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Thread: How does the Oracle RDB driver handle metadata?

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    How does the Oracle RDB driver handle metadata?

    How does the Oracle RDB driver handle metadata? :confused:

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    Andre is offline Documentation Manager
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    Wink Metadata in Oracel RDB

    The Oracle RDB data source driver polls the Oracle RDB database for required metadata. Following the relational model, metadata definitions reside on a dedicated system table that are accessed by ordinary SQL queries. In this regard, system tables of interest are RDB$RELATIONS holding information about tables and, RDB$ROUTINES where procedures are maintained.
    A metadata query issued by the data source driver for a table listing can look as follows:

    SELECT RDB$RELATION_NAME, RDB$DESCRIPTION FROM RDB$RELATIONS

    Detailed table/record information-fields, types and alike, are sampled by querying the table and describing its contents by standard programmed techniques. The following statement sequence illustrates this symbolically:
    Set recqry_str to "SELECT * FROM EMPLOYEES"
    PREPARE record_query FROM recqry_str;
    DESCRIBE record_query INTO rec_sqlda;

    Now the rec_sqlda structure holds the mapping of EMPLOYEES table.

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