QuerySurge and BLOB Data

Versions: 8.0+

The BLOB Data Type - Binary Large OBjects

Most database and data store products have a data type for storing large binary objects, often called BLOBs (Binary Large OBject). These objects are typically 2 GB of binary data or more, depending on the specific data technology you are using. Obviously, a resultset with even a single column of BLOBs may represent a  large data payload, and a resultset with multiple BLOB columns may represent an extremely large payload.

Note: Your specific database or data store technology may use a different term for this data type. For example, Oracle calls this type a BLOB, while in SQL Server, it is an IMAGE type.

QuerySurge and BLOBs

QuerySurge handles data typing by checking query data types from the query metadata for each of the columns in your queries. So, if you have a BLOB column in a table, it is typed as a BLOB by QuerySurge because the metadata has indicateed that the column is a BLOB. When your query returns a BLOB column, instead of pushing the entire data set to your browser, which may have significant negative network and/or browser impacts (it could be ≥ 2GB of data per row), QuerySurge simply shows you "{blob}" notation when you view your data:

It is important to note that, when QuerySurge shows you the "{blob}" notation, your data has been acquired by QuerySurge, and the QuerySurge comparison has run on your data. You can see BLOB data cell-by-cell, by choosing a cell in your data popup, and right-clicking on it. Using the context menu, you can save the BLOB data to a file:

It is important to note that this option only lets you download the BLOB data cell-by-cell, to avoid unacceptably large downloads (for example, downloading an entire column or table of BLOBs to your browser), which could have negative effects on your network and on browser memory, and on local disk usage as well.

Note: Because BLOBs are simply an ordered collection of bytes as far as QuerySurge is concerned, QuerySurge does not know the file type involved. Since any type of data may be a BLOB, including image data (e.g., .png, .jpg, .gif, .tiff, .bmp files), text data, or other file data (e.g. MS Word .docx files or Excel .xlsx files, etc.), you may need to determine the data type you are dealing with, and save it with an appropriate file extension in order for your OS to recognize the file.