Locking During a Copy
When you use the COPY statement, the locking system takes one of the following actions:
• A Shared lock on the table while data is being copied into a file
• An Exclusive lock on the table during bulk copies to the table, for maximum speed
• An Intent Exclusive lock on the table during an incremental copy to the table. Because inserts are used to update the table, the copy can encounter lock contention.
For a complete explanation of locking, see the chapter “Understanding the Locking System.”