapping an Enterprise Database Server description file
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Diagnosing errors including error reporting, event logging, and tracing
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Call-Level Interface (CLI)
The CLI is a single, open SQL API that enables a client application on a ClearPath MCP system to access Enterprise Database Server databases. CLI interfaces include JDBC, ODBC, COBOL, and ALGOL.
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Module language
The module language supports the SQL module language interfaces. The module language enables you to partition and centralize code and develop routines that can be called by other applications.
