What Is a DB Scanner?

A DB scanner, or Database scanner, is a tool or component designed to interact with databases to access and process data, particularly unstructured content stored within or referenced by the database.

Understanding Database Scanners

In essence, a Database scanner acts as an interface between content processing systems and the data residing within a database management system (DBMS). Databases often contain more than just structured data like numbers and text strings; they can also store large binary objects (BLOBs) or character large objects (CLOBs), which might contain documents, images, videos, or other complex data types.

According to the provided reference:

The Database scanner can extract BLOB or CLOB content from a database or use the content files on disk, get their path via the query and use it during the transformation process via the mc_content_location system attribute.

This highlights key capabilities:

1. Direct Content Extraction: It can pull the actual BLOB or CLOB content directly out of the database.
2. Disk File Handling: It can work with content stored as files on disk, where the database only holds the file path. The scanner can execute a query to retrieve this path.
3. Integration with Processing: It facilitates the use of this extracted or located content in subsequent processing steps (like transformation or indexing) by utilizing system attributes such as mc_content_location to point to the content's source or location.

Why Use a DB Scanner?

Organizations use DB scanners for various purposes related to managing and utilizing content stored within databases:

• Indexing Unstructured Data: Enabling search engines or indexing systems to find and index documents, images, or other files stored as BLOBs/CLOBs or referenced via file paths in a database.
• Content Migration: Extracting content for migration to new systems or storage solutions.
• Data Analysis: Accessing and processing large content items for analysis or reporting.
• Data Transformation: Preparing content for use in other applications or formats.

Key Features and Functions

Database scanners typically offer features like:

• Database Connectivity: Support for connecting to various database types (e.g., SQL Server, Oracle, MySQL).
• Query Execution: Ability to run custom SQL queries to select specific records and retrieve content or file paths.
• Content Retrieval: Methods to efficiently extract large BLOB/CLOB data.
• File Path Resolution: Using query results to locate content files on network drives or local file systems.
• Metadata Association: Linking the extracted content with associated structured metadata from the database record.
• Output Integration: Providing the content and metadata in a format suitable for downstream processing systems.

Example Scenario

Imagine a company stores customer contracts (PDF files) as BLOBs in an Oracle database table, along with customer metadata (name, ID) in other columns. A DB scanner could be configured to:

1. Connect to the Oracle database.
2. Execute a query like SELECT customer_id, contract_blob, file_name FROM contracts_table WHERE status = 'active'.
3. Extract the contract_blob (the PDF content) and the customer_id and file_name metadata for each active contract.
4. Pass this content and metadata to an indexing system, potentially using mc_content_location to point to a temporary file where the BLOB was saved, allowing the indexer to process the PDF.

This process makes the content searchable and accessible, even though it was originally embedded within the database.