Data loading, data unloading, and file staging DML commands: Single-character pattern matches (Postponed)¶
This behavior change was originally planned for February, 2021; however, it has been postponed and a new release date has not been determined.
For the most up-to-date details about the release date, as well as other release-related details, see the Behavior Change Log.
The PATTERN parameter filters the set of staged files in the output of the following DML commands using a regular expression:
COPY INTO <location>
COPY INTO <table>
In a future release, the behavior of the PATTERN parameter will change as follows:
When the regular expression is matched against the file path, an additional internal path is incorrectly prepended to the file path. As a result, some regular expressions incorrectly match characters not included in the specified internal path.
For example, the LIST command could filter filenames against a PATTERN regular expression that matches the letter “t”:
LIST @mystage pattern='.*t.*';
This LIST statement returns all filenames in the stage, even if the files don’t contain the letter ‘t’, because the incorrectly prepended path contains the letter ‘t’.
The source of the issue is an internal/hidden path that the commands apply to all files in a stage. The PATTERN regular expression includes this path when evaluating the filenames in the command output.
The PATTERN parameter ignores the internal/hidden path when evaluating the filenames in the command output. The regular expression only matches the customer-created paths and filenames in the stage.