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EPIC Database Management

EPIC data management and data access on Unix with mSQL database

EPIC data residing on UNIX workstation disks can be managed with mSQL database for any mSQL supported UNIX system as well as an INGRES database on an INGRES licensed server machine. The EPIC database contains metadata from the data files. The data itself resides in individual disk files and is not entered into EPIC database. EPIC database contains metadata and pointers to the individual data files. The data files can be located at any machine, but loading the EPIC database requires that the data disks be mounted by the INGRES licensed machine or mSQL server machine so that metadata from the data file can be loaded directly into the EPIC database.

Refer to PMEL's EPIC INGRES database home page for detailed information about INGRES database management.

MSQL is mini SQL, a light weight database engine developed by David J. Hughes <bambi@hughes.com.au> at Bond University, Australia. It has been designed to provide fast access to stored data with low memory requirements. As its name implies mSQL offers a subset of SQL as its query interface. Although it only supports a subset of SQL, everything it supports is in accordance with the ANSI SQL specification. The mSQL is a shareware and can be obtained via anonymous ftp from Bond University, Australia.

The information loaded into mSQL EPIC database includes the path and name of the data file, geographic range, depth range, time range, cruise ID, cast number, etc. This information can be retrieved by a user via the EPIC selection programs on any networked UNIX machines. The metadata in the mSQL can be accessed by one the following methods:

• Using command line interactive selection program
• Using World Wide Web browser
• Using Motif based X-window application

The mSQL database engine contains internal RPCs that work in a client/server environment over a TCP/IP network. The EPIC/mSQL database data selection program (the client procedures) send the selection query parameters and search constaints with RPC calls to the mSQL server machine. When the server machine receives the message, its service daemon will invoke the service procedure to search the mSQL database, select the data file, and then send the result back to the client procedure. When client procedure receives the message from the server, the results of the procedures are exracted to generate the pointer file (list of data files meeting the users selection criteria) on the local system.

The lastest version of mSQL EPIC database software package is available in the following ftp directory: