Opening a new cursor is a relatively expensive operation in WiredTiger (especially in table objects and Log-Structured Merge Trees (LSM) trees, where a logical cursor may require multiple, underlying object cursors), and caching cursors can improve performance.

On the other hand, cursors hold positions in objects, and therefore long-lived cursor positions can decrease performance by blocking page eviction or looking like a long-lived transaction.

One solution is to cache cursors, but use the WT_CURSOR::reset method to discard the cursor's position in the object when the position is no longer needed. And, use the WT_CURSOR::insert method instead of the WT_CURSOR::update method, when there's no reason to track a position in the object, because the WT_CURSOR::insert method never maintains a cursor position, so there's no need to call WT_CURSOR::reset.

Additionally, cursors are automatically reset whenever a transaction boundary is crossed; when a transaction is started with the WT_SESSION::begin_transaction or ended with either WT_SESSION::commit_transaction or WT_SESSION::rollback_transaction, all open cursors are automatically reset, there is no need to call the WT_CURSOR::reset method explicitly.